Series-stacked switch circuit with voltage glamping and power recovery

Abstract

Various embodiments are directed to a switch circuit comprising: two terminal nodes comprising an upper node and a lower node; a plurality of switch modules connected in series between the upper node and the lower node, each switch module comprising a switch, a rectifier, and a capacitor; a connection circuit coupled to the switch modules; and a power converter coupled to the connection circuit and to a power sink. The switch circuit is configured to limit a voltage or a component of a voltage in the switch circuit and recover power from the voltage limitation, where recovering power includes diverting power from the switch modules, via the connection circuit, to the power converter, and the power converter outputting the power to the power sink.

Description

[Technical field]

[0001] (Related Applications) This application is a continuation-in-part of Application No. 17 / 229,858, filed April 13, 2021, the entirety of which is incorporated herein by reference.

[0002] Aspects of the present disclosure generally relate to power supplies and impedance matching networks. [Background technology]

[0003] Power sources and impedance matching networks that apply power to plasma systems, such as power amplifiers, radio frequency (RF) generators, electron volt type (eV type) generators, impedance matching networks, direct current (DC) power supplies, and alternating current (AC) power supplies, are frequently exposed to damaging events such as sudden changes in the load impedance presented by the plasma system, arcing, and unstable plasma systems. In contrast to damage caused by high dissipation and high current events, where the thermal capacity of the components provides the ability to absorb some of the effects of the event until the control system can react, damage caused by overvoltage events generally occurs much more rapidly than the control system is capable of reacting to. In some cases, for example in silicon carbide devices, overcurrent events can also cause damage more rapidly than the reaction time of many control systems. Circuits that clamp voltage and / or current can temporarily protect sensitive devices, circuits, and systems from overvoltage and / or overcurrent events, but in the process of doing so, the voltage and / or current clamp absorbs power from the circuit, typically limiting the length of time that the clamp can perform the clamping function. Summary of the Invention [Means for solving the problem]

[0004] Various aspects disclosed herein provide voltage and current clamps with power recovery, as well as generators, matching networks, and systems comprising same. The voltage and current clamps of the present disclosure may implement safe and sustainable power recovery to a power reservoir, in contrast to prior art voltage and current clamps that typically divert power to dissipative circuit elements, are constrained by internal circuit heat dissipation rates, and can only operate for short periods of time before overheating, wasting power from clamping into waste heat. The voltage and current clamps of the present disclosure may be capable of clamping voltage and / or current for long or indefinite periods of time, and for periods longer than may be required to provide the amount of voltage and / or current clamping as may be desired within the overall performance envelope of the associated system. The voltage and current clamps of the present disclosure may provide the additional advantage of recovering and recycling power of over-voltage or over-current conditions back to the power reservoir, from which such recovered power may be usefully drawn again, rather than wasting such power on dissipative heating of circuit elements. Systems incorporating such voltage and / or current clamps of the present disclosure may provide these and other specialized advantages in a variety of applications. Systems of the present disclosure incorporating current and / or voltage clamps with power recovery may include single switch and multiple switch systems, RF systems such as RF generators and RF impedance matching networks, other types of generators, series stacked switch circuits, and parallel connected switch circuits, among other systems.

[0005] Various illustrative aspects are directed to a switch circuit including two terminal nodes, including an upper node and a lower node, a plurality of switch modules connected in series between the upper node and the lower node, each switch module including a switch, a rectifier, and a capacitor, a connection circuit coupled to the switch modules, and a power converter coupled to the connection circuit and to a power sink. The switch circuit is configured to limit a voltage or a component of the voltage in the switch circuit and recover power from the voltage limit, where recovering power includes diverting power from the switch module, via the connection circuit, to the power converter, and the power converter outputs the power to the power sink. In some examples, the switch circuit is further configured to limit a component of the voltage across one or more individual switch modules and / or across one or more individual switches of the switch modules. The voltage across the switch may also be referred to as a voltage drop or a voltage difference across the switch.

[0006] Various illustrative aspects are directed to a method including applying a voltage across a plurality of switch modules connected in series between two terminal nodes comprising an upper node and a lower node, each switch module comprising a switch, a rectifier, and a capacitor. The method further includes diverting power from the switch modules through a connection circuit coupled to the switch modules to a power converter coupled to the connection circuit and to a power sink, thereby limiting a component of the voltage across one or more of the switches and / or switch modules, and recovering power from the limiting of the voltage to the power sink.

[0007] Various illustrative aspects are directed to a computing system including one or more processing devices, one or more tangible computer-readable memory devices, and one or more tangible computer-readable data storage devices. The computing system further includes program instructions stored on the one or more data storage devices for execution by the one or more processing devices using the one or more memory devices to configure a switch circuit that applies a voltage across a plurality of switch modules connected in series between two terminal nodes, the plurality of switch modules including an upper node and a lower node, each switch module including a switch, a rectifier, and a capacitor. The computing system further includes program instructions stored on the one or more data storage devices, using the one or more memory devices, for execution by the one or more processing devices to configure the power converter and rectifier to divert power from the switch module through a connecting circuit coupled to the switch module to a power converter coupled to the connecting circuit and a power sink, thereby limiting a component of the voltage across one or more of the switches and / or switch modules, and recovering power from the limiting of the voltage to the power sink.

[0008] Various additional aspects are depicted in and will become more apparent based on the accompanying drawings and described below. [Brief description of the drawings]

[0009] Various features and advantages of the techniques of the present disclosure will become apparent from the following description of specific embodiments of those techniques and as illustrated in the accompanying drawings. The drawings are not necessarily to scale, with emphasis instead being placed on illustrating the principles of the technical concepts. In the drawings, like reference characters may refer to the same parts throughout the different views. The drawings depict only illustrative embodiments of the present disclosure and therefore should not be considered limiting in scope.

[0010] [Figure 1A] FIG. 1A illustrates a block diagram of an exemplary clamp with power recovery, according to an embodiment of the present disclosure.

[0011] [Figure 1B] FIG. 1B illustrates a block diagram of an exemplary voltage clamp with power recovery, according to an embodiment of the present disclosure.

[0012] [Figure 1C] FIG. 1C illustrates a block diagram of an example voltage clamp with power recovery coupled to a protection device and a power sink in accordance with an embodiment of the present disclosure.

[0013] [Figure 2A] 2A-2F illustrate various example rectifier circuits that may be used in conjunction with a voltage clamp with power recovery in various embodiments of the present disclosure. [Figure 2B] 2A-2F illustrate various example rectifier circuits that may be used in conjunction with a voltage clamp with power recovery in various embodiments of the present disclosure. [Figure 2C] 2A-2F illustrate various example rectifier circuits that may be used in conjunction with a voltage clamp with power recovery in various embodiments of the present disclosure. [Figure 2D] 2A-2F illustrate various example rectifier circuits that may be used in conjunction with a voltage clamp with power recovery in various embodiments of the present disclosure. [Figure 2E] 2A-2F illustrate various example rectifier circuits that may be used in conjunction with a voltage clamp with power recovery in various embodiments of the present disclosure. [Figure 2F] 2A-2F illustrate various example rectifier circuits that may be used in conjunction with a voltage clamp with power recovery in various embodiments of the present disclosure.

[0014] [Figure 2G]2G-2J illustrate various filters that may be used in association with a rectifier that may be used in association with a voltage clamp with power recovery in various embodiments of the present disclosure. [Figure 2H] 2G-2J illustrate various filters that may be used in association with a rectifier that may be used in association with a voltage clamp with power recovery in various embodiments of the present disclosure. [Figure 2I] 2G-2J illustrate various filters that may be used in association with a rectifier that may be used in association with a voltage clamp with power recovery in various embodiments of the present disclosure. [Figure 2J] 2G-2J illustrate various filters that may be used in association with a rectifier that may be used in association with a voltage clamp with power recovery in various embodiments of the present disclosure.

[0015] [Figure 3A] 3A-3F illustrate various example power converters that may be used in conjunction with a voltage clamp with power recovery in various embodiments of the present disclosure. [Figure 3B] 3A-3F illustrate various example power converters that may be used in conjunction with a voltage clamp with power recovery in various embodiments of the present disclosure. [Figure 3C] 3A-3F illustrate various example power converters that may be used in conjunction with a voltage clamp with power recovery in various embodiments of the present disclosure. [Figure 3D] 3A-3F illustrate various example power converters that may be used in conjunction with a voltage clamp with power recovery in various embodiments of the present disclosure. [Figure 3E] 3A-3F illustrate various example power converters that may be used in conjunction with a voltage clamp with power recovery in various embodiments of the present disclosure. [Figure 3F] 3A-3F illustrate various example power converters that may be used in conjunction with a voltage clamp with power recovery in various embodiments of the present disclosure.

[0016] [Figure 4A] FIG. 4A illustrates the use of a voltage clamp with power recovery in an RF generator circuit, according to one embodiment of the present disclosure.

[0017] [Figure 4B] FIG. 4B illustrates the use of a voltage clamp with power recovery in an RF impedance matching circuit in accordance with another embodiment of the present disclosure.

[0018] [Figure 4C] FIG. 4C illustrates the use of a voltage clamp with power recovery in an integrated RF generator circuit and impedance matching circuit, in accordance with one embodiment of the present disclosure.

[0019] [Figure 5A] FIG. 5A illustrates an example implementation of a voltage clamp with power recovery in a stacked switch circuit according to an embodiment of the present disclosure.

[0020] [Figure 5B] FIG. 5B illustrates another example implementation of a voltage clamp with power recovery in a stacked switch circuit in accordance with an embodiment of the present disclosure.

[0021] [Figure 5C] 5C, 5D, 5E, 5F, and 5G illustrate example implementations of circuit elements that can help manage or limit peak currents through selected circuit portions in a stacked switch circuit according to embodiments of the present disclosure. [Figure 5D] 5C, 5D, 5E, 5F, and 5G illustrate example implementations of circuit elements that can help manage or limit peak currents through selected circuit portions in a stacked switch circuit according to embodiments of the present disclosure. [Figure 5E] 5C, 5D, 5E, 5F, and 5G illustrate example implementations of circuit elements that can help manage or limit peak currents through selected circuit portions in a stacked switch circuit according to embodiments of the present disclosure. [Figure 5F] 5C, 5D, 5E, 5F, and 5G illustrate example implementations of circuit elements that can help manage or limit peak currents through selected circuit portions in a stacked switch circuit according to embodiments of the present disclosure. [Figure 5G] 5C, 5D, 5E, 5F, and 5G illustrate example implementations of circuit elements that can help manage or limit peak currents through selected circuit portions in a stacked switch circuit according to embodiments of the present disclosure.

[0022] [Figure 6A] FIG. 6A illustrates an example implementation of a voltage clamp with power recovery in a stacked switch half-bridge circuit in accordance with one embodiment of the disclosure.

[0023] [Figure 6B] FIG. 6B illustrates another example implementation of a voltage clamp with power recovery in a stacked switch half-bridge circuit in accordance with one embodiment of the present disclosure.

[0024] [Figure 7] FIG. 7 illustrates another example implementation of a voltage clamp with power recovery in a stacked switch half-bridge circuit in accordance with one embodiment of the present disclosure.

[0025] [Figure 8A] FIG. 8A illustrates another example implementation of a voltage clamp with power recovery in a stacked switch half-bridge circuit in accordance with one embodiment of the present disclosure.

[0026] [Figure 8B] 8B-8F depict various eV type generators that may incorporate stacked switch circuits with voltage clamping and power recovery, according to various demonstrative embodiments. [Figure 8C]8B-8F depict various eV type generators that may incorporate stacked switch circuits with voltage clamping and power recovery, according to various demonstrative embodiments. [Figure 8D] 8B-8F depict various eV type generators that may incorporate stacked switch circuits with voltage clamping and power recovery, according to various demonstrative embodiments. [Figure 8E] 8B-8F depict various eV type generators that may incorporate stacked switch circuits with voltage clamping and power recovery, according to various demonstrative embodiments. [Figure 8F] 8B-8F depict various eV type generators that may incorporate stacked switch circuits with voltage clamping and power recovery, according to various demonstrative embodiments.

[0027] [Figure 8G] 8G and 8H illustrate example implementations of a voltage clamp with power recovery in a stacked bidirectional switch circuit in accordance with an embodiment of the present disclosure. [Figure 8H] 8G and 8H illustrate example implementations of a voltage clamp with power recovery in a stacked bidirectional switch circuit in accordance with an embodiment of the present disclosure.

[0028] [Figure 9] FIG. 9 illustrates a block diagram of an exemplary current clamp with power recovery, in accordance with one embodiment of the present disclosure.

[0029] [Figure 10A] 10A-10G illustrate various rectifier circuits that may be used in conjunction with a current clamp with power recovery in various embodiments of the present disclosure. [Figure 10B] 10A-10G illustrate various rectifier circuits that may be used in conjunction with a current clamp with power recovery in various embodiments of the present disclosure. [Figure 10C]10A-10G illustrate various rectifier circuits that may be used in conjunction with a current clamp with power recovery in various embodiments of the present disclosure. [Figure 10D] 10A-10G illustrate various rectifier circuits that may be used in conjunction with a current clamp with power recovery in various embodiments of the present disclosure. [Figure 10E] 10A-10G illustrate various rectifier circuits that may be used in conjunction with a current clamp with power recovery in various embodiments of the present disclosure. [Figure 10F] 10A-10G illustrate various rectifier circuits that may be used in conjunction with a current clamp with power recovery in various embodiments of the present disclosure. [Figure 10G] 10A-10G illustrate various rectifier circuits that may be used in conjunction with a current clamp with power recovery in various embodiments of the present disclosure.

[0030] [Figure 10H] 10H-10K illustrate various filters that may be used in conjunction with a rectifier that may be used in conjunction with a current clamp with power recovery in various embodiments of the present disclosure. [Figure 10I] 10H-10K illustrate various filters that may be used in conjunction with a rectifier that may be used in conjunction with a current clamp with power recovery in various embodiments of the present disclosure. [Figure 10J] 10H-10K illustrate various filters that may be used in conjunction with a rectifier that may be used in conjunction with a current clamp with power recovery in various embodiments of the present disclosure. [Figure 10K] 10H-10K illustrate various filters that may be used in conjunction with a rectifier that may be used in conjunction with a current clamp with power recovery in various embodiments of the present disclosure.

[0031] [Figure 11A]11A-11F illustrate various power converters that may be used in conjunction with a current clamp with power recovery in various embodiments of the present disclosure. [Figure 11B] 11A-11F illustrate various power converters that may be used in conjunction with a current clamp with power recovery in various embodiments of the present disclosure. [Figure 11C] 11A-11F illustrate various power converters that may be used in conjunction with a current clamp with power recovery in various embodiments of the present disclosure. [Figure 11D] 11A-11F illustrate various power converters that may be used in conjunction with a current clamp with power recovery in various embodiments of the present disclosure. [Figure 11E] 11A-11F illustrate various power converters that may be used in conjunction with a current clamp with power recovery in various embodiments of the present disclosure. [Figure 11F] 11A-11F illustrate various power converters that may be used in conjunction with a current clamp with power recovery in various embodiments of the present disclosure.

[0032] [Figure 12A] FIG. 12A illustrates the use of a current clamp in an RF generator circuit, according to one embodiment of the present disclosure.

[0033] [Figure 12B] FIG. 12B illustrates the use of a current clamp with power recovery in an RF solid-state impedance matching network in accordance with another embodiment of the present disclosure.

[0034] [Figure 13A] FIG. 13A illustrates an example implementation of a current clamp with power recovery in a parallel switch circuit in accordance with one embodiment of the present disclosure.

[0035] [Figure 13B]FIG. 13B illustrates a generator incorporating the use of two parallel switch circuits with current clamps with power recovery in a half-bridge configuration, according to one embodiment of the present disclosure.

[0036] [Figure 14] FIG. 14 depicts a flow chart for an exemplary method embodiment of the present disclosure.

[0037] [Figure 15] FIG. 15 depicts a flow chart for an exemplary method embodiment of the present disclosure.

[0038] [Figure 16] FIG. 16 depicts a flow chart for an exemplary method embodiment of the present disclosure.

[0039] [Figure 17] FIG. 17 depicts a flow chart for an exemplary method embodiment of the present disclosure.

[0040] [Figure 18] FIG. 18 depicts a block diagram of an exemplary computing system that can control the systems and execute the methods in some embodiments of the present disclosure.

[0041] [Figure 19] FIG. 19 depicts a block diagram of an exemplary computing system that can control the systems and execute the methods in some embodiments of the present disclosure.

[0042] [Figure 20] FIG. 20 depicts a flow chart for an exemplary method embodiment of the present disclosure.

[0043] [Figure 21] FIG. 21 depicts a flow chart for an exemplary method embodiment of the present disclosure.

[0044] [Figure 22] FIG. 22 depicts a flow chart for an exemplary method embodiment of the present disclosure.

[0045] [Diagram 23] FIG. 23 depicts a flow chart for an exemplary method embodiment of the present disclosure.

[0046] [Figure 24] FIG. 24 depicts a flow chart for an exemplary method embodiment of the present disclosure.

[0047] [Diagram 25] FIG. 25 depicts a flow chart for an exemplary method embodiment of the present disclosure.

[0048] [Figure 26] FIG. 26 depicts a flow chart for an exemplary method embodiment of the present disclosure.

[0049] [Figure 27] FIG. 27 depicts a flow chart for an exemplary method embodiment of the present disclosure. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0050] (Detailed Description) Embodiments of the present disclosure may provide voltage clamping and / or current clamping circuits with power recovery, such as for clamping the voltage between a protection and reference node and limiting the current in a protection branch in a circuit. By recovering power to a power sink, which may be, for example, a DC bus or an AC utility power source to a building, the clamping circuit can operate in a clamping mode for extended periods of time, unlike clamping circuits that dissipate power to perform the clamping function. Power recovery also improves overall system efficiency. A power converter that maintains a constant input voltage or current for the voltage or current clamping circuit, respectively, allows control over the level at which the voltage or current is clamped, and receives power from the clamping circuit and directs it to the power sink while the clamping operation is active.

[0051] In some embodiments, a circuit for clamping the voltage across each of multiple devices stacked in series and using a special arrangement of diodes to steer current to the input of a single converter allows a single power converter to return power to a power sink while clamping the voltage across each individual device in the stack.

[0052] In some embodiments, a circuit for clamping the current through each of multiple devices in parallel and using a special arrangement of diodes to direct the current to a single power converter allows the single power converter to recover power to a power sink while clamping the current through each individual device connected in parallel.

[0053] In some embodiments, a voltage clamp can be used to limit the maximum voltage across a protection device, such as a metal oxide semiconductor field effect transistor (MOSFET) used in a power amplifier or a capacitor or PIN diode in a solid state match. In some embodiments and applications, there may not be any protection device between the protection and reference nodes that the voltage clamp is limiting, but limiting the voltage between those particular nodes may provide useful functions such as limiting impedance variations or voltages and currents elsewhere in the circuit, among other advantageous functions.

[0054] In some embodiments, a current clamp may be used to enforce a maximum current through a device such as an inductor or the drain current of a MOSFET. In some embodiments and applications, there may not be any protection devices in the current branch that the current clamp is limiting, but limiting the current in that particular branch, as described above with reference to the voltage clamp embodiments, may provide useful functions such as limiting impedance variations or voltages and currents elsewhere in the circuit, among other advantageous functions.

[0055] In this disclosure, "applying a voltage" to or across a device, circuit, or system (e.g., a switch) can mean inducing a voltage across the device, circuit, or system, for example, by opening a switch while current is flowing through the switch and inducing a voltage across the switch due to the current flowing through the increased switch impedance. Similarly, "conducting a current" through or in a device, circuit, or system (e.g., a switch) can mean causing a current to flow through the device, circuit, or system, for example, by closing the switch while a voltage exists across the switch due to a voltage applied across an increased switch admittance, i.e., it is not necessary to use a voltage source to apply a voltage, or a current source to conduct a current, or a power source to apply a power. Any one of a voltage, current, power, a Thevenin equivalent source, etc. can be used to apply any one of a voltage, current, or power.

[0056] FIG. 1A depicts a block diagram of an exemplary clamp with power recovery 100, according to one embodiment. The clamp 100 may function as a voltage clamp with power recovery or a current clamp with power recovery in various embodiments. The clamp 100 includes a rectifier 16 and a power converter 18, which are mutually coupled via internal nodes 10 and 12 on internal branches 11 and 13. The rectifier 16 is coupled to a protection node 6, which is configured to connect to an external protection device, and to a reference node 14. The power converter 18, which includes a controller 19, is coupled to power recovery output nodes 22, 24, and thereby configured to connect to a power sink. The rectifier 16 is configured to connect to the protection device via the protection node 6 on the protection branch 7, and thereby provide voltage clamping of the voltage between the protection node 6 and the reference node 14, or current clamping of the current through the protection device, while providing power recovery via the power recovery output nodes 22 and 24. These functions for both voltage and current clamp embodiments are further described below with reference to several additional embodiments. In some embodiments, no protection devices are present, but either clamping the voltage between the protection node 6 and the reference node 14 or clamping the current in the protection branch 7 provides benefits such as controlling impedance variations, protecting against voltage breakdown, protecting against excessive dissipation, or limiting voltages and currents elsewhere in the circuit or system, among various other novel and useful advantages.

[0057] FIG. 1B illustrates a block diagram of an exemplary voltage clamp 101 with power recovery according to one embodiment of the disclosure. The voltage clamp 101 has a protection node 106 and a reference node 114, and two power recovery output nodes 122, 124. The voltage clamp 101 includes a rectifier 116, a power converter 118, and a capacitor 108. The power converter 118 includes a controller 119 and is coupled to the rectifier 116 via a control voltage node 110 and a control voltage reference node 112. The capacitor 108 is coupled between the control voltage node 110 and the control voltage reference node 112. The rectifier 116 is coupled to the protection node 106 and the reference node 114, and the power converter 118 is coupled to the power recovery output nodes 122 and 124. The voltage clamp 101 may be configured to connect the protection node 106 and the reference node 114 to a power sink (not shown in FIG. 1B) via the power recovery output nodes 122 and 124. The voltage clamp 101 may be configured to limit the voltage or a component of the voltage between the protection node 106 and the reference node 114 by connecting to a protection device (not shown in FIG. 1B) via the protection node 106 and the reference node 114 and diverting power to a power sink via the power recovery output nodes 122 and 124. In various embodiments, the power sink may be external to the voltage clamp 101. In other embodiments, the voltage clamp may include a power sink (not shown in FIG. 1B). The rectifier 116 thus connects the protection node 106 and the reference node 114 to an input of the power converter 118. The power converter 118 is configured to maintain a constant voltage across the input node of the power converter by directing power to the power sink. The capacitor 108 helps maintain the voltage between the control voltage node 110 and the control voltage reference node 112. The capacitor may be a discrete capacitor that is part of the power converter or may not be needed if the power converter is capable of maintaining a voltage at the converter input without the capacitor 108.

[0058] 1C illustrates a block diagram of an example circuit 150 including a voltage clamp 102 with power recovery according to an embodiment of the present disclosure. The voltage clamp 102 connects a protection node 106 and a reference node 114 of the voltage clamp 102 to a power sink 104. The voltage clamp 102 limits a voltage or component of a voltage V113 between the protection node 106 and the reference node 114, including by diverting power to the power sink 104. As explained above, the rectifier 116 connects the protection node 106 and the reference node 114 to an input of a power converter 118. The protection node 106 and the reference node 114 may be considered to be indirectly connected to the input of the power converter 118 in that the protection node 106 and the reference node 114 are not directly connected to the input of the power converter 118, but rather the protection node 106 and the reference node 114 are connected to the input of the power converter 118 through the rectifier 116. The power converter 118 maintains a constant voltage across the power converter's input nodes, i.e., the control voltage node 110 and the control voltage reference node 112, by directing power to the power sink 104 as necessary to maintain a constant voltage across the power converter's 118 input nodes, i.e., the control voltage node 110 and the control voltage reference node 112. In some examples, a controller 162 is connected to or configured within the power converter 118 and executes a control process or method for directing the function of the power converter 118. Any of the functions or effects of the power converter 118 may be performed, executed, or embodied by the controller 162 in various embodiments. The power sink 104 may be, for example, a DC rail in a power amplifier or an AC utility supply. A DC rail or DC bus in this context is a node that is held at a DC voltage with respect to a reference node by a DC power supply and from which power is drawn; for example, a DC power supply may provide 150V between the DC rail and the reference node, and an RF power amplifier may be connected to both the DC rail and the reference node to draw power from the DC power supply and produce RF power.Using a DC rail as a power sink may generally mean that a DC power supply connected to the rail may deliver less DC power than it would have if the rail were not used as a power sink. In the embodiment of FIG. 1C, the voltage clamp 102 also includes a capacitor 108 connected between the power converter input node, i.e., the control voltage node 110 and the control voltage reference node 112. In this embodiment, the capacitor 108 may help maintain the voltage between the control voltage node 110 and the control voltage reference node 112. In various other embodiments, depending on the design of the power converter 118 and the distance between the rectifier 116 and the power converter 118, the power recovery voltage clamp of the present disclosure may not include a capacitor between the control voltage node 110 and the control voltage reference node 112 (as in the embodiment of FIG. 1A).

[0059] Not all nodes need to be distinct nodes. In some embodiments of the power recovery voltage clamp, both the reference node 114 and the control voltage reference node 112 may be embodied in a single node. Terminals of the protection device 111 may connect to the protection node 106 and the reference node 114. These terminals may be, for example, the drain and source or gate and source terminals of a MOSFET device. The protection device may have other terminals, for example, the terminal 120. The design of the rectifier 116 and the power converter 118 may help determine the component of the voltage between the protection node 106 and the reference node 114 that will be limited, of several different voltage components that may be limited. The voltage component that is limited may be, for example, a maximum voltage value, a minimum voltage value, an absolute value of the voltage, a maximum value of a low frequency component of the voltage, or an absolute value of a high frequency component of the voltage, among other potential examples.

[0060] In some embodiments, the voltage clamp 102 may be provided by itself without any protection device attached and capable of being connected to a protection device. In other embodiments, the voltage clamp 102 may include the protection device 111 attached to it. In various embodiments, the voltage clamp 102 may be packaged with the protection device 111, or one or more components of the voltage clamp 102 may be packaged with the protection device 111. For example, the rectifier 116 and the protection device 111 may be packaged together. In another example, the protection device 111, the rectifier 116, and the capacitor 108 may be packaged together. Various components, such as the protection device 111, the rectifier 116, and the capacitor 108, may be packaged together on a substrate, such as a ceramic substrate.

[0061] The system of the present disclosure may thus recover power for future useful purposes. "Recovering power" may include the meaning that power is usefully recovered to be used again. Recovered power is understood in contrast to power that is dissipated, lost to waste heat, or otherwise lost to entropy, is no longer available to apply to a useful function, and is converted into energy that is dissipated over time, rather than power. "Recovering power" may also include the meaning of "recovering energy," or that the energy of power may be recovered into a static storage form, such as a battery, where the energy cannot be applied in a useful physical process over time and therefore does not take the form of power over time. In other words, "recovered power" may include power that the system of the present disclosure recovers and then converts into static energy, which therefore may not then constitute "power" at some interval of subsequent time, since it is static and is not deployed at those later times. In other embodiments, the recovered power may be usefully recovered directly to a power sink, which may generally take the form of dynamic power reservoirs and sources, such as AC power sources, DC power sources, DC rails, or connected batteries, any of which may continue to dynamically provide useful power to any one or more systems in various embodiments. Thus, a "power sink" may generally include such a system capable of receiving the recovered power and usefully delivering the power to a system or device. As another matter, "recovering power" may not necessarily mean recovering the entirety of the power, since it would be physically impossible to implement a realistic electronic circuitry system to maintain perfect thermal balance and absolute zero entropy gain; rather, as used in this disclosure, various embodiments may recover a substantial or significant amount of power or at least a trace amount of power that would otherwise be lost to heat dissipation, entropy, or otherwise non-useful forms as a result of voltage or current clamping.

[0062] 2A-2J show various rectifiers or rectifier modules that may be exemplary embodiments of the rectifier 116 of FIGS. 1B and 1C that may be used as part of or in connection with a voltage clamp with power recovery in various embodiments of the present disclosure, and rectifier module subcircuit elements (e.g., filters) that may embody components of the rectifier 116. The subject matter of FIGS. 2A-2J may be referred to as a rectifier or rectifier module that may include individual discrete rectifiers as circuit elements, and the entire circuitry of each figure may functionally formulate a larger, more complex rectifier that may also be referred to as a rectifier module. As described below with reference to the various figures, the rectifier module may thus include either discrete rectifier circuit elements, or larger blocks of circuitry that include discrete rectifiers and / or rectifiers and / or collectively function as a rectifier, and the rectifier module may be referred to as a rectifier in various embodiments. In the description that follows, various elements may be referenced using both schematic identifiers and patent reference numbers, e.g., voltage v1, 210 and node 1, 202. It should be understood that references to nodes 1-4 or voltages v1 and v2 refer to their own separate and individual elements (e.g., nodes, voltages) across different figures.

[0063] FIG. 2A shows a rectifier 201 capable of limiting voltage v1, 210 to a maximum voltage of voltage v2, 212 plus one diode voltage drop across diode 204, e.g., in some implementations, 0.4 to 1.2 volts. In other embodiments, any diode with any associated diode voltage drop may be implemented. In some cases, diode 204 may be replaced by multiple diodes in series, which may help allow the diode to withstand higher voltages when in the off state. In those cases, the effective diode voltage drop increases. In FIG. 2A, node 1, 202 may embody the protection node 106 of FIGS. 1B and 1C, node 2, 214 may embody the reference node 114 of FIGS. 1B and 1C, node 3, 208 may embody the control voltage node 110 of FIGS. 1B and 1C, and node 4, 216 may embody the control voltage reference node 112 of FIGS. 1B and 1C. The same is true with respect to nodes 1-4 of the exemplary rectifiers 221, 231, 241, 251, 261 of Figures 2B-2F, respectively. That is, the rectifiers 221, 231, 241, 251, 261 are exemplary embodiments of the rectifier 116 of Figures 1B and 1C, respectively, in which the nodes 1-4 may embody the protection node 106, the reference node 114, the control voltage node 110, and the control voltage reference node 112 of Figures 1B and 1C, respectively. Note that with respect to the rectifier 201 of Figure 2A, the reference node 2, 214 and the control voltage reference node 4, 216 are the same node, i.e., they are directly connected by a conductive line. This is also true with respect to the rectifier 221 of Figure 2B, in which the reference node 2 and the control voltage reference node 4 are the same node, i.e., they are directly connected by a conductive line. In other embodiments, such as those for rectifiers 231, 241, 251, 261 of Figures 2C-2F, reference node 2 and control voltage reference node 4 may be separate nodes.

[0064] Rectifier 201 of Figure 2A contains a single diode 204, or multiple series-connected diodes that act like a single diode with a higher effective diode voltage drop and are depicted in Figure 2A as a single diode 204. Rectifier 201 is depicted in Figure 2A as including capacitor 206, which corresponds to optional capacitor 108 of Figures 1B and 1C, although in other embodiments otherwise consistent with Figure 2A, the rectifier may omit a capacitor such as capacitor 206 or may not include a capacitor.

[0065] The rectifier 221 of Figure 2B has a first voltage v1 across the protection node 1, 227 and the reference node 2, 229, and a second voltage v2 across the control voltage node 3, 223 and the control voltage reference node 4, 225. The rectifier 221 of Figure 2B limits the value of the voltage v1 to a minimum value of the voltage difference of voltage v2 minus one diode voltage drop corresponding to the voltage drop across diode 224. The rectifier 231 of Figure 2C limits the amplitude of the voltage v1 (across the protection node 1 and the reference node 2) to voltage v2 (across the control voltage node 3 and the control voltage reference node 4) plus two diode voltage drops. Rectifiers 201, 221, 231, respectively, shown in Figures 2A-2C may be combined with filters (e.g., filter 218 of Figure 2D) as shown in rectifiers 241, 251, 261 of Figures 2D-2F to further select, determine, or embody components of voltage v1 as shown in Figures 2D-2F.

[0066] Some illustrative embodiment topologies for the filters (e.g., filter 218) of Figures 2D-2F are shown in Figures 2G-2J. Filter 220 of Figure 2G contains a single inductor 222 to select the DC component of voltage v1. Using the filter of Figure 2G in the rectifier of Figure 2D would, for example, limit the low-frequency or DC component of voltage v1 to voltage v2+1 diode drops, but allow the AC or RF component of voltage v1 to go above the limit set by the voltage clamp. The filter of Figure 2H contains a single capacitor 228 and a single inductor 226 to select the high-frequency, AC, or RF component of voltage v1. Using the filter of Figure 2H in the rectifier of Figure 2F would, for example, limit the high-frequency, AC, or RF component of voltage v1 to voltage v2+2 diode drops, but would not limit the DC or low-frequency component of v1. With appropriate selection of components, filters 2G and 2H are unlikely to load the circuit in which the voltage clamp is used, i.e., the voltage clamp does not substantially alter the behavior of the circuit when voltage v1 is not within the range in which it is clamped. The filters of Figs. 2I and 2J now load the circuit in which the clamp is used. For example, in an embodiment of the voltage clamp system of any of Figs. 1B and 1C incorporating the rectifier of Fig. 2D, 2E, or 2F with the filter of Fig. 2I or 2J with the guard and reference nodes as described and depicted with reference to those embodiments, the circuit of Fig. 2I creates a low impedance between the guard and reference nodes at high frequencies, and the circuit of Fig. 2J creates a low impedance between the guard and reference nodes at low frequencies.

[0067] 3A-3F show various power converters that may be exemplary embodiments of the power converter 118 of FIGs. 1B and 1C and may be used as part of a voltage clamp with power recovery in various embodiments of the present disclosure, such as the clamp 100, voltage clamp 101, and circuit 150 depicted in FIGs. 1B and 1C. In each of FIGs. 3A-3F, nodes 3 and 4 may correspond to internal nodes, such as the control voltage node and the control voltage reference node, respectively, as in FIGs. 1B and 1C, and nodes 5 and 6 may correspond to the power recovery output nodes of the power converter as depicted in FIGs. 1B and 1C. FIG. 3A shows a step-down converter circuit that may be used when no isolation between voltages v2, 316 and v3, 318 is required (i.e., v2 and v3 may share a common ground reference) and the desired clamp voltage v2 is higher than the sink voltage v3. In FIG. 3A, node 3, 312 may be an embodiment of the control voltage node 110 of FIG. 1B and 1C, node 4, 320 may be an embodiment of the control voltage reference node 112 of FIG. 1B and 1C, and nodes 5, 314 and 6, 322 may be embodiments of output nodes of a power converter configured to be coupled to a power sink such as power sink 104 of FIG. 1C. The same is true with respect to nodes 3 and 4 of FIG. 3B-3F and nodes 5 and 6 of FIG. 3B-3D. In some embodiments, a buck converter may optionally include an input capacitor 306 as shown in FIG. 3A (and similar capacitors shown in FIG. 3B-3F) to help hold the input voltage constant, although in other embodiments, an otherwise similar buck converter may omit such a capacitor between internal nodes 3, 4.

[0068] As shown in FIG. 3A, the buck converter 301 further includes a switch 302, a diode 308, an inductor 304, and an output capacitor 310. The output capacitor 310 may be part of a power sink and / or may also function as part of the buck converter 301. The buck converter 301 may be operated in a manner to maintain the input voltage constant rather than maintaining the output voltage. For example, if the input voltage v2, 316 falls below a desired clamping voltage, the controller 319 may leave the switch 302 in an off or open state until such time that the clamping voltage rises to (or just above) the desired clamping voltage, at which point the controller 319 may begin or resume operation of the switch 302 in a periodic manner (e.g., switching at a frequency of 100 kHz). In some embodiments, the controller 319 may control the switch 302 to implement an increased duty cycle, i.e., the percentage of time that the switch 302 is closed, to reduce the input voltage v2, 316 across the control voltage node 312 and the control voltage reference node 320. Other example methods of operating the switch 302 by the controller 319 may include closing the switch 302 when the input voltage 316 exceeds a desired clamping voltage, opening the switch when the input voltage 316 falls below the desired clamping voltage with some hysteresis, and further opening the switch 302 if the current through the inductor 304 exceeds a nominal or safe level.

[0069] FIG. 3B illustrates a boost converter that may be used as a power converter in various embodiments, such as when no isolation between the clamping voltage v2 and the power sink voltage v3 is required and the clamping voltage v2 is less than the power sink voltage v3. FIG. 3C illustrates a step-down boost converter that may be used as a power converter in various embodiments, such as when no isolation between the clamping voltage v2 and the power sink voltage v3 is required and the power sink voltage v3 for the common nodes 4 and 6 has the opposite polarity of the clamping voltage v2 for the common nodes 4 and 6. FIG. 3D illustrates an isolated DC / DC converter that may be used as a power converter in various embodiments, such as when isolation between the input and output of the power converter is required and the power sink is a DC sink, such as a DC bus. In FIG. 3D, isolation between the input and output of the power converter is achieved using a transformer 324. FIG. 3E illustrates a power converter that may be used in various embodiments, such as when the power sink 330 is a single-phase AC utility source. FIG. 3F illustrates a power converter that may be used in various embodiments, such as when the power sink 340 is a three-phase AC utility source.

[0070] 4A depicts an RF generator 400 including a voltage clamp 407 with power recovery and connected to a load 414 according to another illustrative embodiment. The voltage clamp 407 includes, in this embodiment, a rectifier module 422 and a step-down converter 402. The RF generator 400 also includes a DC power supply 406, a power device 416, and output terminals 413, 415 for coupling to a load such as an RF load 414 (e.g., a plasma chamber). The power device 416 is coupled to the driver 420 and connected to the DC power supply 406 via a network as shown such that the power device 416 can use power from the DC power supply 406, amplify a reference signal received via the driver 420, and deliver the amplified power to the RF load 414 via the network as shown and via the output terminals 413, 415. The RF generator 400 thus constitutes a power amplifier, and any power amplifier embodiment may also be considered a generator as understood in this disclosure. The amplified power generator circuitry connecting the power device 416 to the output terminals 413, 415, in various embodiments, includes a conductive branch through a guard node 408 and a reference node 424 connected to and exposed to a voltage clamp 407, which may thereby clamp the voltage or a component of the voltage within the RF generator. As shown in FIG. 4A, the guard node 408 and the reference node 424 are connected across the power device 416, and thus the voltage across the power device 416 is clamped and the power device 416 becomes a guard device. In other embodiments, the guard and reference nodes may be different nodes and other voltages within the RF generator may also be clamped, including an example where the guard and reference nodes may be the output terminals 413, 415, in which case the output voltage or a component of the output voltage of the RF generator output would be clamped. In an embodiment including a rectifier module 422 and implementing clamping of the output voltage of RF generator 400, the rectifier module 422 as shown is of the type of FIG. 2A which will clamp positive swings in voltage, in other embodiments a rectifier of the type of FIG. 2C or FIG. 2F may be used which may clamp the amplitude of the output voltage of RF generator 400.

[0071] The step-down converter 402 is an embodiment of a power converter, and other embodiments of the RF generator 400 may include other embodiments of a power converter. The rectifier module 422 is connected to the power source, the DC power supply 406, via a first network, i.e., a connection network as shown in FIG. 4A. This connection network connecting the power source and the rectifier module 422 may, in other embodiments, include any of a wide variety of other variations of circuit elements or circuit architectures, and may potentially include simple conductive lines in some embodiments. In other words, the rectifier module may be connected to the power source via a network that, in various embodiments, may include any of a variety of circuit elements or architectures or simple conductive lines, and thus may be indirectly connected to each other, or directly coupled. The voltage clamp 407 further includes, among other circuit elements, a protection node 408 and a reference node 424. (As FIG. 4A shows, the conductive branches of the guard node 408 and the reference node 424 extend from outside to inside the dashed boundary shown for the voltage clamp 407 and the rectifier module 422, and electrically and functionally the guard node 408 and the reference node 424 may be considered equivalently as being coupled to and / or configured within the voltage clamp 407 and the rectifier module 422.) The rectifier module 422 is connected to an external load, the RF load 414, via a second connection network as shown in FIG. 4A, which in this embodiment includes an inductor, a capacitor, and output terminals 413, 415. This connection network connecting the rectifier module 422 and the voltage clamp 407 with the external load may include other variations of circuit elements or circuit architectures in other embodiments.

[0072] The RF generator 400 amplifies power and delivers it to an external load, such as an RF load 414 (e.g., an impedance matching network and a plasma chamber), via output terminals 413, 415. The output terminals 413, 415 for delivering power to a functional load may be distinct from a power recovery output node, as discussed above for outputting recovered power from the step-down converter 402 and voltage clamp 407 to a power sink, such as a DC power supply 406, or as rail 405 in the embodiment of FIG. 4A. The output terminals 413, 415 are connected to the rectifier module 422 via a second network, i.e., a connection network, which in this illustrative embodiment is shown in FIG. 4A, and in various other embodiments, may take the form of any architecture or arrangement of circuit elements and / or direct conductive coupling.

[0073] The RF generator 400 thus includes a power source, i.e., a DC power supply 406, a rectifier module 422 connected to the power source via a first network, a step-down converter 402 connected to the rectifier module 422 and configured to connect to a power sink, i.e., the rail 405 and the DC power supply 406, and output terminals 413 and 415 connected to the rectifier module 422 via a second network. The RF generator 400 is configured to limit the voltage or a component of the voltage across the rectifier module 422, divert power from the voltage limit to the step-down converter 402, and output power from the step-down converter 402 to the power sink, i.e., the rail 405 and the DC power supply 406.

[0074] RF generator 400 thus includes a voltage clamp 407 (including rectifier module 422 and step-down converter 402) in which the RF generator recovers power from clamping to rail 405 and DC power supply 406 instead of diverting excess energy from the clamping voltage. RF generator 400 thus usefully recovers power from voltage clamping and is enabled to engage in voltage clamping for an indefinite length of time instead of being limited to only short duration times as constrained in prior art systems by the heat dissipation limitations of resistors, semiconductor elements, or other circuit elements to which power is typically directed. In various embodiments, other similar generators other than RF generators may also use voltage clamping with power recovery.

[0075] The RF generator 400 may function as an RF power amplifier and may also include a DC power supply 406, a controller 412, and a user interface system (not shown in FIG. 4A), such as, for example, a user multi-level pulsing (MLP) set point input interface. Such an RF generator may provide an RF power source for a plasma reactor for purposes such as, for example, plasma enhanced chemical vapor deposition (CEPVD) processes, plasma enhanced atomic layer deposition (PEALD) processes, etching processes, and other plasma applications. FIG. 4A illustrates the use of a voltage clamp 407 with power recovery to protect a power device 416 in the RF generator 400 from overvoltages. The rectifier module 422, step-down converter 402, protection node 408, and reference node 424 in the embodiment of FIG. 4A may be exemplary implementations of the rectifier 116, power converter 118, protection node 106, and reference node 114 of FIG. 1C. In the embodiment of FIG. 4A, there is a conductive branch along the low-voltage side of the rectifier module 422 between both its low-voltage side power source connection line and its low-voltage side generator output connection line, and therefore there is no voltage difference between the low-voltage side power source connection line and the low-voltage side generator output connection line of the rectifier module 422 at any time (not considering any possible non-ideal circuit effects), so the reference node 424 serves a function similar to both the reference node 114 and the control voltage reference node 112 of the embodiment of FIG. 1C.

[0076] In the example of FIG. 4A, the rectifier module 422 is implemented similarly to the rectifier 201 of FIG. 2A, and the step-down converter 402 is implemented similarly to the step-down converter 301 of FIG. 3A. In other examples, the rectifier module 422 may be implemented similarly to any of the rectifiers of FIG. 2A-2J or other example rectifiers, and the step-down converter 402 may be implemented similarly to any of the power converters of FIG. 3A-3F or other example power converters. The power device 416 of FIG. 4A may be an implementation of the protection device 111 of FIG. 1C. In particular, with the low-voltage side of the power device 416 directly coupled to the low-voltage side of the RF load 414 along a branch that includes the reference node 424, the RF generator 400 and the voltage clamp 407 protect the power device 416 from otherwise potentially damaging instabilities and rapid voltage changes from the RF load 414. 4A, the voltage clamp 407 uses the rail 405 with the rail voltage as its power sink and diverts excess power from the voltage clamping to the rail 405. The rail voltage of the rail 405 is provided by the DC power supply 406 to power the RF generator 400. The rail 405 is a preferred power sink in this embodiment because the power recovered by the voltage clamp 407 cannot exceed the power delivered by the DC power supply 406. In this application, the sink voltage is always less than the clamping voltage and the sink and the clamp can share a common ground reference, therefore the step-down converter 402 can be used as a power converter.

[0077] The rectifier module 422 includes a single diode 410 in this example. In other embodiments, the rectifier module may include any type of rectifier and / or multiple rectifiers and / or may otherwise include circuit elements and / or circuit architectures that result in the rectifier module implementing the ability to function as a rectifier. In such applications involving clamping voltages at mid-to-high RF frequencies (e.g., high frequencies generally in the megahertz or gigahertz range where parasitic inductance and stray capacitance may impose significant engineering factors or constraints on the proper operation of the circuit), the rectifier module 422 may also include a capacitor 426. In other embodiments, the rectifier module as part of a voltage clamping system with power recovery may include other additions or variations of circuit elements in combination with diodes or other rectifiers. The controller 412 controls the buck converter 402 in such a way that the input voltage of the buck converter 402 remains below the desired clamping voltage by a voltage difference equal to the voltage drop across one diode, for example, across the diode 410 of the rectifier module 422. This ensures that the voltage between the protection node 408 and the reference node 424 remains at or below the desired clamping voltage level. The controller 412 may be implemented as a measurement and control (M&C) multiprocessor system on chip (MPSoC), which in some examples may include both a CPU and an FPGA, as well as other elements, together in one integrated SoC.

[0078] The controller 412 may also control the power device 419 to control the buck converter 402 to control the delivery of the power received from the voltage clamping to the rail 405 and the DC power supply 406 as usefully recovered power in this example. In other embodiments, similar power converters may also include other types of switches (e.g., as shown in FIGS. 3A-3F) under the control of a controller to convert the recovered power and control the power converter in outputting the recovered power to a power supply or other useful power sink. The buck converter input voltage across the input node of the buck converter 402 is equal to the voltage difference between the control voltage node 418 and the reference node 424. A capacitor 404 may be included connected to the input of the buck converter 402 to help maintain the buck converter input voltage. This places capacitor 426 and capacitor 404 in parallel with each other, but capacitor 426 may likely be a small capacitor with good high frequency properties (e.g., a 3 nanofarad (nF) ceramic capacitor) mounted close to the protection node 408 and the reference node 424, while capacitor 404 may likely be a larger capacitor with a larger energy storage capability (e.g., a 100 microfarad (μF) electrolytic capacitor). RF generator 400 may contain a driver 420 for driving a power device 416, and the RF power amplifier may be connected to an RF load 414, such as a plasma load. The power device may include a bipolar junction transistor (BJT), a metal oxide semiconductor field effect transistor (MOSFET), a high electron mobility transistor (HEMT), an insulated gate bipolar transistor (IGBT), or other type, in various embodiments. RF load 414 may include a complex implementation, such as, for example, a plasma reactor connected with a sophisticated plasma impedance matching network.

[0079] Although the rectifier module 422 and the step-down converter 402 are embodied in the illustrative embodiment of FIG. 4A as shown in FIG. 4A and described above, they may be embodied in any of several other variations and architectures of rectifier modules and power converters in other embodiments. For example, in the embodiment of FIG. 4A, the rectifier module 422 is embodied similarly to the embodiment of FIG. 2A, while in other embodiments of the generator of the present disclosure, the rectifier module may be embodied as in any of the embodiments of FIG. 2B, 2C, 2D, 2E, 2F, 2G, 2H, 2I, or 2J, or other embodiments. The step-down converter 402 in the RF generator 400 as shown in FIG. 4A is embodied similarly to the step-down converter 301 as shown in the embodiment of FIG. 3A, while other embodiments of the generator of the present disclosure may incorporate a power converter according to that shown in FIG. 3B, 3C, 3D, 3E, or 3F, or any of the other embodiments.

[0080] RF generator 400 is thus configured to provide power from a power source (e.g., DC power supply 406), through an intermediate network, and to output terminals (e.g., output terminals 413, 415). RF generator 400 is further configured to divert power from the intermediate network (e.g., from output terminals 413, 415, rectifier module 422, and a connection network between output terminals 413, 415 and rectifier module 422) to step-down converter 402 to prevent a voltage component in the RF generator from exceeding a voltage component limit (e.g., from a sudden impedance change in RF load 414). The RF generator 400 is further configured to output at least a portion of the diverted power (e.g., the diverted power - nominal power lost to realistic circuit resistance effects, other non-ideal circuit behavior, and / or other sources of inefficiency and entropy) from the step-down converter 402 to a power sink (e.g., the rail 405 and the DC power supply 406) in a usable form (e.g., as DC power with a stable voltage and current that may match the nature of the power on the rail 405 and the DC power supply 406) so that the power sink is configured to reuse the power (e.g., the rail 405 can conduct power to the DC power supply 406, which is enabled to supply that power again to the RF generator 400 instead of a certain amount of power that would otherwise have resulted in a draw from an external energy source, thereby conserving power in its operation and reducing the power consumption involved in its operation). It should be understood that power recovery is subject to nominal engineering limits due to realistic circuit resistance effects, other non-ideal circuit behavior, and / or other sources of inefficiency and entropy, and thus "recovering power" or "outputting power" may equivalently refer to recovering, outputting, diverting, etc. a nominal portion of the "power" or "at least a portion of the power" originally diverted from the generator to the power converter.

[0081] The RF generator 400 may thus be configured in various embodiments to respond to a voltage component reaching a voltage component limit by diverting power to the step-down converter 402, thereby limiting the voltage component at or across the RF generator 400 and / or across a particular portion of the RF generator 400, e.g., between the protection node 408 and the reference node 424, across the rectifier module 422, across the power device 416, or to prevent the voltage component between the protection node 408 and the reference node 424 from rising above the voltage component limit. The RF generator 400 may thus be configured in various embodiments to respond to a voltage component across the rectifier module reaching a voltage component limit by diverting power from the rectifier module to the power converter, thereby limiting the voltage component across the rectifier module. The power converter may be configured in various embodiments to output at least a portion of the power to a power sink, e.g., rail 405, DC power supply 406. The voltage component limit may include the sum of the input voltage of the power converter and the voltage drop of the rectifier module, in various embodiments. In other words, the RF generator 400, in various embodiments, may provide power from a power source, through an intermediate network, to a power output terminal so that the power may be reused, divert power from the intermediate network to the power converter to prevent a component of the voltage from exceeding the voltage component limit, and output at least a portion of the power from the power converter to a power sink. The intermediate network may include a rectifier module, and the voltage component limit may include a voltage limit, and the RF generator 400, in various embodiments, may prevent the voltage across the rectifier module from rising above the voltage limit. The power sink may include a power source, and outputting at least a portion of the power from the power converter to the power sink, in various embodiments, may include outputting at least a portion of the power from the power converter to the power source.

[0082] 4B depicts an RF matching network system 401 with a matching network 430 and a voltage clamp with power recovery 403 according to another illustrative embodiment. In this example, the matching network 430 is a solid-state impedance matching network system that connects the RF generator 432 to the RF load 448. The matching network 430 may be used to match the impedance with fast impedance correction to a nonlinear load typically built into the RF load 448, such as a plasma load in a plasma reactor, which may exhibit nonlinear, time-varying, and chaotic behavior, and thus rapid nonlinear changes in impedance. The matching network 430 may include or be connected to sophisticated detection equipment to rapidly detect such rapid changes in impedance from the load and respond to the detection data by rapidly switching in and out circuit elements, such as a capacitor 434, to match the impedance, and to protect the RF generator 432 from such rapid nonlinear changes in impedance. The matching network 430 contains two variable reactance elements, namely, a switched capacitor array 411 acting as a first variable capacitor and a switched capacitor array 409 acting as a second variable capacitor. In addition, the matching network 430 contains a fixed reactance element, such as an inductor 438. Although this disclosure focuses on voltage and current clamping with power recovery in matching networks and other embodiments, further disclosure regarding the structure, architecture, function, and algorithms of matching networks may be found, for example, in commonly assigned U.S. Pat. No. 9,660,613, which is incorporated herein by reference in its entirety. In FIG. 4B, the RF matching network system 401 includes a voltage clamp 403, which includes a rectifier module 454 and a power converter 460. The rectifier module 454 is implemented inside the matching network 430 in this embodiment. FIG. 4B illustrates the use of a voltage clamp 403 with power recovery to limit the voltage at the protection node 440 relative to the reference node 452, thereby protecting the matching network 430 from overvoltages.That is, the voltage clamp 403 is embodied to limit the voltage or another selected voltage component within the matching network 430 and to protect the matching network 430 as its protection device, similar to the architectural and functional relationships between the voltage clamps and corresponding protection devices in other embodiments disclosed herein.

[0083] In particular, the voltage clamp 403 is connected to the parallel switched capacitor 434 of the matching network 430 and the switched capacitor array 409 of the switch 436 via the protection node 440 and the reference node 452. The voltage clamp 403 thereby protects the switched capacitor array 409 as a protection device of the voltage clamp 403, similar to that described above with respect to the protection device 111 in the embodiment of FIG. 1C. That is, the voltage clamp 403, which includes the rectifier module 454 and the power converter 460, may protect the switched capacitor array 409 as its protection device in the RF matching network system 401. The RF matching network system 401 of FIG. 4B, which excludes the RF generator 432, may be an exemplary implementation of the RF load 414 of FIG. 4A. The power converter 460 incorporates a structure similar to the exemplary power converter of FIG. 3E as described above. The power converter 460 is configured to deliver its recovered power to a power sink in the form of a single-phase AC utility source, such as AC utility source 466, in this embodiment. The power converter 460 is connected to the AC utility source 466 in order to use the AC utility source 466 as a power sink, with the power converter 460 being isolated from the input to the power converter 460 to deliver the power recovered from the voltage clamped by the voltage clamp 403. In this manner, the voltage clamp 403, in this embodiment, is able to successfully recover and reuse the power recovered as a result of clamping the voltage, and to sustain the voltage clamping for as long as necessary, as opposed to being limited to short-term voltage clamping constrained by the capacity of resistors, semiconductor devices, or other circuit elements to absorb excess power from the voltage clamping. The power converter 460 may be connected to the power source of the RF generator 432 or any other type of power sink, such as a DC rail or DC power supply, in other embodiments.

[0084] The matching network 430 includes a controller 450 that controls the switch 436 to rapidly connect and disconnect the capacitor 434 to and from the network in response to changing load impedance conditions at the RF load 448 to maintain the impedance match of the matching network 430 with the changing impedance of the load. The matching network 430 may also contain fixed components, such as an inductor 438. The switched capacitor arrays 409 and 411 may also include fixed components, such as those implementing part or all of the inductor 438, or have components connected between the nodes 440 and 452, and the nodes 451 and 452, respectively, that are not switched in and out of the circuit by the switch 436. Without the voltage clamp 403, sudden changes in the characteristics of the RF load 448, which may be a plasma load, during operation of the circuit may cause an overvoltage condition of the protection node 440 relative to the reference node 452. The reference node 452 in this embodiment is also equivalent to a control voltage reference node as described above, since it is electrically coupled by a simple conductive line across the low voltage side of the rectifier module 454 and to the power converter 460, as shown in FIG. 4B. The rectifier module 454 of the voltage clamp 403 includes a diode 456 and a capacitor 446. The rectifier module 454 is connected to the power converter 460. Similar to the power converter of FIG. 3E, the power converter 460 may include an input capacitor 462, and a controller 468 of the power converter 460 operates the switches of the power converter 460 to maintain a constant voltage between the control voltage node 442 and the reference node 452 that is below a desired clamping voltage by the amount of the voltage drop across the single diode 456 of the rectifier module 454, and to divert and recover excess power to an AC power source, such as an AC utility supply 466. In other embodiments, the rectifier module 454 may include multiple diodes and the power converter 460 may maintain a constant voltage between the control voltage node 442 and the reference node 452 that is below the desired clamping voltage by the amount of voltage drop across the multiple diodes of the rectifier module 454.The controller 468 may also control the circuitry to transfer power only to a single phase of the AC utility source 466. In particular, the controller 468 may control the eight switches shown in the power converter 460, four on each side of the transformer, to deliver the recovered power to the single-phase AC utility source 466. Through operation of the controller 468, the power converter 460 and the voltage clamp 403 as a whole may thereby recover power from the operation of the RF matching network system 401 and usefully return it to the AC utility source 466. The controllers 450 and 468 may be implemented in the same hardware, such as a single controller module, or inside the same FPGA, or in executable code executed with the same microprocessor, to name a few of many possible implementations. In other embodiments, the power converter may be configured to deliver the recovered power to another type of power sink, such as a three-phase AC power source, a DC rail, or a DC power supply.

[0085] The matching network 430 may thus, in various embodiments, include an input terminal, an output terminal, an impedance matching network coupled to the input terminal and the output terminal and configured to perform impedance matching with a load coupled to the output terminal, a rectifier module coupled to the matching network, and a power converter coupled to the rectifier module. The matching network 430 may, in various embodiments, be configured to respond to a voltage component reaching a voltage component limit by diverting power to the power converter, thereby limiting the voltage component. The power converter may, in various embodiments, be configured to output at least a portion of the power to a power sink. The matching network 430 may thus, in various embodiments, be responsive to a voltage component of the voltage in the matching network reaching a voltage component limit by diverting power from the matching network, through the rectifier module, to the power converter, thereby limiting the voltage component in the matching network, and outputting power from the power converter to the power sink. The voltage component limit may be or include a voltage limit, and responding to the voltage component of the voltage in the matching network reaching the voltage component limit may, in various embodiments, include responding to the voltage in the matching network reaching the voltage limit by diverting power from the matching network, through the rectifier module, to the power converter, thereby limiting the voltage in the matching network. The matching network 430, in various embodiments, may output power from the power converter to the AC power source.

[0086] In another exemplary embodiment, the implementations of Figures 4A and 4B may be combined together such that the RF matching network system 401 of Figure 4B may function as the RF load 414 of Figure 4A and the RF generator 400 of Figure 4A may function as the RF generator 432 of Figure 4B. In such an embodiment, two separate voltage clamps with power recovery may thus clamp voltage and recover power in two different subsystems of the overall system, with the voltage clamp 407 of the RF generator 400 functioning as a first voltage clamp to recover the voltage clamped RF generator power to the DC power supply 406 and the voltage clamp 403 of the RF matching network system 401 functioning as a second voltage clamp to recover the voltage clamped matching network power to the DC power supply 406 rather than the AC utility supply 466. An example of this is disclosed in Figure 4C.

[0087] 4C depicts an RF generator system 470 in another exemplary embodiment that may be contained within a single RF generator enclosure and includes an integrated matching network 472 integrated with the generator, a first voltage clamp 471 for clamping the voltage around a power device 473 as a protection device, and a second voltage clamp 474 for clamping the voltage around a switched capacitor array 475 of the integrated matching network 472, all integrated within a single RF generator system 470 that recovers power from the voltage clamping and delivers the recovered power to a DC power supply 476. The enclosure may exclude an RF load 499, as may be the case with an integrated generator and matching network connected to a plasma chamber, or may include an RF load, as may be the case with a remote plasma source. The first voltage clamp 471 includes a first rectifier module 478 and a first power converter 479, similar to the various embodiments discussed above, and clamps the voltage at the protection node 491 to a reference node 492, thereby clamping the voltage across the power device 473. The second voltage clamp 474 includes a second rectifier module 481 and a second power converter 482, similar to the various embodiments discussed above, and clamps the voltage at the protection node 493 to a reference node 494, thereby clamping the voltage on the switched capacitor array 475. In this embodiment, a single controller 490 may control the power device 473, the switches 483 of the switched capacitor array 475, the switches 477 of the first power converter 479, and the switches 480 of the second power converter 482, thereby controlling the voltage clamping and power recovery functions of the RF generator system 470. In other embodiments, multiple controllers may be implemented and may have different control functions of the RF generator system 470 divided among them, including control of the DC source 476. The RF generator system 470 provides RF power to an RF load 499, such as a plasma chamber.First voltage clamp 471 and second voltage clamp 474 are each configured to recover power from clamping any excess voltage in their respective applications and divert that power to rail 484 and DC power supply 476. Rail 484 and DC power supply 476 thus act as a single common power recovery sink for both voltage clamps 471, 474 in this embodiment.

[0088] The RF generator system 470 may also be considered and referred to simply as a generator, with the understanding that in this embodiment the generator includes a matching network. In other embodiments, the generator may be implemented with a voltage clamp to clamp the voltage on any of the various selected nodes in the generator's circuitry, rather than clamping the voltage on a power device or other protection device. In such embodiments, the voltage clamp or clamps on one or more internal nodes in the generator's circuitry may also be configured to recover power from the voltage clamping to a useful power sink, such as a DC rail, a DC power supply, or an AC power supply.

[0089] 5A and 5B show a series stacked switch circuit 501, 547 including an implementation of a voltage clamp with power recovery according to different embodiments of the present disclosure. A series stacked switch circuit can be used to create a high voltage switch using multiple lower voltage switches stacked in series. For example, stacking 10 switches in series, each switch capable of safely handling 1 kV across each individual switch, creates a switch capable of handling 10 kV across the entire stack, provided that the voltage across each individual switch is limited to 1 kV or less. Other examples may include any other number of switches with any feasible values ​​for safe voltage limits across each switch. The stacked switch circuit 501, 547 may provide fine tuning control of the power delivered to specialized loads, such as to control desired values ​​of average ion energy and ion energy distribution width at the plasma sheath in a plasma reactor to achieve desired properties in material processing. This may be in the context of mid-frequency (e.g., hundreds of kilohertz), pulsed DC, and / or electron volt (eV) sources, high power electron volt (HOeV) sources, or HOeV-like generators (which may be collectively referred to as eV-type or eV-like generators) in some examples. Further details regarding HOeV-like generators in various embodiments are disclosed in co-pending patent application Ser. No. 16 / 926,867, the entirety of which is incorporated herein by reference. In different embodiments, the HOeV-like generator may incorporate one or more stacked switch circuits in the embodiments of stacked switch circuits 501 and / or 547.

[0090] One problem that can arise in a series stacked switch circuit is that the voltage across an individual switch in the stack may exceed the voltage that an individual switch can handle, potentially causing the individual switch to fail. Consider the example of a 5 kV voltage source connected across a series combination of five switches and a load (e.g., a resistor in series with an inductor). When all the switches are closed, current flows through the switches and the load, and assuming the on-state resistance of each switch is small compared to the load impedance, the voltage across each switch will be close to 0 V. Now consider the problem of opening the switches to stop the flow of current. It is very difficult to perfectly control the switches so that they all open at the same time. Consider the case where the current through the switches is 200 A and one of the switches opens 10 nanoseconds before the rest. If the load is inductive, it will be very likely that the current will remain close to 200 A for 10 nanoseconds. The increased switch resistance in the off state will likely cause the voltage across the switches to rise to the breakdown voltage of the switches. Assuming the breakdown voltage of the switch is 1,200V, then for a period of 10 nanoseconds the switch will both have 1,200V across it (typically the switch will be in avalanche mode) and will be conducting 200A through it. A current of 200A is in itself large enough to cause a typical MOSFET switch to fail through secondary breakdown, but even if this does not happen, the energy the switch absorbs during this time will be 2.4mJ. If this happens at a 400kHz rate, the dissipation in the switch will be 960W, which is higher than a typical MOSFET can safely dissipate.

[0091] The stacked switch circuit 501 of FIG. 5A protects individual switches in a series stacked switch from overvoltage without the need to dissipate power that would result from clamping the voltage across an individual switch. As an example where an optional capacitor 506 is used, assume that the power converter 502 maintains the voltage across the capacitor 506 at 990V by diverting power to the power sink 504 whenever the voltage across the capacitor 506 begins to rise above 990V. The operation of the circuit can be understood by considering the above example as it relates to the switch 530 between nodes 523 and 525 of the stacked switch circuit 501. That is, assume that the stacked switch circuit 501 in series with a load (not shown in FIG. 5A) is connected across a 5 kV supply and that the stacked switch circuit 501 is conducting 200A through the switch 501 and the load with the stacked switch circuit 501 in the on state. With all individual switches configured in stacked switch circuit 501 on, current flows from upper node 508 through switch 520, switch 530, any switches represented by ellipsis, switch 537, and switch 540 to lower node 546. Now consider switch 530, which opens 10 nanoseconds earlier than the remaining switches in switch circuit 501. With switch 530 open (off) and the remaining individual switches still closed (on), current flows from upper node 508, through switch 520, through diode 531, capacitor 533, any switches represented by ellipsis, switch 537, and switch 540 to lower node 546. That is, the current that was flowing and would have continued to flow through switch 530, if it had still remained closed in perfect time with the other switches, now flows instead through diode 531 and capacitor 533. As shown below, the voltage across capacitor 533 at the time the switch is open, i.e., the voltage at node 527 relative to node 525, is approximately 991.4 V, assuming all diode voltage drops are 0.7 V. Assume the capacitance value of capacitor 533 is 1 μF.At the end of the 10 nanosecond period, the voltage across capacitor 533 rises to 993.4V, assuming the current remains at 200A for the entire 10 nanoseconds in which switch 530 is the only individual switch that is open. This means that the voltage across switch 530 is limited to 994.1V, assuming the voltage drop across diode 531 is 0.7V. When the remaining individual switches are closed, capacitor 533 discharges through diode 532, optional element 534, diode 510, optional element 512, capacitor 506, switch 520, and switch 530. Assuming that optional elements 534 and 512 are simple resistors that limit the peak discharge current, and that switches 520 and 530 also act like low value resistors when closed / on, capacitor 533 will discharge to the voltage across capacitor 506 plus two diode voltage drops, i.e., capacitor 533 will discharge to a voltage of 991.4V. The same mechanism protects all of the individual switches configured in stacked switch circuit 501 against overvoltage. The clamping voltage increases slightly for each switch as you move toward lower node 546. For example, with the same assumptions (200A, 1 μF capacitor, 10 nanosecond delay, 0.7V diode drop, capacitor 506 voltage maintained at 990V, element G being a simple resistor), the voltage across switch 520 is limited to 993.4V, and if there are a total of 10 individual switches configured in stacked switch circuit 501 (i.e., the ellipses represent an additional 6 switches), switch 537 will be clamped to 999V and switch 540 to 999.7V. The total voltage across stacked switch circuit 501 will be clamped to 9,945.5V at the start of an overvoltage event in this case. If the current through stacked switch circuit 501 during an overvoltage event is 200A and lasts for 10 nanoseconds, the total voltage across switch 501 will rise to 9,965.5V.Although clamping the voltage across the stacked switch circuit 501 (i.e., the voltage at the upper node 508 relative to the lower node 546) is part of what the stacked switch circuit 501 does, typically and more often than not, the stacked switch circuit 501 functions to protect the individual switches configured in series within the stacked switch circuit 501 from overvoltage rather than limiting the voltage at node 508 relative to node 546. The stacked switch circuit 501 relies on the periodic closing (turning on) of the stacked switch circuit 501. It is during the switch on (closed) time that the capacitors 522, 533, etc. discharge through the capacitor 506. Without the periodic closing of the stacked switch circuit 501, the stacked switch circuit 501 would not function as intended. Fortunately, most applications requiring series stacked switches are used in a manner that ensures the periodic closing of the stacked switch circuit 501.

[0092] 5A, various aspects of a connecting circuit 509, which comprises multiple switch modules in a switch module series stack 513, a power converter 502, and a series diode stack connecting the switch modules to the power converter 502, function together to clamp the voltage across each switch module in the switch module series stack 513. In FIG. 5A, the stacked switch circuit 501 includes several individual discrete switches, of which switches 520, 530, 537, and 540 are labeled, which are connected to a voltage V H at the upper node 508 and the voltage V L 5 and a lower node 546 in a switch module series stack 513, ie, a stack of switch modules connected in series.

[0093] During normal operation of the switches, the upper node 508 is at a higher voltage than the lower node 546 for at least a portion of the time that the switches are all open, and the upper node voltage V H is essentially the lower node voltage V LEach switch in the stacked switch circuit 501 is positioned between its own respective local high-side or guard node and a local low-side or reference node, and in parallel with its own local rectifier and local capacitor, which together form its own local switch module. For example, switch 520 is directly coupled between a local high-side node 518 (i.e., a node on the local high-voltage side relative to the switch 520, structured and functioning as a guard node, which may be similar to a guard node as described above) and a local low-side node 526 (i.e., a node on the local low-voltage side relative to the switch 520, structured and functioning as a reference node, which may be similar to a reference node as described above), and in parallel with its own local diode 514 (acting as a rectifier) ​​and its own local capacitor 522, forming a local switch module 515. The local switch module 515 thus comprises the switch 520, the diode 514, and the capacitor 522. Each subsequent discrete switch in the switch module series stack 513 between the upper node 508 and the lower node 546 similarly forms part of its own switch module with its own local rectifier and capacitor, similar to the arrangement of local switch modules 515, of which depicted examples include local switch modules 529, 535, and 539. In other embodiments, the switch modules may include switches and rectifiers and omit the capacitors, may include more than one diode as shown, or any other type of rectifier network other than or including diodes, and may also include other circuit elements (e.g., one or more resistors, one or more inductors).

[0094] An ellipsis is depicted between local switch modules 529 and 535 to indicate that any number of additional local switch modules may also be included in the switch module series stack 513 in the intervening space. Various embodiments may include any number of local switch modules in the switch module series stack 513, including embodiments with only the four switch modules depicted, or fewer.

[0095] Each local switch module in the switch module series stack 513 includes a diode and a capacitor coupled in series with each other between the high-side and low-side nodes of the local switch module and in parallel to the local switch of the switch module, where the diode acts as a local rectifier. As a specific example, in local switch module 515, a diode 514 (acting as a rectifier) ​​and a capacitor 522 are coupled together in series between a local high-side node 518 and a local low-side node 526, and in parallel to a local switch 520. In this case, the local low-side node 526 is structured and functions as a reference node as described herein for the switch module 515, and the switch 520 is directly coupled to a control voltage reference node 528 for the adjacent local switch module 529 and switch 530. The stacked switch circuit 501 may maintain the voltage across the capacitor 522 between the control voltage node 516 and the control voltage reference node 528 of the switch module 515 local to the switch 520 at or within a desired local clamping voltage for the local switch module 515. The global voltage clamping of the stacked switch circuit 501 may involve an accumulation of the local voltage clamping across each of the local switch modules in a series of stacked local switch modules.

[0096] The stacked switch circuit 501 is thus configured to clamp or limit the voltage on itself, i.e., on the stacked switch circuit 501. A stacked switch circuit 501 configured to limit a voltage on itself comprises a stacked switch circuit 501 configured to limit a voltage or a component of a voltage between an upper node 508 and a lower node 546. A stacked switch circuit 501 configured to limit a voltage on itself, or between an upper node 508 and a lower node 546, may include a stacked switch circuit 501 configured to clamp or limit a voltage on each of the switch modules configured in the stacked switch circuit 501, which may include clamping or limiting a voltage between an individual high or protection node and an individual low or reference node on the individual switch modules. The stacked switch circuit 501 may be configured to clamp or limit the voltage across an individual switch module at a maximum or limit voltage, which may be equal to the sum of the nominal maximum voltage of the individual capacitor and the nominal voltage drop across the individual diode or other rectifier of the individual switch module. The clamping voltage may be set below the limiting voltage of the switch, for example the drain-source breakdown voltage of the MOSFET implementing the switch.

[0097] The power converter 502 is coupled between an upper node 508 and a connection circuit 509 comprising a series stack of diodes, of which diodes 510, 532, 538, and 542 are labeled. The connection circuit 509 may include any number of diodes connected in series to correspond to the number of local switch modules in the switch module series stack. Each diode in the series stack in the connection circuit 509 is coupled to a node in the corresponding switch module between the diode and a capacitor of that switch module (which may be referred to as the control voltage node of the switch module) either directly, as illustrated with diodes 510, 532, and 538, or indirectly, as illustrated with diode 542 connecting through optional element 543. The capacitor of the switch module is connected to the power converter 502 through the connection circuit 509, either directly or indirectly, depending on whether and what type of optional circuit element G may be included in the connection circuit 509. The optional circuit element G may connect both sides of a diode in the connection circuit. Optional elements 512, 534, 536 are shown between the diode and the power converter, but optional elements G A 543 and G B As illustrated for switch module 539 with 544, the connection circuit 509 may be between the rectifier and the diode. The connection circuit 509 may thus function as a power converter connection circuit, connecting the switch module series stack 513 with the power converter 502. In some embodiments, the connection circuit 509 may also function as part of a distributed power converter (as discussed further below). Depending on the implementation of the connection circuit 509, current may flow from the capacitors of the switch modules, through the control voltage nodes of each switch module (e.g., the capacitor 522 and control voltage node 516 of the switch module 515 local to and associated with the switch 520), through the connection circuit 509 (and through optional elements G in the connection circuit 509, if included) to the power converter 502.

[0098] The power converter 502, in the context of current flow from the local switch module of the connection circuit 509 under the control of the controller 503, may usefully recover power from the voltage clamping and divert the recovered power to the power sink 504 for subsequent use. The power sink 504 may, in different examples, be an AC power source, a DC power source, a DC rail, a rechargeable battery, a power reservoir, or another component or system to which the recovered power may be usefully restored. Any of these or other types of power sinks that are also enabled to provide power may, in various embodiments, be considered a power source to which the switch circuit recovers power. The various components of the stacked switch circuit 501 may thus cooperate to act as a voltage clamp and recover power from the voltage clamping to the power sink 504 via the power recovery output node 505, rather than having to dissipate the voltage clamping power by diverting excess power from the voltage clamping to a dissipative element (e.g., a Zener diode, a MOSFET, or a resistor) and relying on losing the power to waste heat.

[0099] The connection circuit 509 is thus coupled to the switch modules of the stacked switch circuit 501. In this embodiment, the connection circuit 509 is coupled to each individual one of the switch modules at the individual switch module's node between the individual switch module's rectifier and the capacitor. Each individual one of the series stacked diodes in the connection circuit 509 is coupled to a corresponding individual one of the switch modules at the individual switch module's node between the individual switch module's rectifier and the capacitor.

[0100] Figures 5C, 5D, 5E, 5F, and 5G depict various example circuit elements that may be used to implement each optional circuit element G of Figures 5A and 5B in different embodiments. As shown in Figures 5A and 5B, diodes that are part of connection circuit 509, including diodes 510, 532, 538, and 542, can be placed in series with optional circuit element G, of which optional circuit elements 512, 534, 536, 544, and 543 are labeled. These optional elements may be, for example, a short circuit as illustratively depicted in the embodiment of Fig. 5C (i.e., there is no optional element G other than the conductive line provided), a switch as illustratively depicted in the embodiments of Fig. 5D and Fig. 5G, a resistor as illustratively depicted in the embodiment of Fig. 5E, an inductor as illustratively shown in the embodiment of Fig. 5F, or a multi-element circuit (which may include, for example, a switch, an inductor, one or more diodes) as illustratively shown in the embodiment of Fig. 5G, to name a few. The various optional elements G, when implemented, may allow the converter to maintain a constant input voltage or, in the case when optional capacitor 506 is provided, limit the peak current through diodes 510, 532, 538, and 542 when switches 520, 530, and 540 are closed. When optional element G is a switch, the switch can be closed (under control of controller 503) when the voltage between the control voltage node and the control voltage reference node of the corresponding switch 520, 530, or 540 exceeds a threshold voltage. In this case, power converter 502 can be embodied generally similarly to step-down converter 301 of FIG. 3A, except that input capacitor 306 and switch 302 can be eliminated, for example, because their functions can be performed instead by local capacitors (of which capacitor 522 is an example) connected between the local control voltage node and the local control voltage reference node of each switch module, and / or by a local switch implementation of optional circuit element G (of which optional circuit element 512 is an example).

[0101] The power converter 502 may thus direct the recovered power to the power sink 504. In the embodiment of FIG. 5A, the voltage across each local switch module in the stacked switch circuit 501 to which the voltage is clamped increases by one diode voltage drop across each local switch module from the switch module 515 closest to the upper node 508 and the power converter 502 to the switch module 539 furthest from the power converter 502. This increase in clamping voltage across a series of local switch modules is acceptable in many contexts, provided that the desired clamping voltage is typically significantly higher or may be much higher (e.g., 20V, 120V, 900V) than a typical diode voltage drop (e.g., 1V). In other examples, the desired clamping voltage and diode voltage drop values ​​may be any other of a wide range of values. Because the local capacitors associated with each individual switch in the local switch module (e.g., capacitor 522 associated with switch 520) absorb charge when the switch is off and the voltage across the stacked switch circuit 501 is higher than the capacitor voltage and the diode drop voltage and discharges only through the power converter 502 (and optional capacitor 506, if included) once a switch is closed in the series of switch modules, the individual local capacitors can be large enough to absorb charge without the capacitor voltage exceeding the desired clamping voltage. The power converter 502 and / or connection circuitry 509 under the control of the controller 503 may also, in various embodiments, act in response to any voltage rise in the switch module series stack 513 that might otherwise rise above the desired clamping voltage by diverting any power recovered from voltage clamping from the series of stacked switch circuits 501 of the switch modules via the power converter 502 to the power sink 504 for useful power recovery. The stacked switch circuit 501 is therefore configured to limit the voltage or a component of the voltage within the stacked switch circuit 501 and recover power from the limiting of the voltage.

[0102] As shown in FIG. 5B, the stacked switch circuit 547 with a voltage clamp with power recovery shown in FIG. 5B, in this case, the power converter 596 is different from that between the upper node 508 and the common node 524 of FIG. 5A. It is somewhat similar to the stacked switch circuit 501 shown in FIG. 5A, except that it is disposed between the lower node 594 at voltage V L and the common power converter input node 588. In FIG. 5B, some of the switches, among which switches 562, 570, 576, and 584 are labeled, are connected in a switch module series stack 563 between the upper node 552 at voltage V H and the lower node 594 at voltage V L . The stacked switch circuit 547 may also include an optional capacitor 590. During the normal operation of the switches, the upper node 552 is at a voltage higher than the lower node 594 during at least a part of the time when all the switches are open, and the upper node 552 is essentially at the same voltage as the lower node 594 when all the switches are closed. Each switch is associated with a local protection node (e.g., the local protection node 554 local to switch 562) and a local reference node (e.g., the local reference node 568 local to switch 562) in its own local switch module. In the local switch module for switch 562, a local diode acting as a rectifier, that is, in the case of the local switch module of switch 562, a single local diode 548 connects the local protection node 554 and the local reference node 568 to a local capacitor 556 that is connected between the local control voltage node 550 and the local control voltage reference node 560. In this case, the local protection node 554 is the same as the local control voltage node 550, that is, in direct conductive contact with it.

[0103] The stacked switch circuit 547 may, for example, maintain a desired local clamping voltage in each local switch module between the local control voltage node 550 and the control voltage reference node 560. A power converter 596 is connected between the local switch modules of the switch module series stack 563 and a lower node 594 of the stacked switch circuit 547 via a series diode stack 559, of which exemplary diodes 558, 572, 578, and 586 are labeled, and a common power converter input node 588. The capacitors of the switch modules are connected to the power converter 596 via the series diode stack 559, either directly or indirectly, depending on whether and the type of optional circuit element G may be included in the series diode stack 559. The series diode stack 559 may thus function as a power converter connection circuit, connecting the switch module series stack 563 with the power converter 596. In some embodiments, the series diode stack 559 may also function as part of a distributed power converter (as discussed further below). Depending on the implementation of the series diode stack 559, current may flow from the capacitor of the switch module, through a control voltage reference node of each switch module (e.g., the switch module's local capacitor 556 and local control voltage reference node 560 local to switch 562) as opposed to a control voltage node as in FIG. 5A, through the series diode stack 559 (and through optional element G in the series diode stack 559, if included) to the power converter 596. The power converter 596 in the context of current flow from the local switch module of the series diode stack 559 under the control of the controller 597 may usefully recover power from voltage clamping and divert the recovered power to the power sink 592 for subsequent use. The power sink 592 may, in different embodiments, be an AC power source, a DC power source, a DC rail, a rechargeable battery, a power reservoir, or another component or system to which the recovered power may be usefully restored.The various components of the stacked switch circuit 547 may therefore cooperate to act as a voltage clamp and recover power from the voltage clamping to a power sink 592 via a power recovery output node 595, rather than having to rely on dissipating the voltage clamping power from a capacitor or diverting excess power from the voltage clamping to a capacitor or other dissipative element and losing the power to waste heat.

[0104] The series diode stack 559 forms a connection circuit between the switch module series stack 563 and the power converter 596. The diodes that are part of the series diode stack 559, including the illustratively depicted diodes 558, 572, 578, and 586, can be placed in series with optional circuit elements G (of which optional circuit elements 564, 574, 580, and 582 are labeled). These optional circuit elements can be, for example, short circuits (i.e., no optional element G is provided) as shown in FIGS. 5C, 5D, 5E, and 5F, respectively, to name a few, switches, resistors, or inductors, or other circuit elements in other embodiments. When provided, the optional circuit element G can limit or modify the peak voltage and / or current through the diodes 558, 572, 578, and 586. In embodiments where optional circuit elements G are switches, these switches can be closed when the voltage between the local control voltage node and the local control voltage reference node of the corresponding switch 562, 570 or 576, or 584, for example, exceeds a selected voltage clamping threshold. In this case, the power converter 596 can be implemented in an embodiment similar to the buck converter of FIG. 3A, although the input capacitor 306 and switch 302 can be omitted, for example, because their functions can be implemented by a local capacitor (of which local capacitor 556 is an example for switch 562) connected between the local control voltage node and the local control voltage reference node of each switch, and optional circuit elements G implemented as switches (of which optional circuit element 564 is an example).

[0105] The power converter 596 may direct any excess power from the voltage clamping to a power sink 592 via a power recovery output node 595, thereby implementing useful recovery of power from the voltage clamping. In this embodiment, the voltage across the switches in the switch modules to which the voltage is clamped may be increased by one diode drop per each local switch module between the switch 584 closest to the power converter 596 and the switch 562 furthest from the power converter. This may provide effective voltage clamping across a series switch circuit in many contexts, provided that the desired clamping voltage may typically be much higher (e.g., 900V) than a typical diode voltage drop (e.g., 1V) as an illustrative example. The desired clamping voltage and diode voltage drop may also take any other value, higher or lower than these values, in other embodiments, depending on the design goals and implementation details being embodied. 5A or 547 as in FIG. 5B may be implemented with any of a wide variety of diodes having any of a wide variety of drop voltages and any of a wide variety of optional switch elements, as well as any of a wide variety of other area options, allowing for a variety of flexible implementations that may provide voltage clamping with power recovery optimized for any of a variety of contexts and applications. The stacked switch circuit 547 is thus configured to limit the voltage or a component of the voltage within the stacked switch circuit 501 and recover power from the voltage limit.

[0106] The stacked switch circuits 501, 547 of Figures 5A, 5B in any of various implementations may thus function as an embodiment of a voltage clamp with power recovery for a plurality of series-connected switches. The stacked switch circuits 501, 547 with voltage clamping each include a plurality of switches connected in series between two terminal nodes, each having a first and second local node, with an upper node and a lower node. The first local node of the first switch is connected to the upper node of the respective stacked switch circuit, the first local node of each successive switch of the plurality of switches is connected to the second local node of the preceding switch of the plurality of switches, and the second local node of the last switch is connected to the lower node of the respective stacked switch circuit. Each of these stacked switch circuits further includes a plurality of capacitors, of which each local capacitor of a local switch module is associated with a corresponding local one of the switches. Each of these stacked switch circuits further includes a plurality of rectifiers, each of which is associated with a respective local switch of the plurality of switches in such a manner that the voltage difference between the two local nodes of the respective switch is limited to the sum of the capacitor voltage of the respective local capacitor and the rectifier voltage drop of the respective local rectifier, and each rectifier connects the two local nodes of the respective switch to a respective local capacitor of the plurality of capacitors associated with or local to the switch of the corresponding local switch module. Each of these stacked switch circuits 501, 547 further includes a power converter (e.g., power converter 502 in FIG. 5A, power converter 596 in FIG. 5B). Each of these stacked switch circuits 501, 547 further includes a circuit comprising at least one diode, the power converter being directly or indirectly coupled to the capacitor with the circuit and to at least one of the upper node and the lower node.Each of these stacked switch circuits further includes one or more output nodes (power recovery output node 505 in FIG. 5A , power recovery output node 595 in FIG. 5B ) coupled to a power converter (power converter 502, 596, respectively) and configured to couple to a power sink (power sink 504, 592, respectively), and the circuit and power converter are configured to reduce or maintain the voltage of a capacitor associated with the switch at or below a desired clamping voltage when the switch is closed, and recover voltage clamping power, by outputting power via the one or more output nodes.

[0107] Thus, the stacked switch circuits 501, 547 are examples of switch circuits including two terminal nodes (e.g., in these embodiments, an upper node and a lower node), multiple switch modules, a connection circuit, and a power converter. In these examples, the switch modules are connected in series between the upper node and the lower node. In these examples, each switch module in the switch circuit includes a switch, a rectifier, and a capacitor. The connection circuit is coupled to the switch module. The power converter is directly or indirectly coupled to the connection circuit and to one of the terminal nodes. In this context, an indirect connection may involve connecting the power converter to one of the terminal nodes through a circuit that may include other components such as resistors, capacitors, or diodes, to name a few. That is, the power converter is coupled to the connection circuit and either to the upper node (e.g., as in FIG. 5A) or the lower node (e.g., as in FIG. 5B). The switch circuit is configured to output recovered power from the switch module to and from the power converter via the connection circuit to a power sink coupled to the power converter. The switch circuit thereby limits the voltage within the switch circuit between the upper and lower nodes (or elsewhere on the switch circuit), for example across each switch module, and recovers power from the voltage limitation to a power sink.

[0108] FIG. 6A illustrates a high-side stacked switch 610 (S 10 ), which is two stacked switches arranged in a high and low voltage side in a half-bridge configuration, in accordance with an embodiment of the present disclosure. H ) and low-side stack switch 616(S L 6 shows a stacked switch circuit 601 with a plurality of individual local discrete switches. The stacked switches 610 and 616 each comprise a stack of individual local discrete switches, e.g., the high-side stacked switch 610 comprises exemplary local discrete switches 603, 605, 609, 611, and the low-side stacked switch 616 comprises exemplary local discrete switches 621, 623, 631, 633. In different embodiments, the high-side and low-side stacked switches 610 and 616 may each include a wide variety of numbers of individual discrete switches, each with their own local modules of associated circuit elements (e.g., local capacitors and diodes). The stacked switches 610 and 616 may each comprise any number of individual local discrete switches in different embodiments. The local discrete switches are associated with their own local diodes that act as rectifiers and, together with the power converter 604, form a distributed implementation of a voltage clamp with power recovery. That is, the local diode rectifiers configured in the high-side stacked switch 610 and / or the low-side stacked switch 616, together with the power converter 604, may act as voltage clamps that may return power to the DC power supply 608. H ) is the high voltage (with respect to the lower node 618) V H The upper node 606 and the output node 614 (V out ) and a low-side stack switch 616 (S L ) is connected to the output node 614 and the low voltage (relative to the upper node 606) V L6. In some embodiments, the upper node 606 may have a particularly stabilized high-side voltage (e.g., connected to ground). In some embodiments, the lower node 618 may be connected to other circuitry or connected to a phase of an AC power supply. In some embodiments, the voltage at the upper node 606 may be more stable than the voltage at the lower node 618 such that it may be advantageous to have a power converter 604 connected directly to the upper node 606 and for the distributed voltage clamp of the stacked switch circuit 601 to perform voltage clamping and power recovery to the DC power supply 608 via the power converter 604 connected directly to the upper node 606.

[0109] A DC power supply 608 that powers the stacked switch circuit 601 is connected to the upper node 606 and the lower node 618 and acts as a power sink for the power converter 604. The output voltage V out The output node 614 with may be connected to another circuit or load, which may be a HOeV-like power source (as described above), as one example. The stacked switch circuit 601 may also include optional circuit elements G with their own local diodes, similar to similar structures as discussed above with reference to FIGS. 5A and 5B. The operation of the stacked switch circuit 601 may in various embodiments be similar in some ways to the operation of the stacked switch circuit 501 of FIG. 5A, except that instead of all switches being open and closed essentially simultaneously, or within a reasonably short time span, as in FIG. 5A, in various embodiments of the stacked switch circuit 601, the switches comprising the low-side switch 616 may be open and closed at the same time as each other, and the switches comprising the upper switch may be open and closed at the same time as each other, while the switches of the high-side stacked switch 610 and the low-side stacked switch 616, in various embodiments, may never be closed at the same time because under normal operation, that would short the upper node 606 to the lower node 618.

[0110] Figure 6A and C midA midpoint capacitor 612 local to a discrete switch 611 on the lower edge of the high-side stacked switch 610, also labeled as midpoint capacitor 612, is directly connected to the low-side stacked switch 616. When a discrete switch configured in the low-side stacked switch 616 is closed, current is steered through the midpoint capacitor 612 when any of the voltages across the capacitors local to the discrete switches of the low-side stacked switch 616 are higher than a desired clamping voltage. Because the midpoint capacitor 612 temporarily absorbs all the charge from the capacitors local to the local discrete switches of the low-side stacked switch 616 when any of their capacitor voltages exceed a desired clamping voltage, the midpoint capacitor 612 may be implemented to have a larger capacitance and handle higher ripple currents than other capacitors associated with other local discrete switches. When the local discrete switch associated with the high-side switch 610 is closed, current can flow through the power converter 604 and optional capacitor 602 if any of the voltages across the capacitors associated with the local discrete switches configured in the high-side stacked switch 610, including the midpoint capacitor 612, are higher than the desired clamping voltage.

[0111] In stacked switch circuit 601, each individual switch and each individual switch module is protected against overvoltage. As in Figures 5A and 5B, the switches closest to the power converter are limited to a slightly lower voltage than the switches further from the power converter. For example, if the voltage at the input of converter 604 is held at 990V, and the capacitors associated with each switch are large enough to limit the voltage rise while the switch is open to 2V, and all diode on-state voltage drops are assumed to be 0.7V, then switch 603 can be limited to 993.4V, assuming that elements G act like simple resistors (i.e., they do not cause additional voltage drops at low currents), and if there are a total of 20 switches in the stack, switch 663 can be limited to 993.4V, assuming that elements G act like simple resistors (i.e., they do not cause additional voltage drops at low currents), and switch 664 can be limited to 993.4V, assuming there are a total of 20 switches in the stack, and switch 665 can be limited to 993.4V, assuming there are a total of 20 switches in the stack, and switch 666 can be limited to 993.4V, assuming there are a total of 20 switches in the stack, and switch 667 can be limited to 993.4V, assuming there are a total of 20 switches in the stack, and switch 668 can be limited to 993.4V, assuming there are a total of 20 switches in the stack, and switch 669 can be limited to 993.4V, assuming there are a total of 20 switches in the stack, and switch 670 can be limited to 993.4V, assuming there are a total of 20 switches in the stack, and switch 672 can be limited to 993.4V, assuming there are a total of 20 switches in the stack, and switch 674 can be limited to 993.4V, assuming there are a total of mid 612 is C midAssuming that the voltage across V is large enough so that it does not rise significantly, it can be limited to 1,006.7 V. The circuit also H at the upper node 606 and the voltage V out It is possible to clamp the voltage between the output node 614 at out Node 614 in switch 610S H and V H less than the sum of the body diode voltage drops of the switches in L -(S L 616). Therefore, the body diodes will clamp V before the sum of the clamping voltages of each switch is exceeded. out It is highly likely that this will limit the voltage fluctuations.

[0112] FIG. 6B illustrates a high-side stacked switch 662 (S H ) and low-side stacking switch 664(S L6A ) and includes a distributed power converter that is not a discrete power converter but includes a distributed power converter switch 661 and, optionally, additional distributed power converter circuitry 674. In particular, the distributed power converter switch 661 is formed by a series of switches, including example switches 671, 672, 676, 677, 681, 682, 686, 687, connected between a capacitor associated with each switch module and a string of diodes that connect to the additional power converter circuitry 674 in some embodiments or to a DC power supply 658 or another power sink, and is under the control of a controller 655. In this embodiment, the controller 655 may control the distributed power converter switches 661 to be open and closed to collectively function as a power converter, without a discrete monolithic power converter 604 as in the embodiment of FIG. 6A , and, in some embodiments, optionally with the optional additional distributed power converter circuitry 674. The distributed power converter switch 677 associated with the midpoint capacitor 680 is closed when the low-side stack switch 664 is closed, and the capacitor C mid The capacitor associated with the low-side stacked switch 664 at a voltage above the voltage of 680 is the capacitor C mid 680. The distributed power converter switch 661 may close when a capacitor associated with the switch exceeds a desired clamping voltage. The distributed power converter switch 661 may be connected to an optional circuit element G as shown in FIG. 5A. A may be considered an embodiment of the present invention.

[0113] The high-side stacked switch 662 connects between the upper node 656 and the output node 654, and the low-side stacked switch 664 connects between the output node 654 and the lower node 668. A DC power supply 658 powers the stacked switch circuit 651 and connects to the upper node 656 and the lower node 668. The distributed voltage clamp of the stacked switch circuit 651 uses the DC power supply 658 as its power sink. The diode rectifiers of the local switch modules configured in the high-side and low-side stacked switches 662 and 664 and the distributed power converter switch 661 (optionally with optional additional distributed power converter circuitry 674) may thus together form another embodiment of a distributed voltage clamp with power recovery that may clamp voltage and direct recovered power from voltage clamping to the DC power supply 658.

[0114] FIG. 6B explicitly illustrates a stacked switch circuit similar to that of FIG. 6A in which the diode series stack comprises a switch that functions as part of a distributed power converter, although various embodiments of any of, or similar to, FIGS. 5A, 5B, 7, 8A, 8G, and 8H may also include a switch as an implementation of optional circuit element G as shown therein that may be included within a distributed power converter.

[0115] 7 shows a stacked switch circuit 701 with another arrangement of two stacked switches arranged in a half-bridge configuration with a voltage clamp with power recovery, according to another embodiment of the present disclosure. In contrast to the embodiment of FIG. 6A, in the stacked switch circuit 701, a power converter 716 and an optional capacitor 714 are connected to a lower node 712 rather than an upper node 702. A low-side stacked switch 710 (S L ) and high-side stacked switch 704(S H ) and a midpoint capacitor 708 (C mid) is local to a discrete switch 711 configured in and at the upper edge of the low-side stacked switch 710 that connects to the high-side stacked switch 704 in this embodiment. When the high-side stacked switch 704 is closed, if any of the voltages across the capacitors local to the discrete component switches configured in the high-side stacked switch 704 exceed a desired clamping voltage, current may flow temporarily through the midpoint capacitor 708, which may act as a temporary reservoir of charge before recovering the associated charge and associated energy to the power converter 716. When the low-side stacked switch 710 is closed, if any of the capacitor voltages associated with the discrete switches configured in the low-side stacked switch 710 exceed a desired clamping voltage, current may flow through the power converter 716 and optional capacitor 714. A controller 715 connects to and controls the power converter 716. The power converter 716 connects to a power sink 718, which may be a DC source as in FIG. 6A, which also connects to the upper node 702 (voltage V H at the lower node 712 (voltage V L The output node 706 (at the output voltage V out ) may be connected to other networks or loads.

[0116] 8A shows a stacked switch circuit 801 with yet another arrangement of a high-side stacked switch 808 and a low-side stacked switch 812 arranged in a half-bridge configuration with voltage clamping with power recovery, according to another embodiment of the disclosure. In this embodiment, the stacked switch circuit 801 includes two power converters 804 and 818, one at the upper node 806 (voltage V H at the lower node 814 (voltage V LA DC power source 820 is connected directly to both power converters 804, 818 and the upper and lower nodes 806, 814 to provide power to the stacked switch circuit 801. The power converters 804, 818 may cooperate with diode rectifiers in the local switch modules of the stacked switches 808, 812 to function as distributed voltage clamps with power recovery. Both power converters 804, 818 may use the DC power source 820 as a power recovery power sink, diverting power from the voltage clamping to the DC power source 820 for useful recovery. One or both power converters 804, 818 may have optional capacitors 802, 816 connected across the respective power converter inputs. The operation of the voltage clamp with power recovery associated with the high-side stacked switch 808 is similar to that of the voltage clamp with power recovery associated with the stacked switch circuit 501 of FIG. 5A, while the operation of the low-side stacked switch 812 is similar to that of the voltage clamp with power recovery associated with the stacked switch circuit 547 of FIG. 5B. The output node 810 of the half-bridge stacked switch circuit 801 (output voltage V out 6A, 6B, and 7 ) may be connected to other circuitry or loads. In various embodiments, the stacked switch circuit 801 may advantageously omit a relatively larger, higher capacitance capacitor at or near its half-bridge midpoint connected between the high-side and low-side stacked switches 808, 812, as in the embodiments of FIGS. 6A, 6B, and 7 , because any power recovered from voltage clamping on both sides of the stacked switch circuit 801 may flow to its own dedicated power converter on that side. That is, any power recovered from voltage clamping at the high-side stacked switch 808 may be directed to the power converter 804 on the high-voltage side of the stacked switch circuit 801, while any power recovered from voltage clamping at the low-side stacked switch 812 may be directed to the power converter 818 on the low-voltage side of the stacked switch circuit 801.

[0117] Thus, stacked switch circuits 601, 651, 701, and 801 of Figures 6A, 6B, 7, and 8A are further examples of switch circuits including two terminal nodes (i.e., in various embodiments, an upper node and a lower node), multiple switch modules, a power converter (i.e., at least one power converter), and a connection circuit connecting the switch modules to the at least one power converter. In these examples, as in the examples of Figures 5A and 5B, the switch modules are connected in series between the upper node and the lower node. In these examples, each switch module in the switch circuit includes a switch, a rectifier, and a capacitor. The connection circuit is coupled to the switch modules. At least one power converter is coupled to one of the connection circuit and the terminal nodes. That is, in embodiments with one power converter (e.g., the embodiment of Figs. 6A, 6B, 7, where the one power converter can be either discrete as in Figs. 6A and 7, or distributed as in Fig. 6B), the power converter is coupled to the connection circuit and at least one of the terminal nodes, e.g., either the upper node (e.g., as in Figs. 6A, 6B) or the lower node (e.g., as in Fig. 7). Other embodiments include multiple power converters, which may include a power converter coupled to both terminal nodes, as in the embodiment of Fig. 8A. At least one power converter may thus be connected to at least one of the terminal nodes and may be connected to both of the terminal nodes. The switch circuit may be configured to output recovered power from the switch module to and from the power converter via the connection circuit to a power sink coupled to the power converter. The switch circuit may thereby limit the voltage or other voltage component in the switch circuit and recover power from the voltage limit to the power sink. A "power converter" may include one or more discrete power converters and / or distributed power converter networks, as particularly discussed with reference to the embodiment of FIG. 6B and as may be applicable to various embodiments of any of FIGS. 5A, 5B, 6A, 7, and 8, as well as other embodiments.

[0118] The stacked switch circuits 601, 651, 701, 801 are therefore each configured to limit a voltage or a component of a voltage in the stacked switch circuit and recover power from the voltage limit. Each of these switch circuits may be further configured to limit a voltage across an individual switch module of one or more individual switch modules to a sum of a nominal capacitor voltage of a capacitor of the individual switch module and a rectifier voltage drop of a rectifier of the individual switch module. Each of these switch circuits may therefore also divert power from the switch module through a connection circuit coupled to the switch module to a power converter coupled to one of the connection circuit and the terminal node, thereby limiting a voltage or other voltage component in the switch circuit and recovering power from the voltage limit to a power sink, and recovering power may include transmitting, diverting, or outputting power from the power converter to the power sink.

[0119] In the embodiments of Figures 6A, 6B, 7, and 8, the switch circuit further includes a first stacked switch circuit, a second stacked switch circuit, and an output node. In the embodiments of Figures 6A, 6B, 7, and 8, the first stacked switch circuit constitutes a first portion of the switch module in the series stack (e.g., high-side stacked switch 610 of Figure 6A, high-side stacked switch 662 of Figure 6B, high-side stacked switch 704 of Figure 7, high-side stacked switch 808 of Figure 8A). The second stacked switch circuit constitutes a second portion of the switch module (e.g., low-side stacked switch 616 of Figure 6A, low-side stacked switch 664 of Figure 6B, low-side stacked switch 710 of Figure 7, low-side stacked switch 812 of Figure 8A). The output node is coupled between the first stacked switch circuit and the second stacked switch circuit (eg, output node 614 in FIG. 6A, output node 654 in FIG. 6B, output node 706 in FIG. 7, output node 810 in FIG. 8A).

[0120] 8B-8F depict various eV-like generators that may incorporate stacked switch circuits with voltage clamping and power recovery, according to various illustrative embodiments. eV-like generators may include HOeV generators, other eV generators, and other eV-like generators, and may be generally characterized as generators capable of providing pulsed DC power, generally at frequencies in the hundreds of kilohertz or low megahertz (and at energies that may be roughly on the order of magnitude of about 1,000 electron volts (eV)), to unstable loads, such as plasma chamber loads. eV-like generators may thus generally be applied to a variety of material processing applications (particularly as opposed to semiconductor processing), and may generally be distinguished from RF generators that are specialized to provide RF power (e.g., at frequencies between 100 kHz and 3 GHz), such as RF generator 400 and RF generator system 470 of FIGS. 4A and 4C, respectively. However, these general exemplary characteristics and distinctions are for various illustrative embodiments only and are not limiting in any way, as various embodiments of any of the embodiments disclosed herein may be broadly applicable to various other categories or types of generators or other applications, some of which may transcend or blur the boundaries of the general categories or descriptions provided as illustrative examples herein.

[0121] FIG. 8B shows an illustrative example generator 840A that includes a single switch 842 and a single voltage source, DC voltage supply 841, that functions as a power supply. The switch 842 of FIG. 8B may be implemented in various embodiments as an embodiment of stacked switch circuit 501 or 547 as shown in FIG. 5A, 5B and described above. FIG. 8C shows an illustrative generator 840B, which is a more detailed diagram of an illustrative implementation of generator 840A of FIG. 8B, in which switch 842 of FIG. 8B is implemented as switch 843 in a stacked switch circuit configuration. FIG. 8D shows an illustrative example generator 870A that includes two switches 872, 874 and two voltage sources, DC voltage supply 871 and DC rail voltage supply 873, each in a stacked switch circuit configuration. Switches 872, 874 as shown in Figure 8D may be implemented in the form of stacked switch circuits 501 and 547, respectively, as shown in Figures 5A and 5B, respectively. The addition of diodes 880 and 881 in Figure 8D, necessary for proper operation of the eV-like generator, generally makes the use of circuits 601, 651, 701, 801 as shown in Figures 6A, 6B, 7, and 8A, respectively, and described above less common for use in this particular implementation of an eV generator, but may be suitable for any application, depending on the particular design requirements of the eV-like generator. Figures 8E and 8F show example generators 870B and 870C, respectively, which are more detailed views of two illustrative implementations of generator 870A of Figure 8D. Generator 870B of Figure 8E shows an implementation of generator 870A of Figure 8D where switches 872, 874 of Figure 8D are implemented as switches 875 and 877, respectively, with power recovery from switches 875 and 877 to DC voltage supply 871. Generator 870C of Figure 8F shows an implementation of generator 870A of Figure 8D where switches 872, 874 of Figure 8D are implemented as switches 876 and 896, respectively, with power recovery from switches 876 and 896 to DC rail voltage supply 873.

[0122] 8B-8F, generators 840A, 840B, 870A, 870B, and 870C may be eV-like source generators that may allow fine control of the ion energy distribution (IED) properties of the plasma source powered by generators 840A, 840B, 870A, 870B, or 870C. For example, generators 840A, 840B, 870A, 870B, and 870C may allow fine control of IED properties such as the negative voltage level and flatness of the negative voltage pattern of the output voltage delivered via output nodes 848, 878 of generators 840A, 840B, 870A, 870B, and 870C, respectively, and thus to a load connected to the generators, such as plasma chambers 849, 879 (typically not part of the generators and therefore shown with dashed lines), which may be connected to output nodes 848, 878. In a plasma chamber 849 or 879 powered by generators 840A, 840B, 870A, 870B, or 870C, the negative voltage level may determine the average ion energy of the plasma, and the flatness of the negative voltage pattern may determine the ion energy distribution width of the plasma. In many implementations, it is the voltage inside the plasma chamber that needs to be flat over a section of the output waveform to achieve a narrow ion energy distribution, requiring the voltage at the output nodes 848, 878 to have a controlled slope over that section of the output waveform. Allowing fine control of these ion energy distribution properties in the plasma may allow fine control of desired outcomes in various material processing applications.

[0123] In the exemplary embodiment of Figures 8B and 8C, generators 840A and 840B may allow for control of such ion energy distribution properties by allowing variable control of the supply voltage of DC voltage source 841 and the switching frequency of switches 842 or 843, respectively. In one illustrative embodiment, switches 842 and 843 of Figures 8B and 8C may allow for selection of a switching frequency of the switched DC voltage, for example, anywhere from 200 kilohertz (kHz) to 1.1 megahertz (MHz). (The switched DC voltage, in various examples, is a DC voltage that is flat or nearly flat over most or a portion of its waveform, and the waveform may also include a voltage switching cycle, which the switching frequency refers to.)

[0124] In Figures 8B and 8C, the nodes of switches 842, 843 shown coupling switches 842, 843 to the peripheral circuitry of generators 840A, 840B may correspond to the terminal nodes of the embodiment of Figures 5A and 5B, i.e., upper node 508 and lower node 546 of stacked switch circuit 501 or upper node 552 and lower node 594 of stacked switch circuit 547. 8B, 8C may also function as a power sink to switches 842, 843 in the exemplary implementation of power sinks 504, 592 of the embodiment of Figures 5A and 5B such that switch 842 or 843 may recover power from voltage clamping internal to switch 842 or 843 and direct the recovered power in a useful form to DC voltage source 841, which may then reuse the recovered power as part of the power it supplies to generators 840A, 840B, respectively. To this end, switch 842 may include a power recovery line (not shown in Figure 8B, otherwise isolated from the remaining circuitry of generator 840A) that directly couples switch 842 to DC voltage source 841 in generator 840A, similar to power recovery output nodes 505, 595 of Figures 5A and 5B, respectively. Switch 843 has a power return line that directly couples switch 843 (particularly the power converter of switch 843) to DC voltage source 841 in generator 840B, as shown in Figure 8C. Generators 840A, 840B are thus configured to clamp the voltage in switches 842, 843, respectively, and to usefully return power from the voltage clamping from switches 842, 843, respectively, to DC voltage source 841.

[0125] In the exemplary embodiment of Figures 8D, 8E, 8F, in contrast to those of Figures 8B and 8C, generators 870A, 870B, 870C may allow variable control of both the supply voltage of DC voltage supply 871 and the rail voltage of DC voltage rail 873, respectively, thereby allowing control of ion energy distribution properties in the plasma load in plasma chamber 879. On the other hand, generators 870A, 870B, 870C may maintain a fixed switching frequency of switches 872, 874, 875, 877, 876, and 896. Generators 870A, 870B, 870C may also advantageously allow control of the average output power per switching cycle by controlling the timing between switching of upper switches 872, 875, 876 and lower switches 874, 877, 896, and thus may be able to control the percentage of time that output 878 is at a high negative voltage.

[0126] In various embodiments of Figure 8D, switches 872 and 874 may be embodied as two of the stacked switch circuits of Figures 5A or 5B. In embodiments of switches 872 and 874 corresponding to embodiments of stacked switch circuits 501 or 547 of Figures 5A, 5B, respectively, the nodes connecting each of switches 872 and 874 to the peripheral circuitry of generator 870A may correspond to upper and lower nodes 508 and 546 or 552 and 594 of Figures 5A or 5B, respectively. In other examples, diodes 880, 881 and switches 872, 874 may be replaced such that diodes 880, 881 connect to DC voltage source 873 and switches 872, 874 may then be implemented as one of the half-bridge stacked switch circuits of Figures 6A, 6B, 7, or 8A. (In these examples, converters 604, 674, 716, 804, 818 may have input terminals that may be exposed to high voltage swings, which may pose challenges to consider with respect to converter implementation.) In a half-bridge stacked switch circuit embodiment of switches 872 and 874, switches 872 and 874, respectively, may correspond to first and second stacked switch circuits of the individual switch circuits of FIG. 6A, 6B, 7, or 8A, i.e., high-side and low-side stacked switch circuits 610 and 616, 662 and 664, 704 and 710, or 808 and 812, respectively. Similarly, in a half-bridge stacked switch circuit embodiment of generator 870A, node 884 of generator 870A may correspond to an individual output node of an individual switch circuit of FIG. 6A, 6B, 7, or 8A that is coupled between the first and second stacked switch circuits, i.e., output nodes 614, 654, 706, 810, respectively.In FIG. 8D, in an embodiment of switches 872 and 874 corresponding to an embodiment of stacked switch circuit 601, 651, 701, or 801 of FIG. 6A, 6B, 7, or 8A, respectively, the outer nodes connecting each of switches 872 and 874 to the peripheral circuitry of generator 870A opposite each of switches 872, 874 from node 884 may correspond to upper and lower nodes 606 and 618, 656 and 668, 702 and 712, or 806 and 814, respectively, of FIG. 6A, 6B, 7, or 8A. The embodiment of generator 870A of FIG. 8D in which switches 872 and 874 are embodied as high-side and low-side stacked switch circuits 808, 812 of stacked switch circuit 801 of FIG. 8A may be directly similar to the embodiment in which switch 872 is embodied as stacked switch circuit 501 of FIG. 5A and switch 874 is embodied as stacked switch circuit 547 of FIG. 5B. In Fig. 8D, in an embodiment of switches 872 and 874 corresponding to the embodiment of stacked switch circuit 601, 651, 701, or 801 of Fig. 6A, 6B, 7, or 8A, respectively, switches 872, 874 each have a power recovery line (not shown in Fig. 8D) coupled to DC voltage source 873 and / or voltage source 871, similar to the power recovery output node between the power converter and DC power source or other power sink in Fig. 6A, 6B, 7, or 8A, respectively, and may employ DC voltage source 873 and / or voltage source 871 as its power sink for useful power recovery (such power recovery line is otherwise isolated from the remaining circuitry of generator 870A). The embodiment of generator 870B in Fig. 8E shows switches 875 and 877 with a power recovery line 887 coupled to voltage source 871 to usefully divert recovered power to voltage source 871. The embodiment of generator 870C in FIG. 8F shows switches 876 and 896 with power recovery line 888 coupled to DC voltage supply 873 to usefully divert recovered power to DC voltage supply 873.

[0127] 8D, the combination of switch 872 and diode 880 creates a switch module that can block voltages of either polarity and conduct current in only one direction, i.e., from anode to cathode through diode 880. Similarly, the combination of switch 874 and diode 881 creates a switch module that can block voltages of either polarity and conduct current in only one direction, i.e., from anode to cathode through diode 881. Similar to using a stacked series combination of individual switch modules to implement switch 872 as series stacked switch 875, diode 880 may be implemented as multiple diodes in series to handle the voltage. Similar to the individual switch modules in switch 875, each diode in the implementation of diode 880 as several diodes in series may potentially be exposed to overvoltage. Substituting a voltage bidirectional two-quadrant switch, created by a series combination of a single-quadrant switch and a diode, for a four-quadrant voltage and current bidirectional switch does not interfere with the operation of the circuit under consideration, and provides a mechanism for protecting all switch modules from overvoltages through voltage clamping of the individual switch modules.

[0128] FIG. 8G illustrates an example implementation of voltage clamping with power recovery in a stacked bidirectional switch circuit, according to an embodiment of the present disclosure. The bidirectional stacked switch 850A of FIG. 8G can potentially be used in the same types of applications as the combination of switch 872 and diode 880 of FIG. 8D, or switch 875 and diode 882 of FIG. 8E, or switch 876 and diode 882 of FIG. 8F, or in any other circuit or system requiring a bidirectional switch. The bidirectional stacked switch circuit 850A with voltage clamping and power recovery includes a forward switch S connected in series with a forward switch S F 851 and reverse switch S R5A and 5B. The forward switch 851 is configured to be able to sustain a positive voltage between the upper node 853 and the midpoint node 854 in the off state, i.e., when all switches in the upper switch 851 are off. The reverse switch 852 is configured to be able to sustain a positive voltage between the lower node 855 and the midpoint node 854 in the off state. The forward switch 851, together with the power converter 856, functions in the same manner as the stacked switch circuit 501 of FIG. 5A, and includes the additional elements G, G A , G B (not shown in FIG. 8G). The upper node 508 of the circuit 501 corresponds to the upper node 853 of the circuit 850A, and the lower node 546 of the circuit 501 corresponds to the midpoint node 854 of the circuit 850A. The power recovery output node 857 of the bidirectional stacked switch 850A may be connected to a power sink (not shown in FIG. 8G), such as a power supply 871 or 873 of a generator 870A, 870B, or 870C, or another suitable power sink. The reverse switch 852, together with the power converter 858, optional capacitor 844 (optional, depending on the topology of the converter 858), and controller 859, connects the midpoint capacitor C, analogous to the power sink 592 of the circuit 547, with the lower node 594 of the switch circuit 547 corresponding to the midpoint node 854 of the circuit 850A of FIG. 8G, and the upper node 552 of the circuit 547 corresponding to the lower node 855 of the circuit 850A. mid 860 may be used to function in a manner similar to the stacked switch circuit 547 of FIG. mid 860 is a capacitor associated with the switch module in the forward switch 851 that is furthest from the power converter 856. mid 860 may act as a temporary storage location for energy resulting from voltage clamping of the voltage in the reverse switch 852. mid The energy stored in 860 is transferred to the midpoint capacitor C midWhen the voltage across 860 exceeds a clamping power set by the input voltage of power converter 856 and the diode voltage drops of the connecting circuitry connecting the individual switch modules to the power converter, it may be transferred to a power sink (not shown in FIG. 8G ) connected to power recovery output node 857. The input voltage of power converter 856 sets the clamping voltage of the switch module of forward switch 851 (up to a few diode voltage drops), while the input voltage of power converter 858, controlled by controller 859, sets the clamping voltage of the switch module of reverse switch 852 (up to a few diode voltage drops). The clamping voltages of the switch modules of the forward switch and the reverse switch may be set to different values.

[0129] 8H illustrates another example implementation of voltage clamping with power recovery in a stacked bidirectional switch circuit, according to an embodiment of the present disclosure. The bidirectional stacked switch 850B of FIG. 8H can potentially be used in the same types of applications as the combination of switch 874 and diode 881 of FIG. 8D, or switch 877 and diode 883 of FIG. 8E, or switch 896 and diode 883 of FIG. 8F, or in any other circuit or system requiring a bidirectional switch. The bidirectional stacked switch circuit 850B with voltage clamping and power recovery includes a forward switch S connected in series with a forward switch S F 861 and reverse switch S R The reverse switch 862, together with the power converter 866, functions in a manner similar to the stacked switch circuit 501 of FIG. 5A, with the additional elements G, G A , G B(not shown in FIG. 8H). The upper node 508 of the circuit 501 corresponds to the lower node 865 of the circuit 850B, and the lower node 546 of the circuit 501 corresponds to the midpoint node 864 of the circuit 850B. The power recovery output node 867 of the bidirectional stacked switch 850B connects to a power sink (not shown in FIG. 8G), such as a power supply 871 or 873 of a generator 870A, 870B, or 870C, or another suitable power sink. The forward switch 861, along with a power converter 868, an optional capacitor 845, and a controller 869, connects to a midpoint capacitor C, similar to the power sink 592 of the circuit 547, with the lower node 594 of the switch circuit 547 corresponding to the midpoint node 864 of the circuit 850B of FIG. 8H, and the upper node 552 of the circuit 547 corresponding to the upper node 863 of the circuit 850B. mid 846 may be used to function in a manner similar to the stacked switch circuit 547 of FIG. 5B. mid 846 is a capacitor associated with the switch module in the reverse switch 862 that is furthest from the power converter 866. mid 846 may act as a temporary storage for energy resulting from voltage clamping of the voltage in the forward switch 861. mid The energy stored in 846 is transferred to the midpoint capacitor C mid When the voltage across 846 exceeds a clamping power set by the input voltage of power converter 866 and the diode voltage drops of the connecting circuitry connecting the individual switch modules to the power converter, it may be transferred to a power sink (not shown in FIG. 8G ) connected to power recovery output node 867. The input voltage of power converter 866 sets the clamping voltage of the switch module of reverse switch 862 (up to a few diode voltage drops), while the input voltage of power converter 868, controlled by controller 869, sets the clamping voltage of the switch module of forward switch 861 (up to a few diode voltage drops). The clamping voltages of the switch modules of the forward switch and the reverse switch may be set to different values.

[0130] In other embodiments, the HOeV, HOeV-like, or other eV-like generators may incorporate any other number and embodiment of stacked switch circuits, any other number and embodiment of power sources, other combinations of controllable choices made possible between the voltages of the power supplies or voltage rails and the switching frequencies of the various switches, and other variations. In various embodiments, including variations of any of the embodiments described or shown above, the switch or switches of the eV-like generator may be embodied as any of the series stacked switch circuits of the present disclosure (e.g., stacked switch circuits 501, 547, 601, 651, 701, 801 as shown in Figures 5A, 5B, 6A, 6B, 7, and 8A, respectively, or bidirectional stacked switch circuits 850A, 850B as shown in Figures 8G and 8H, respectively) or any other variations or extensions thereof. Various embodiments of such eV-like generators may enable the switch to perform voltage clamping with power recovery, which in various embodiments may provide further advantages such as fast reaction time and a high degree of assurance of protection against any potential overheating or damage from an overvoltage event or load voltage shock before the eV-like generator control system is engaged to protect the eV-like generator, as well as useful power recovery from the voltage clamping to an associated power supply, rail, or other useful power sink, reduced power dissipation, and higher efficiency, among other novel advantages.

[0131] Thus, the generator may, in various embodiments, include a power source, a switch circuit connected to the power source via a first generator network, and an output node connected to the power source and the switch circuit via a second generator network. The generator may, in various embodiments, be configured to output power via the output node. The switch circuit may, in various embodiments, include two terminal nodes, including an upper node connected to the high voltage side of the first generator network and a lower node connected to the low voltage side of the first generator network, a plurality of switch modules connected in series between the upper node and the lower node, each switch module including a switch, a rectifier, and a capacitor, a connection circuit coupled to the switch module, and a power converter coupled to one of the connection circuit and the terminal node. The switch circuit may, in various embodiments, be configured to limit a voltage or a component of the voltage in the switch circuit and recover power from the voltage limitation. Recovering power may, in various embodiments, include diverting power from the switch module, via the connection circuit, to the power converter, and the power converter outputting the power to the power source. The generator, in various embodiments, may apply power from a power source across a series of stacked switch modules to an output node, divert power from the switch modules to a power converter, thereby limiting the voltage within the series of stacked switch modules, and output at least a portion of the diverted power from the power converter back to the power source.The stacked series of switch modules may include a forward switch constituting a first portion of the switch module, a reverse switch constituting a second portion of the switch module, a midpoint node coupled between the forward switch and the reverse switch, and a power converter connected to the midpoint node configured to limit a voltage or component of a voltage at either the forward or reverse switch and use a capacitor at the other of the forward or reverse switch as a power sink, where the forward switch can sustain a positive voltage from the upper node to the midpoint node and the reverse switch can sustain a positive voltage from the lower node to the midpoint node. The power source may be the first power source, and the generator may further, in various embodiments, apply power from the second power source directly to the network coupled to the output node. Applying power across a series of stacked switch modules may, in various embodiments, include applying power across a first stacked switch circuit constituting a first portion of the switch module, a second stacked switch circuit constituting a second portion of the switch module, and an output node coupled between the first stacked switch circuit and the second stacked switch circuit. The first stacked switch circuit or the second stacked switch circuit or both the first stacked switch circuit and the second stacked switch circuit may further comprise a forward switch constituting the first portion of the switch module, a reverse switch constituting the second portion of the switch module, a midpoint node coupled between the forward switch and the reverse switch, and a power converter connected to the midpoint node configured to limit a voltage or a component of a voltage in either the forward or reverse switch and use a capacitor in the other of the forward or reverse switch as a power sink, where the forward switch and the reverse switch can sustain voltages of opposite polarity applied across the stacked switch circuit comprising both the forward switch and the reverse switch.

[0132] 9 illustrates a block diagram of an example current clamp 906 with power recovery in a current clamp system 900, according to one embodiment of the disclosure. The current clamp 906 connects a conductive protection branch 908 to a power sink 914 and a feedback branch 926. The current clamp 906 limits the current 916, or a component of the current 916, in the protection branch 908 by diverting power to the power sink 914 in response to any current component occurring in the protection branch 908 that would otherwise drive the current or other particular current component in the protection branch 908 above or outside a specified current limit or other current component limit.

[0133] The current clamp 906 includes a rectifier module 922 and a power converter 924. The rectifier module 922 connects the protection branch 908 to the input of the power converter 924. Current flows from the rectifier module 922 through a control current branch 912 into the power converter 924 and from the power converter 924 back to the rectifier module 922 through a control current feedback branch 918. The power converter 924 includes or is coupled to a controller 925 that maintains a nominally constant current in the control current branch 912 and in the control current feedback branch 918 by directing any excess power to a power sink 914. The power sink 914 may be, for example, a DC rail in a power amplifier or generator, a voltage supply, a current source, or an AC utility source. Optional inductors 910 and 920 in the control current branch 912 and the control current feedback branch 918, respectively, may help maintain nominally constant currents in the control current branch 912 and the control current feedback branch 918. Depending on the design of the power converter 924 and the distance between the rectifier module 922 and the power converter 924, the inductors 910 and 920 may or may not be particularly beneficial or included in different embodiments.

[0134] The protection device 902 may be included or inserted in series with the protection branch 908. The protection device 902 may include, for example, a power device or a MOSFET device, where the drain and source terminals of the power device or MOSFET device may be inserted in series with the protection branch 908, for example. The protection device 902 may have another terminal 904. For example, the protection device 902 may include a power device or switch that receives a reference signal via the terminal 904 for amplification in a generator or power amplifier system that includes the current clamp system 900.

[0135] The design of the rectifier module 922 may determine or contribute to determining the component of the current 916 that is subjected to a current component limit by the current clamp 906. The component of the current that is limited by the current clamp system 900 may be, for example, in various embodiments, the current (i.e., the maximum value of the current), the minimum value of the current, the absolute value of the current, the maximum value of the low frequency component of the current, the absolute value of the high frequency component of the current, the AC component of the current, the RF component of the current, or another current component. The current clamp system may thus be configured to respond to a current component in the protection branch reaching a current component limit by diverting power to a power converter, which in various embodiments may be configured to output at least a portion of the power to a power sink. The current clamp may thus, in various embodiments, apply power to a protection branch that is coupled in series with the rectifier module, which is coupled to the power converter, to limit the current or other current component in the protection branch below the current component limit, and to divert excess power from the limit of the current or other current component from the power converter to the power sink.

[0136] 10A-10K show various exemplary rectifier modules and rectifier module subcircuits (e.g., filters) that may be used in connection with a current clamp with power recovery in various embodiments of the present disclosure, for example, used as or included as part of the rectifier module 922 of FIG. 9, according to various embodiments of the current clamp 906 of FIG. 9. FIG. 10A shows a rectifier capable of limiting a first current i1, 1014 between nodes 1016 and 1004 to a maximum value equal to a second current i2, 1010 between nodes 1008 and 1018. In some cases, the diode 1006 may be replaced by multiple diodes in series to withstand a higher voltage when the diode is in an off state. In FIGS. 10A-10G, the nodes labeled 1-4 correspond to the nodes numbered 1-4 of FIG. The first current i1 may correspond to the protection branch current 916 on the protection branch 908 of FIG. 9, and the second current i2 may correspond to the current in the control current branch 912 of FIG. 9. The same is true with respect to the first and second currents i1 and i2 of FIG. 10B-FIG. 10G. The rectifier of FIG. 10A contains a single diode 1006 as shown, which may also represent multiple series-connected diodes acting like a single diode with a higher effective diode voltage drop in some embodiments. The rectifier of FIG. 10A may optionally include inductors 1002 and 1012, which may correspond to the optional inductors 910 and 920 of FIG. 9. The rectifier of FIG. 10B limits the value of the first current i1 to a minimum value equal to the value of the second current i2. The rectifier of FIG. 10C includes four diodes in a full-bridge configuration and limits the amplitude of the first current i1 to a value equal to the value of the second current i2. The rectifier module of Figure 10D shows optional capacitors 1017, 1019 on the protection and feedback branches, respectively, but is otherwise topologically equivalent to that of Figure 10C, only displayed in a different arrangement. The rectifier module of Figure 10D also includes four diodes in a full-bridge configuration to limit the amplitude of the first current i1 to a value equal to the value of the second current i2.Optional capacitors 1017 and 1019 block the DC component of current i1, and therefore the circuit of FIG. 10D in which optional capacitors 1017 and 1019 are provided is suitable for use in circuits where i1 is not required to have a DC component, such as in AC or RF applications.

[0137] Each of the rectifiers shown in Figures 10A-10C can be combined with a filter 1020 to further select the components of the protection branch current i1 as shown in Figures 10E, 10F, and 10G, respectively, in a rectifier module that may correspond to the rectifier module 922 in the current clamp 906 of Figure 9 according to various embodiments. Several possible topologies for the filter 1020 are shown in Figures 10H-10K. The filter 1022 of Figure 10H contains a single capacitor 1026 and may select the low frequency or DC components of the protection branch current i1 for clamping and allow any high frequency, AC, or RF components of the protection branch current i1 to bypass the current clamp. Using the filter of Figure 10H in the rectifier of Figure 10E, for example, would limit the low frequency or DC components of the protection branch current i1 to i2, but allow the AC or RF components of the protection branch current i1 to proceed above the value of i2. The filter of Figure 10I contains a single inductor 1024 and capacitor 1028 to select the high frequency, AC, or RF components of the protection branch current i1 for clamping and allow the DC or low frequency components of the protection branch current i1 to bypass the current clamp. Using the filter of Figure 10I in the rectifier of Figure 10G, for example, would limit the amplitude of the high frequency, AC, or RF components of the protection branch current i1 to the value of current i2, but would not limit the DC or low frequency components of the protection branch current i1.

[0138] The filter of FIG. 10H does not load the circuit in which the current clamp is used, i.e., the current clamp does not substantially alter the behavior of the circuit when the protection branch current i1 is not within the range in which it is clamped. The filters of FIGS. 10I, 10J, and 10K may load the circuit in which the current clamp is used. For example, the circuit of FIG. 10I creates a high impedance in the protection current branch at the parallel resonance of inductor 1024 and capacitor 1028 when the protection branch current i1 is outside the range in which it is clamped, but does not create a high impedance in the protection current branch at the parallel resonance of inductor 1024 and capacitor 1028 when the protection branch current i1 is within the range in which it is clamped. This is not usually an issue if the circuit in which the current clamp is employed operates in a periodic steady state and the resonance does not substantially affect any of the harmonics of the fundamental frequency. In these and other embodiments, the components of the rectifier module may enable a wide variety of current clamping that may limit any of a variety of desired current components to be clamped according to various embodiments.

[0139] 11A-11F show various power converters (e.g., various embodiments of power converter 924 of FIG. 9) that may be used in conjunction with a current clamp with power recovery in various embodiments of the disclosure. FIG. 11A shows a power converter 1100 in which a current source includes two inductors 1116 and 1120 connected to a full bridge 1104 followed by a buck converter 1105. The power converter 1100 may include a buck converter 1105 in some embodiments in which no isolation between the protection current branch and the power sink is required (i.e., nodes in the protection branch 908 of FIG. 9, such as nodes labeled 1 and 2 of FIG. 9, may share a common ground reference with nodes at the output of the power converter 924, such as nodes labeled 5 and 6 of FIG. 9), and the full bridge 1104 may operate off a voltage higher than the power sink voltage v3 1118. 11A-11F, the current labeled i2 (1102 in FIG. 11A) is the control current branch current, i.e., the current in the control current branch 912 in FIG.

[0140] The buck converter 1105 portion of the power converter 1100 of FIG. 11A includes an input capacitor 1106, a switch 1108, a diode 1126, an inductor 1110, and an output capacitor 1128. The output capacitor 1128 may be part of the power sink rather than part of the buck converter in some embodiments. The buck converter 1105 may be a conventional buck converter, but the power converter 1100 may operate the buck converter 1105 in a manner that does not maintain the output voltage but rather maintains the input voltage constant, and thus the entire power converter 1100 contributes to maintaining the input current, i.e., the control current branch current i2, constant. The full bridge 1104 may be operated in various embodiments to limit the control current branch current i2 and keep it equal to or below a desired clamping current, or to keep another current component equal to or below a desired current component limit. By using a step-down converter 1105 between the current source and the power sink, such as in the power converter 1100 of Figure 11A, the voltage across the input capacitor 1106 can be the body diode voltage drop of the switch 1108 below the power sink voltage v3 1118, i.e., power can be drawn from the power sink to sustain the control current branch current i2 at a desired level, even when no current is flowing in the protection branch 908 as shown in Figure 9. This can help the power converter 1100 maintain the control current branch current i2 at the desired clamping current.

[0141] FIG. 11B illustrates another embodiment in which the power converter 1130 may incorporate a full bridge 1134 and a boost converter 1135 connecting the current source to the power sink. In this embodiment, it may not be possible for the boost converter 1135 alone to maintain the control current branch current i2 at a clamping level. In this case, either both bottom switches of the full bridge 1134 or both top switches of the full bridge 1134 may remain closed while the control current branch current i2 is below the desired clamping level. FIG. 11C illustrates another embodiment of the power converter including a full bridge connecting the current source to the power sink and a buck-boost converter that may be used when no isolation between the protection current branch and the current sink is required. The buck-boost converter may be advantageous because the voltage across the full bridge of the current source may be above or below the voltage of the power sink. FIG. 11D illustrates a power converter in another embodiment including an isolated DC / DC converter that may be used when isolation between the input and output of the converter is required and the power sink is a DC sink such as a DC bus. In Figure 11D, isolation may be achieved with a transformer. Figure 11E shows a power converter in another embodiment that may be advantageous when the power sink is, for example, a single-phase AC utility source 1138. Figure 11F shows a power converter in another embodiment that may be advantageous when the sink is, for example, a three-phase AC utility source 1140.

[0142] FIG. 12A depicts an RF generator 1200 including a current clamp with power recovery to protect a protection branch 1208 and a return branch 1209 (shown in bold) from overcurrent, thereby protecting the RF generator 1200 and a protection power device 1216 from damage due to excessive current in the protection branch 1208. In this embodiment, a DC power supply 1206 provides power to the generator 1200 by maintaining a rail 1205 at a desired voltage relative to a ground reference 1203. The DC power supply typically converts AC power from a utility power supply (not shown) to DC power. In this embodiment, the current clamp includes a rectifier module 1222 and a power converter 1202. The rectifier module 1222 includes four diodes in a full bridge configuration in this embodiment, similar to the rectifier module of FIGS. 10C and 10D. The power converter 1202 includes a switching full-bridge current source and a step-down converter in this embodiment, similar to the power converter embodiment of FIG. 11A. Other embodiments of the rectifier module and power converter may also be used in other embodiments of the generator with current clamping and power recovery. In this embodiment, the power sink is a DC power supply 1206 that feeds a rail 1205 to power the RF generator 1200. In this embodiment, the power sink and current clamp may share a common ground reference, allowing for the use of a non-isolated step-down converter in the converter 1202. The controller 1212 controls the current source and the power converter 1202 in such a way that the current in the control current branch 1224 or another current component is limited to within a desired clamping level for that current component, in different embodiments, such that the control current branch current remains below or at a desired clamping level. This ensures that the current in the protection branch 1208 or a particular current component remains at or below or within a desired clamping level.

[0143] The RF generator 1200 may contain a driver 1220 for driving the power device 1216. The RF generator may be connected to an RF load 1214, such as a plasma load in a plasma chamber, which may also have a matching network attached between the RF generator 1200 and the plasma chamber in some embodiments. The power device 1216 may conduct a reference signal through the RF generator 1200 to drive the RF load 1214, while the current clamp, comprising the rectifier module 1222 and the power converter 1202, may divert any excess power to the rail 1205 and the DC power supply 1206 to limit the current or other current components along the protection branch 1208 to or below a desired current component clamping level. The RF generator 1200 may therefore be configured to respond to a current component in the protection branch reaching a current component limit by diverting power to a power converter, which in various embodiments may be configured to output at least a portion of the power to a power sink. The RF generator 1200 may, in various embodiments, apply power to a protection branch coupled in series with a rectifier module, which in turn may be coupled to a power converter, which may limit the current component on the protection branch below the current component limit and divert excess power from the current component limit from the power converter to a power sink. The current clamp, which comprises the rectifier module 1222 and the power converter 1202, may therefore, in various embodiments, provide effective current clamping with useful power recovery in the RF generator 1200.

[0144] FIG. 12B shows a matching network 1230, which is a solid-state impedance matching network system with current clamping with power recovery, according to another illustrative embodiment. FIG. 12B shows the use of a current clamp with power recovery to limit the current or another current component in the protection branch 1237 and the feedback branch 1240 (shown in bold) in the matching network 1230 in this illustrative embodiment. The matching network 1230 connects the RF generator 1232 to the RF load 1248. A controller 1250 in the solid-state matching network controls a switch 1236 to connect and disconnect a parallel switched capacitor 1234 in a switched capacitor array 1239 to and from the network. The solid-state network also contains fixed components, such as an inductor 1238. In this embodiment, the switched capacitor array 1239 is split into two variable capacitors, one variable capacitor to the left of the inductor 1238 in FIG. 12B and a second variable capacitor to the right of the inductor 1238 in FIG. 12B. The current clamp includes, in this embodiment, a rectifier module 1242 and a power converter 1260. The rectifier module 1242 includes, in this embodiment, four diodes in a full bridge configuration, similar to the rectifier module of FIGS. 10C, 10D, and 12A. The rectifier module 1242 is connected to the power converter 1260. The power converter 1260 is, in this embodiment, configured to deliver the recovered power to a single-phase AC utility source, similar to the power converter of FIG. 11E, and is coupled to an AC utility source 1266 (e.g., an AC power grid connection) and delivers the recovered power to the single-phase AC utility source 1266. Other embodiments of the rectifier module and power converter may also be used in other embodiments of the matching network with current clamping and power recovery.

[0145] The current clamp, which includes the rectifier module 1242 and the power converter 1260, protects components in the protection branch 1237 and the protection feedback branch 1240, such as the two capacitors and the inductor 1241 shown in bold lines, from overcurrent events or current components outside the current component limits imposed by the current clamp, similar to what is described above with respect to the protection device 111 in the embodiment of FIG. 1C. That is, the current clamp, which includes the rectifier module 1242 and the power converter 1260, can protect the inductor 1241 as its protection device in the matching network 1230. In addition to protecting the inductor 1241, limiting the current in the protection branch 1237 can provide protection for other components in the matching network. For example, limiting the current in the protection branch 1237 can protect the switched capacitor array 1239 from experiencing an overvoltage condition.

[0146] Without the current clamping, sudden changes in the characteristics of the RF load 1248, which may be a plasma load, during operation of the circuit may cause overcurrent conditions in the protection branch 1237 and the feedback branch 1240. The feedback branch 1240 is configured with a capacitor and an inductor coupled in series along the feedback branch 1240, as shown in FIG. 12B in this embodiment. The power converter 1260 may include input inductors 1262 and 1264. A controller 1268 of the power converter 1260 operates the power converter 1260 to maintain constant currents in the control current branch 1254 and the control current feedback branch 1252 that are equal to or less than a desired current clamping limit or other current component limit, in various embodiments. The controller 1268 also controls the circuitry of the power converter 1260 to transfer excess power from the current clamping to a single-phase AC utility source 1266, which in this embodiment acts as a power sink. The rectifier module 1242 and power converter 1260 of the matching network 1230, according to the embodiment of FIG. 12B and various further embodiments, therefore provides effective current clamping with useful power recovery for the matching network.

[0147] The matching network 1230 may thus be configured to respond to a current component reaching a current component limit by diverting power to a power converter, thereby limiting the current component in the matching network, which may be configured to output at least a portion of the power to a power sink. The RF generator may apply power to a matching network connecting the RF generator to a load, which in various embodiments may respond to a current component of the current in the matching network reaching a current component limit by diverting power from the matching network, through the rectifier module, to the power converter, thereby limiting the current component in the matching network, and outputting power from the power converter to a power sink.

[0148] In additional embodiments, a generator with voltage component clamping and power recovery as in Figure 4A or current component clamping and power recovery as in Figure 12A, or having both voltage component clamping and current component clamping, may be combined or integrated with a matching network with voltage component clamping as in Figure 4B or current component clamping and power recovery as in Figure 12B, or having both voltage component clamping and current component clamping, in an integrated generator and matching network with voltage component clamping and power recovery as in Figure 4C, similar to the way a generator with voltage component clamping and power recovery as in Figure 4A may be combined or integrated with a matching network with voltage component clamping and power recovery as in Figure 4B, and in some embodiments may be integrated into a single system or device, with various levels of integration. In general, an integrated generator and matching network may include both voltage and current clamping at various locations within the integrated system, in various examples. In various embodiments, an integrated generator plus a matching network with current or voltage component clamping or both and power recovery may have separate dedicated power converters, or a single integrated power converter, which may be configured to connect to separate rectifier modules integrated with both the generator and the matching network and convert the power from the multiple rectifier modules for output in a useful form to a single power sink.

[0149] 13A illustrates an implementation of a generator 1300 incorporating current clamping with power recovery in a parallel switch circuit 1303 according to an embodiment of the present disclosure. In FIG. 13A, the parallel switch circuit 1303 of the generator 1300 includes a number of switches 1302 connected in parallel between a first common node 1315 and a second common node 1317. The generator 1300 generates a source current I s13A. The generator 1300 is powered by a current source 1314 delivering a current 1316. In this embodiment, a load 1306 is placed in parallel with the switch module between the first and second common nodes 1315, 1317. The load 1306 depicted as a resistor may also be any other type of load, such as, for example, a plasma load. Any number of local switch modules 1301 may be included in the switch circuit 1303 of the generator 1300, as indicated by the ellipsis in the center right of the switch circuit as shown in FIG. 13A. In other embodiments, the generator 1300's switch circuit 1303 may include fewer local switch modules than those depicted in FIG. 13A, or any number of two or more local switch modules, including a first switch module 1301A, a last switch module 1301N, and any number of intermediate switch modules 1301 (not individually labeled) placed in parallel between the first switch module 1301A and the last switch module 1301N. Each individual switch 1302 is associated with local network components that together form a local switch module, which may include an individual switch 1302, a local inductor 1308, a local bypass diode 1318, and a local rectifier 1310. A first node of each switch 1302 connects to a first common node. A first node of an individual rectifier local to the individual switch 1302, i.e., in this case a single individual local rectifier diode 1310, connects to a second node of the individual switch, and a second node of the rectifier connects to a first node of an individual local bypass diode 1318. A second node of each individual bypass diode 1318 connects to a second common node 1317. The bypass diodes 1318 and rectifier diodes 1310 are oriented such that current through each switch 1302 flows from anode to cathode through the bypass diodes 1318 and from cathode to anode through at least one diode in the local rectifier 1310 as long as the net current through the rectifier diodes is positive from anode to cathode.

[0150] In the first switch module 1301A (first in the right-to-left order in the depiction of FIG. 13A), the local inductor 1308A is coupled directly between the second node of the local switch 1302A and the second common node 1317, and in each of the other local switch modules, the local inductor 1308 is coupled between the second node of the local switch 1302 and the second terminal of the rectifier diode 1310 (or other rectifier) ​​associated with the previous switch 1302, i.e., the lower right rectifier diode 1310 in the depiction of FIG. 13A. In the last switch module 1301N (last in right-to-left order in the depiction of FIG. 13A ), a second terminal of the rectifier diode 1310N, which is a local rectifier, is connected to a power converter 1324 via a control current branch 1321, which forms one of the inputs of the power converter 1324, while the other input to the power converter 1324 is connected to a second common node 1317. The control current branch 1321 of FIG. 13A may be similar to the control current branch 912 of FIG. 9 in that the power converter 1324 may impose a current limit directly on the control current branch 1321, thereby imposing a current limit on the current through each individual switch 1302.

[0151] Thus, in each individual switch module of the switch modules other than the last switch module 1301N, the rectifier diode 1310 is coupled to a first node between the switch 1302 and the inductor 1308 of the individual switch module and to a second node between the bypass diode 1318 of the switch module under discussion and the inductor 1308 of the subsequent switch module (i.e., of the switch module to the left of the rectifier diode 1310 as shown in FIG. 13A). In the last switch module 1301N, the rectifier diode 1310N is coupled to a first node between the switch 1302N and the inductor 1308N of the last switch module 1301N and to a second node between the bypass diode 1318N of the last switch module and the control current branch 1321 and the power converter 1324, which is also connected to the second common node 1317. In each individual switch module of the switch modules in this embodiment, the rectifier comprises a rectifier diode 1310, which is a first diode, and the individual switch module further comprises a bypass diode 1318, which is a second diode, coupled in series between the local inductor 1308 of the subsequent switch module and the second common node 1317, except for the last switch module, where a bypass diode 1318N is coupled in series between the junction of the rectifier diode 1310N and the control current branch 1321 and the second common node 1317. The inductor 1308 and the rectifier, i.e., the rectifier diode 1310, of the individual switch module locally contribute to limiting the current or other current components of the local switch module below a current component limit.

[0152] During the time the switch is open, current 1312 flows in a loop through inductor 1308, rectifier diode 1310, and optional inductor 1322 (in embodiments where this is included), to and from power converter 1324 through optional inductor 1320 (in embodiments where this is included). During the time the switch is open, power converter 1324 maintains the current in this loop at or below a desired current clamping level by directing any excess power to a power sink 1326. Power converter 1324 is coupled to and may be controlled by controller 1325. The power sink 1326 may be a DC rail, an AC utility supply, or a current source 1314 that supplies power to the circuit (i.e., instead of a separate power sink 1326 as depicted in FIG. 13A , the output node of the power converter 1324 is routed to the current source 1314, which in this exemplary embodiment is configured to supply power to the current source 1314).

[0153] When the switches 1302 are closed, any one of the switches 1302 can draw current through its corresponding local rectifier 1310 and bypass diode 1318 up to the level that was flowing in the inductor 1308 just before the individual switch was closed, but as soon as the current in a particular switch 1302 would otherwise exceed this level, the net current in the corresponding rectifier diode 1310 immediately to the left of the particular switch 1302 as shown in FIG. 13A drops to zero and any further current increase through the particular switch 1302 is forced to go through the individual local inductor 1308 in series with the particular switch 1302. In embodiments where the inductor 1308 is suitably large, this can dramatically inhibit the ability of the current through the particular switch 1302 to not increase significantly above the level of current in the individual local inductor 1308 at the moment the individual switch 1302 is closed, which should have been governed at or below the applicable current component clamping limit by the power converter 1324. The architecture of the switch circuit's switch modules, including the inductor 1308 and rectifier diode 1310 or other comparable rectifier, may thus contribute to locally limiting the current or other current component of each local switch in the switch circuit below a current component clamping limit set by the power converter 1324. The power converter 1324 is configured to keep its input current between zero and a desired clamping current by diverting power to a power sink 1326 whenever the input current of the power converter 1324 would otherwise exceed the desired clamping current, which may help propagate this enforcement of the current component clamping limit throughout the remaining switch circuits 1303 of the generator 1300. The power converter 1324 may thereby impose current clamping with power recovery on all switches 1302 of the switch circuit 1303 of the generator 1300, and the switch circuit 1303 of the generator 1300 may use power recovery to contribute to maintaining its current clamping limits for all switches 1302 of the generator 1300 and the generator 1300.Under most circumstances, only one or some of the switches 1302 will be current limited and any further increase in current through the switch circuit will be through an increase in current through the switches that are not current limited, except for a slow increase in current through the inductor 1308 that corresponds to the switch that is at a current limit. If the total current through the switch circuit 1303 continues to increase, eventually all of the switches 1302 will be at a current limit and the total current through the switch circuit 1303 will be limited to the product of the number of switches and the current limit imposed on each switch module. In this state, the total current through the switch circuit 1303 will increase slowly as the current through the inductor 1308 increases slowly.

[0154] The power converter 1324 is coupled to the second common node 1317 in this embodiment, although the power converter 1324 may also be coupled to the first common current node 1315 in other embodiments. Other embodiments may include a first power converter coupled between the switch module and the first common node and a second power converter coupled between the switch module and the second common node. In these embodiments, both power converters may have outputs connected to a common power sink or to first and second power sinks. The generator 1300 may thus implement effective current clamping and power recovery according to various embodiments.

[0155] The generator 1300 may be configured to output the current clamped power to a load 1306, which may be a load such as a plasma chamber, connected between the first common node and the second common node. The generator 1300 may thus power the load while implementing effective current clamping and power recovery. In various other embodiments, a generator incorporating current clamping with power recovery in a parallel switch circuit may incorporate any of the current clamping elements, techniques, architectures, embodiments, or techniques described above with reference to other current clamping with power recovery and circuits and generators comprising current clamping with power recovery as may be applicable with parallel switch circuits.

[0156] The generator 1300 may thus include a current source, a switch circuit, and a load, all connected between two common nodes, and the generator is configured to output power to the load. The switch circuit may include a plurality of switch modules, each switch module comprising a switch, a rectifier, and an inductor, connected in parallel between the first and second common nodes, and a power converter connected to one of the switch modules and the common nodes and configured to couple to a power sink. The switch circuit may be configured in various embodiments to respond to a current component in the switch circuit reaching a current component limit by diverting power from the power converter to the power sink, thereby limiting the current component in the switch circuit to the current component limit. The generator 1300 may thus apply a current through a switch circuit, including a plurality of switch modules and a power converter, the switch modules connected in parallel between the two common nodes, and the power converter connected to one of the switch modules and the common current node. The generator 1300 may, in various embodiments, respond to a current component in a switch circuit reaching a current component limit by diverting power from the power converter to a power sink, thereby limiting the current component in the switch circuit to the current component limit.

[0157] In further embodiments, elements and features of any of the systems described above may also be combined to provide both voltage component clamping and current component clamping in the same system. Various embodiments may include combined voltage and current clamps, RF generators with both voltage component clamping and current component clamping, eV-like generators with both voltage component clamping and current component clamping, series switch circuits with both voltage component clamping and current component clamping, matching networks with both voltage component clamping and current component clamping, and other systems with both voltage component clamping and current component clamping, according to various embodiments.

[0158] 13B illustrates a generator 1300B incorporating the use of two parallel switch circuits 1330, 1335 with current clamping with power recovery in a half-bridge configuration according to an embodiment of the present disclosure. The switch circuit 1335 may be the same as the switch circuit 1303 described above and is connected between an output node 1352 and a ground reference node 1351. The switch circuit 1335 provides a current limit I CL1354. The switch circuit 1330 is similar to the switch circuit 1335, except that it is turned upside down relative to the switch circuit 1335 and the polarity of the diodes in the switch circuit 1330 is reversed compared to that of the switch circuit 1335. These modifications of the switch circuit 1330 relative to the switch circuit 1335 may be beneficial in various applications because with these modifications, the input of the power converter of the switch 1330 is referenced to the node 1350, which is the rail, which is stable relative to the ground reference node 1351. That is, the rail node 1350 in this application remains at a fixed voltage relative to the ground reference 1351. Some embodiments may replicate the switch 1335 and use the circuitry of the switch 1335 with respect to the switch 1330, but in that case the power converter of the switch 1330 is referenced to the output node 1352, which is not stable relative to the ground reference 1351, which may pose challenges to consider in the implementation of the power converter of the switch 1330. In the circuit chosen for switches 1335 and 1330, beneficially, the power sink for the power converters of both switches may be the DC power source 1340. As depicted in FIG. 13B , the power sink is internal to the DC source 1340, which may be, for example, a bus voltage, such as a rectified AC utility input to the DC source 1340. In other implementations, the power sink may be the output of the DC source 1340, i.e., the outputs of the power converters of switches 1330 and 1335 may also be connected to the rail 1350 and ground reference 1351. The switch circuit 1330 provides a current limit I CU 1353. This limit is limited by the current limit I CL 1354. A load 1345, which may be a plasma load, may be connected between the output node 1352 and a ground reference node 1351. A load may also be connected between the output node and the rail voltage node 1350, if so desired. Additional circuitry (not shown), such as a DC block, filter, or measurement system, may be connected between the output node 1352 and the load.

[0159] FIG. 14 depicts a flowchart for an exemplary method 1400 in another embodiment of the disclosure. The method 1400 includes connecting the protection node and the reference node to a rectifier (1410). The method 1400 further includes connecting the rectifier to an input of a power converter (1420). The method 1400 further includes connecting an output of the power converter to a power sink (1430). The method 1400 further includes operating the power converter to maintain the converter input voltage between zero volts (0V) and a desired clamping voltage by diverting power to a power sink when the converter input voltage exceeds the desired clamping voltage such that a component of a voltage difference between the protection node and the reference node is limited to the sum of the converter input voltage and the rectifier voltage drop (1440).

[0160] FIG. 15 depicts a flowchart for an exemplary method 1500 in another embodiment of the present disclosure. The method 1500 includes connecting several switches in series, each having a first and second node between an upper node and a lower node, such that a first node of a first switch is connected to an upper node, a first node of each successive switch is connected to a second node of a preceding switch, and a second node of a last switch is connected to a lower node (1510). The method 1500 further includes connecting a rectifier associated with each switch to the first and second nodes of the switch with which the rectifier is associated (1520). The method 1500 further includes connecting a capacitor associated with each rectifier to each rectifier in such a way that a voltage difference between the first and second nodes of the associated switch is limited to the sum of a capacitor voltage and a rectifier voltage drop (1530). Method 1500 further includes maintaining the voltage of each capacitor associated with each switch between zero and a desired clamping voltage (plus a small voltage caused by a diode voltage drop in the circuit) by an arrangement of diodes and optional circuit elements such that when all switches are closed, current may flow through any capacitor with a voltage exceeding a desired clamping voltage (plus a small voltage caused by a diode voltage drop in the circuit) and through the converter connected to one of the upper or lower nodes, thereby partially discharging the capacitor and reducing the capacitor voltage to a value between zero and the desired clamping voltage (1540). Method 1500 further includes operating the converter in a manner such that the voltage of the capacitor is maintained between zero and a desired clamping voltage (plus a small voltage caused by a diode voltage drop in the circuit, which may be different for each capacitor) by diverting power to a power sink when the voltage of any capacitor exceeds the desired value (1550).

[0161] FIG. 16 depicts a flowchart for an example method 1600 in another embodiment of the disclosure. The method 1600 includes connecting a rectifier in series with the protection branch (1610). The method 1600 further includes connecting the rectifier to an input of the power converter (1620). The method 1600 further includes connecting an output of the power converter to a power sink (1630). The method 1600 further includes operating the power converter to maintain the converter input current between zero amperes (0A) and a desired clamping current by diverting power to a power sink when the converter input current exceeds a desired clamping current such that a component of the current in the protection branch is limited to the converter input current (1640).

[0162] FIG. 17 depicts a flow chart for an exemplary method 1700 in another embodiment of the present disclosure. The method 1700 includes connecting several switches in parallel, each having a first and a second node, such that the first nodes of all the switches connect to a first common node (1710). The method 1700 further includes connecting a first terminal of a rectifier associated with each switch to a second node of the switch with which the rectifier is associated in such a manner that when the switch is closed, the switch current flows from the cathode to the anode in at least one diode of the rectifier (1720). The method 1700 further includes connecting a diode associated with each switch between the second common node and the second terminal of the rectifier in such a manner that when the switch is closed, the switch current flows from the anode to the cathode through the diode (1730). The method 1700 further includes connecting the inductors associated with each switch such that the inductor associated with the first switch connects directly between the second terminal of the switch and the second common node, and the inductor associated with the successive switch connects between the second terminal of the switch and the second terminal of the rectifier associated with the previous switch (1740). The method 1700 further includes maintaining a current in each inductor associated with each switch between zero and a desired clamping current when all switches are open with the power converter connected between the second terminal of the rectifier associated with the last switch and the second common node and current flowing in a loop consisting of all inductors, all rectifiers, and the power converter (1750). The method 1700 further includes operating the power converter in a manner such that the power converter input current remains between zero and the desired clamping current by diverting power to a power sink when the power converter input current exceeds the desired clamping current (1760).

[0163] 18 depicts a block diagram of an exemplary computing system 1800 that may embody, control, or execute any of the various embodiments of the voltage clamps, current clamps, generators, matching networks, and other systems, methods, and apparatus disclosed herein in various embodiments of the present disclosure. For example, computing system 1800 may serve as an embodiment of controller 412, controller 450, controller 468, controller 1212, controller 1250, or controller 1268 as depicted in and described above with reference to FIGS. 4A, 4B, 12A, and 12B, respectively. As a further example, the computing system 1800 may implement, execute, or embody any of the methods 1400, 1500, 1600, 1700, 2000, 2100, 2200, 2300, 2400, 2500, 2600, or 2700 as depicted in and described above with reference to FIGS. 14-17 and 20-27, respectively. The computing system 1800 may be a server, such as a web server or an application server. The computing system 1800 may also be any server for providing the power harvesting clamp application in various embodiments, including a virtual server, which may be launched from or incorporate any number of computing devices. The computing devices may operate as all or part of a real or virtual server, and may be or incorporate a workstation, server, mainframe computer, notebook or laptop computer, desktop computer, tablet, smartphone, or any type of other programmable data processing device. Other implementations of computing system 1800 may include computers having other or greater capabilities or formats than those described herein.

[0164] In the illustrative embodiment of FIG. 18 , computing system 1800 includes a communication bus 1882 that provides communication between one or more processor units 1884, one or more memory devices 1886, one or more persistent data storage devices 1888, one or more communication units 1890, and one or more input / output (I / O) units 1892. Communication bus 1882 may include a special-purpose system bus, a general-purpose system bus, multiple buses arranged in a hierarchical configuration, any other type of bus, a bus network, a switch fabric, or other interconnection technology. Communication bus 1882 supports the transfer of data, commands, and other information between various subsystems of computing system 1800.

[0165] The processor unit 1884 may be a programmable central processing unit (CPU) configured to execute programmed instructions stored in one or more memory devices 1886. In another illustrative example, the processor unit 1884 may be implemented using one or more heterogeneous processor systems in which a main processor resides on a single chip with secondary processors. In another illustrative example, the processor unit 1884 may be a symmetric multiprocessor system containing multiple processors of the same type. The processor unit 1884 may be a reduced instruction set computing (RISC) microprocessor, an x86 compatible processor, or any other suitable processor. In various embodiments, the processor unit 1884 may include, for example, a multi-core processor. The processor unit 1884 may include, for example, multiple processing chips on a single die, and / or multiple dies on a single package or substrate. The processor unit 1884 may also include, for example, one or more levels of integrated cache memory. In various embodiments, processor unit 1884 may comprise one or more CPUs distributed across one or more locations.

[0166] The data storage 1896 includes one or more memory devices 1886 and one or more persistent data storage devices 1888 in communication with the processor unit 1884 through a communication bus 1882. The memory devices 1886 may include one or more random access semiconductor memory (RAM) devices for storing application data, i.e., computer program data, for processing. Although the memory devices 1886 are depicted as a single monolithic block, in various embodiments the memory devices 1886 may be arranged within a hierarchy of caches and other memory devices, within a single physical location, or distributed across multiple physical systems in various configurations. Although memory device 1886 is depicted as physically separate from processor unit 1884 and other elements of computing system 1800, memory device 1886 may equally refer to any intermediate or cache memory anywhere throughout computing system 1800, including cache memory proximate to or integrated with processor unit 1884 or individual cores of processor unit 1884.

[0167] The persistent data storage device 1888 may include one or more hard disk drives, solid state drives, flash drives, rewritable optical disk drives, magnetic tape drives, or any combination of these or other data storage media. The persistent data storage device 1888 may store computer-executable instructions for an operating system or application files comprising computer-readable program code, program code, data structures, or data files, and any other type of data. These computer-executable instructions may be loaded from the persistent data storage device 1888 into the memory device 1886 and read and executed by the processor unit 1884 or other processor. The data storage device 1896 may also include any other hardware elements capable of storing information, such as, for example, but not limited to, data, program code in a functional form, and / or other suitable information, either temporarily and / or permanently.

[0168] Persistent data storage device 1888 and memory device 1886 are examples of physical, tangible, non-transient computer-readable data storage devices. Data storage device 1896 may include any of a variety of forms of volatile memory, which may require periodic electrical refresh to maintain data in the memory, but those skilled in the art will recognize that this also constitutes an example of a physical, tangible, non-transient computer-readable data storage device. Executable instructions may be stored on non-transient media, including only for a short duration or only in a volatile memory format, when program code is loaded, stored, relayed, buffered, or cached on a non-transient physical medium or device.

[0169] The processor unit 1884 may also be suitably programmed to read, load, and execute computer-executable instructions or computer-readable program code for the power recovery clamp system 1822, as described in more detail above. The program code may be stored on the memory device 1886, the persistent data storage device 1888, or elsewhere within the computing system 1800. The program code may also take the form of executable program code 1804 stored on a computer-readable medium 1802 configured in a computer program product 1810, as described further below, and may be transferred or communicated from the computer program product 1810 to the computing system 1800 through any of a variety of local or remote means to be enabled for execution by the processor unit 1884.

[0170] The operating system may provide functions such as device interface management, memory management, and multiple task management. The operating system may be a Unix-based operating system, a non-Unix-based operating system, a network operating system, a real-time operating system (RTOS), or any other suitable operating system. Processor unit 1884 may be suitably programmed to read, load, and execute instructions of the operating system.

[0171] The communications unit 1890, in this embodiment, provides for communication with other computing or communication systems or devices. The communications unit 1890 may provide communication through the use of physical and / or wireless communication links. The communications unit 1890 may include a network interface card to interface with a local area network (LAN), an Ethernet adapter, a token ring adapter, a modem for connecting to a transmission system such as a telephone line, or any other type of communications interface. The communications unit 1890 may be used to operatively connect many types of peripheral computing devices, such as printers, bus adapters, and other computers, to the computing system 1800. The communications unit 1890 may be implemented, for example, as an expansion card or embedded within a motherboard.

[0172] The input / output unit 1892 may support suitable devices for input and output of data using other devices that may be connected to the computing system 1800, such as a keyboard, a mouse or other pointer, a touch screen interface, an interface for a printer or any other peripheral device, a removable magnetic or optical disk drive (including CD-ROM, DVD-ROM, or Blu-Ray), a universal serial bus (USB) receptacle, or any other type of input and / or output device. The input / output unit 1892 may also, in various embodiments, include any type of interface for video output in any type of video output protocol and any type of monitor or other video display technology. Some of these embodiments may overlap with each other or with the illustrative components of the communications unit 1890 or the data storage device 1896. The input / output unit 1892 may also include appropriate device drivers for any type of external device, or such device drivers may reside elsewhere on the computing system 1800, as appropriate.

[0173] The computing system 1800 also includes, in this illustrative embodiment, a display adapter 1894, which provides one or more connections for one or more display devices, such as a display device 1898, which may include any of various types of display devices. Some of these embodiments may overlap with the illustrative components of the communication unit 1890 or the input / output unit 1892. The input / output unit 1892 may also include appropriate device drivers for any type of external device, or such device drivers may reside elsewhere on the computing system 1800, as appropriate. The display adapter 1894, in various embodiments, may include one or more video cards, one or more graphics processing units (GPUs), one or more video-enabled connection ports, or any other type of data connector capable of communicating video data. The display device 1898, in various embodiments, may be any type of video display device, such as a monitor, television, or projector.

[0174] The input / output unit 1892 may include a drive, socket, or receptacle for receiving a computer program product 1810, which comprises a tangible, non-transitory computer readable medium 1802 having executable program code 1804 stored thereon. For example, the computer program product 1810 may be, as illustrative examples, a CD-ROM, a DVD-ROM, a Blu-Ray® disk, a magnetic disk, a USB stick, a flash drive, or an external hard disk drive, or any other suitable data storage technology.

[0175] The computer readable medium 1802 may include any type of optical, magnetic, or other physical medium that physically encodes the executable program code 1804 as a binary sequence of different physical states within each unit of memory, which, when read by the computing system 1800, induces physical signals, read by the processor unit 1884, that correspond to physical states of the underlying data storage elements of the computer readable medium 1802 and induces corresponding changes in physical states in the processor unit 1884. The physical program code signals may be modeled or conceptualized as computer-readable instructions at any of various levels of abstraction, such as a high-level programming language, assembly language, or machine language, but ultimately comprise a series of electrical and / or magnetic interactions that physically induce a change in the physical state of the processor unit 1884, thereby physically reconfiguring the processor unit 1884 to generate or configure the processor unit 1884 to generate physical output corresponding to the computer-executable instructions in a manner that causes the computing system 1800 to physically assume new capabilities that it did not have until its physical state was changed, by loading executable instructions configured in the executable program code 1804.

[0176] In some demonstrative examples, executable program code 1804 may be downloaded from another device or computer system via a network to data storage device 1896 for use within computing system 1800. Executable program code 1804 comprising computer-executable instructions may be communicated or transferred from computer readable medium 1802 to computing system 1800 through a wired or wireless communication link to communication unit 1890 and / or through a connection to input / output unit 1892. Computer readable medium 1802 comprising executable program code 1804 may be located separate or remote from computing system 1800, may be located anywhere, including at any remote geographic location anywhere around the world or in orbit, and may relay executable program code 1804 to computing system 1800 via one or more communications links of any type, such as the Internet and / or other packet data networks. The executable program code 1804 may be transmitted, for example, via a wireless Internet connection or via a shorter range direct wireless connection such as a wireless LAN, Bluetooth, Wi-Fi, or infrared connection. Any other wireless or remote communication protocol may also be used in other implementations.

[0177] The communications links and / or connections may include wired and / or wireless connections in various illustrative examples, and the executable program code 1804 may be transmitted from the source computer readable medium 1802 via a communications link or a non-tangible medium, such as a wireless transmission, containing the executable program code 1804. En route from its original source medium to the computing system 1800, the executable program code 1804 may be stored, more or less temporarily or permanently, on any number of intermediate tangible physical computer readable devices and media, such as any number of physical buffers, caches, main memories, or data storage components of servers, gateways, network nodes, mobility management entities, or other network assets.

[0178] Various exemplary embodiments of the present disclosure may be in the form of a system, method, and / or computer program product. The computer program product may include a computer-readable storage medium (or media) having computer-readable program instructions thereon for causing a processor to perform aspects of the embodiments of the present disclosure.

[0179] A computer readable storage medium may be a tangible device that may retain and store instructions for use by an instruction execution device. A computer readable storage medium may be, for example, but not limited to, an electronic storage device, a magnetic storage device, an optical storage device, an electromagnetic storage device, a semiconductor storage device, or any suitable combination of the foregoing. A non-exhaustive list of more specific examples of computer readable storage media includes the following: portable computer diskettes, hard disks, random access memories (RAMs), read only memories (ROMs), erasable programmable read only memories (EPROMs or flash memories), static random access memories (SRAMs), portable compact disk read only memories (CD-ROMs), digital versatile disks (DVDs), memory sticks, floppy disks, punch cards or mechanically encoded devices such as ridge structures in grooves having instructions recorded thereon, and any suitable combination of the foregoing. A computer-readable storage medium as used herein is not to be construed as being a transitory signal per se, such as radio waves or other freely propagating electromagnetic waves, electromagnetic waves propagating through a waveguide or other transmission medium (e.g., light pulses passing through a fiber optic cable), or electrical signals transmitted through wires.

[0180] The computer-readable program instructions described herein can be downloaded from a computer-readable storage medium to an individual computing / processing device or to an external computer or storage device over a network, such as the Internet, a local area network, a wide area network, and / or a wireless network. The network may comprise copper transmission cables, optical transmission fiber, wireless transmission, routers, firewalls, switches, gateway computers, and / or edge servers. A network adapter card or network interface in each computing / processing device receives the computer-readable program instructions from the network and automatically transfers the computer-readable program instructions for storage in a computer-readable storage medium in the individual computing / processing device.

[0181] The computer readable program instructions for performing the operations of the present invention may be either source code or object code written in any combination of one or more programming languages, including assembler instructions, instruction set architecture (ISA) instructions, machine instructions, machine dependent instructions, microcode, firmware instructions, state setting data, or object code written in any combination of one or more programming languages, including object oriented programming languages ​​such as C++ or Java, imperative programming languages ​​such as C, specialized languages ​​such as Hardware Description Languages ​​(HDLs), Lisp programming languages ​​such as Common Lisp, Racket, or Clojure, other functional programming languages ​​such as Haskell or Erlang, or multi-paradigm languages ​​such as Python or Rust. The computer readable program instructions may be executed entirely on the user's computer, partially on the user's computer, partially on the user's computer as a stand-alone software package and partially on a remote computer, or entirely on a remote computer or server. In the latter scenario, the remote computer may be connected to the user's computer through any type of network, including a local area network (LAN) or wide area network (WAN), or the connection may be made to an external computer (e.g., through the Internet using an Internet Service Provider (ISP)). In some embodiments, electronic circuitry, including, for example, programmable logic circuitry, field programmable gate arrays (FPGAs), or programmable logic arrays (PLAs), may execute computer readable program instructions and personalize the electronic circuitry by utilizing state information of the computer readable program instructions to implement aspects of embodiments of the present disclosure.

[0182] Aspects of the present invention are described herein with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the invention. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer readable program instructions.

[0183] These computer-readable program instructions may be provided to a processor of a general purpose computer, special purpose computer, or other programmable data processing apparatus to produce a machine, such that the instructions, executed by the processor of the computer or other programmable data processing apparatus, generate means for implementing the function / acts defined in the block or blocks of the flowcharts and / or block diagrams. These computer-readable program instructions may also be stored in a computer-readable storage medium that may instruct a computer, programmable data processing apparatus, and / or other device to function in a particular manner, such that the computer-readable storage medium having instructions stored therein comprises an article of manufacture that includes instructions that implement aspects of the function / acts defined in the block or blocks of the flowcharts and / or block diagrams.

[0184] The computer-readable program instructions may also be loaded onto a computer, other programmable data processing apparatus, or other device such that the instructions, which execute on the computer, other programmable apparatus, or other device, implement the functions, acts, or steps defined in a block or blocks of the flowcharts and / or block diagrams, causing a sequence of operational steps to be performed on the computer, other programmable apparatus, or other device to produce a computer-implemented process.

[0185] The flowcharts and block diagrams in the figures illustrate the architecture, functionality, and operation of possible implementations of systems, methods, and computer program products according to various embodiments of the present disclosure. In this regard, each block in the flowchart or block diagram may represent a module, partition, or part of an instruction, which comprises one or more executable instructions for implementing the specified logical function. In some alternative implementations, the functions described in the blocks may occur in a different order than described in the figures. For example, two blocks shown in succession may in fact be executed substantially in parallel, or the blocks may sometimes be executed in reverse order, depending on the functionality involved. Each block of the block diagrams and / or flowchart illustrations, and combinations of blocks in the block diagrams and / or flowchart illustrations, may also be implemented by a special-purpose hardware-based system that performs the specified functions or acts, or a combination of special-purpose hardware and computer instructions.

[0186] Those skilled in the art will further appreciate that the various illustrative logic blocks, modules, circuits, and algorithm steps described in connection with the embodiments disclosed herein may be implemented as electronic hardware, computer software, or a combination of both. To clearly illustrate this interchangeability of hardware and software, the various illustrative components, blocks, modules, circuits, and steps have been described above generally in terms of their functionality. Whether such functionality is implemented as hardware or software depends on the particular application and design constraints imposed on the overall system. Those skilled in the art may implement the described functionality in various ways for each particular application, but such implementation decisions should not be interpreted as causing a departure from the scope of the present invention.

[0187] The various illustrative logic blocks, modules, and circuits described in connection with the embodiments disclosed herein may be implemented or performed using a general purpose processor, a digital signal processor (DSP), an application specific integrated circuit (ASIC), a field programmable gate array (FPGA), or other programmable logic device, discrete gate or transistor logic, discrete hardware components, or any combination thereof, designed to perform the functions described herein. A general purpose processor may be a microprocessor, but in the alternative, the processor may be any conventional processor, controller, microcontroller, or state machine. A processor may also be implemented as a combination of computing devices, such as a combination of a DSP and a microprocessor, multiple microprocessors, one or more microprocessors in conjunction with a DSP core, or any other such configuration.

[0188] FIG. 19 depicts a conceptual block diagram of exemplary physical components of a system 1450 that may implement, execute, or embody one or more aspects of various embodiments of the voltage clamp, current clamp, generator, matching network, and other systems, methods, and apparatus disclosed herein. As shown, in this embodiment, a display 1412 and a non-volatile memory 1429 are coupled to a bus 1422, which is also coupled to a random access memory ("RAM") 1424, a processing portion 1426 (including N processing components), a field programmable gate array (FPGA) 1427, and a transceiver component 1428, including N transceivers. Although the components depicted in FIG. 26 represent physical components, FIG. 26 is not intended to be a detailed hardware diagram, and thus many of the components depicted in FIG. 26 may be realized by a common structure or distributed among additional physical components. It is also envisioned that other existing and yet to be developed physical components and architectures may be utilized to implement the functional components described with reference to FIG. 26.

[0189] The display 1412 generally operates to provide a user interface for a user, and in some implementations, the display 1412 is realized by a touch screen display. For example, the display 1412 can be used to control and interact with the components described herein. In general, the non-volatile memory 1429 is a non-transient memory that functions to store (e.g., persistently store) data and machine-readable (e.g., processor-executable) code (including executable code associated with effecting the methods described herein). In some embodiments, for example, the non-volatile memory 1429 includes boot loader code, operating system code, file system code, and non-transient processor-executable code to facilitate execution of the methods described herein.

[0190] In many implementations, the non-volatile memory 1429 is realized by a flash memory (e.g., NAND or ONENAND memory), although it is envisioned that other memory types may be utilized as well. While it may be possible to execute code from the non-volatile memory 1429, executable code in the non-volatile memory is typically loaded into RAM 1424 and executed by one or more of the N processing components in the processing portion 1426.

[0191] In operation, the N processing components in communication with the RAM 1424 may generally operate to execute instructions stored in the non-volatile memory 1429 to implement the functionality of the power recovery circuitry described herein. For example, non-transient processor-executable instructions for effecting the methods described herein may be persistently stored in the non-volatile memory 1429 and executed by the N processing components in communication with the RAM 1424. As one skilled in the art would appreciate, the processing portion 1426 may include a video processor, a digital signal processor (DSP), a graphics processing unit (GPU), and other processing components.

[0192] Additionally or alternatively, a field programmable gate array (FPGA) 1427 may be configured to effect one or more aspects of the methodologies described herein. For example, non-transient FPGA configuration instructions may be persistently stored in non-volatile memory 1429 and accessed by FPGA 1427 (e.g., during power-up) to configure FPGA 1427.

[0193] The input components may operate to receive signals indicative of voltage and / or current (e.g., from voltage amplitude measurement circuitry and / or current amplitude measurement circuitry associated with a controller such as controllers 162, 412, 450, 468, 1212, 1250, 1268 as described above). The output components generally operate to provide one or more analog or digital signals (e.g., to prompt drive signals to switches in power converter 118 or other switches or circuitry of a voltage clamp or current clamp system as described herein) to effect operational aspects of a voltage clamp or current clamp with power recovery or other systems as described herein.

[0194] The depicted transceiver component 1428 includes N transceiver chains, which may be used to communicate with external devices (e.g., an external controller) over a wireless or wired network. Each of the N transceiver chains may represent a transceiver associated with a particular communication scheme (e.g., WiFi, Ethernet, Profibus, etc.).

[0195] FIG. 20 depicts a flow chart for an example method 2000 in another embodiment of the disclosure. The method 2000 includes applying a voltage across a plurality of switch modules connected in series between two terminal nodes, each switch module including a switch, a rectifier, and a capacitor (2010). The method 2000 further includes diverting power from the switch modules through a connection circuit coupled to the switch modules to a power converter coupled to the connection circuit and to a power sink, thereby limiting a component of the voltage across one or more of the switches and / or switch modules, and recovering power from the voltage limit to the power sink (2020). The power converter may also be coupled to one of the terminal nodes in some examples.

[0196] FIG. 21 depicts a flow chart for an example method 2100 in another embodiment of the disclosure. The method 2100 includes providing power from a power source, through an intermediate network, to a power output terminal (2110). The method 2100 further includes diverting power to a power converter if not diverting the power would result in a component of the voltage in the intermediate network exceeding a voltage component limit (2120). The method 2100 further includes outputting at least a portion of the power from the power converter to a power sink (2130) so that the power may be reused. The method 2100 may include other steps or variations in various other embodiments.

[0197] 22 depicts a flow chart for an example method 2200 in another embodiment of the disclosure. The method 2200 includes applying power to a matching network connected to a load (2210). The method 2200 further includes responding to a component of the voltage in the matching network reaching a voltage component limit by diverting power from the matching network through a rectifier module to a power converter connected to a power sink (2220), thereby limiting the component of the voltage in the matching network. The method 2200 further includes outputting power from the power converter to a power sink (2230). The method 2200 may include other steps or variations in various other embodiments.

[0198] 23 depicts a flow chart for an example method 2300 in another embodiment of the disclosure. The method 2300 includes controlling or modulating power from a power source to a load using a switch circuit comprising a series of stacked switch modules (2310). The method 2300 further includes diverting power from the switch module to a power converter, thereby limiting a component of voltage across the switch module (2320). The method 2300 further includes outputting at least a portion of the diverted power from the power converter back to the power source (2330). The method 2300 may include other steps or variations in various other embodiments.

[0199] 24 depicts a flow chart for an example method 2400 in another embodiment of the disclosure. The method 2400 includes conducting a current through a protection branch coupled in series with a rectifier module, the rectifier module coupled to a power converter coupled to a power sink (2410). The method 2400 further includes limiting a component of the current through the protection branch to less than or equal to a current component limit (2420). The method 2400 further includes diverting excess power from the limiting of the current component from the power converter to the power sink (2430). The method 2400 may include other steps or variations in various other embodiments.

[0200] 25 depicts a flow chart for an example method 2500 in another embodiment of the disclosure. The method 2500 includes conducting a current through a switch circuit comprising a plurality of switch modules and a power converter, the switch modules being connected in parallel between two common nodes, and the power converter being connected to the switch modules and a power sink (2510). The method 2500 further includes responding to a current component in the switch circuit reaching a current component limit by diverting power to the power sink with the power converter, thereby limiting the current component in the switch circuit to the current component limit (2520). The method 2500 may include other steps or variations in various other embodiments.

[0201] 26 depicts a flow chart for an example method 2600 in another embodiment of the disclosure. The method 2600 includes applying power to a matching network connected to a load (2610). The method 2600 further includes responding to a current component of the current in the matching network reaching a current component limit by diverting power from the matching network, through a rectifier module, to a power converter, thereby limiting the current component in the matching network (2620). The method 2600 further includes outputting the power from the power converter to a power sink (2630). The method 2600 may include other steps or variations in various other embodiments.

[0202] 27 depicts a flow chart for an example method 2700 in another embodiment of the disclosure. The method 2700 includes controlling or modulating power delivered to a load with a switch circuit comprising a plurality of switch modules and a power converter, the switch modules being connected in parallel between two common nodes, and the power converter being connected to the switch modules and a power sink (2710). The method 2700 further includes responding to a current component in the switch circuit reaching a current component limit by diverting power from the power converter to the power sink, thereby limiting the current component in the switch circuit to the current component limit (2720). The method 2700 may include other steps or variations in various other embodiments.

[0203] The methods 1400, 1500, 1600, 1700, 2000, 2100, 2200, 2300, 2400, 2500, 2600, 2700 may include other steps or variations in various alternative embodiments. Some or all of any of methods 1400, 1500, 1600, 1700, 2000, 2100, 2200, 2300, 2400, 2500, 2600, or 2700 may be performed by or embodied in hardware and / or performed by a controller, CPU, FPGA, SoC, measurement and control multiprocessor system on a chip (MPSoC), which may include both a CPU and FPGA, and other elements together within an integrated SoC or other processing or computing device that processes executable instructions in controlling other associated hardware, devices, systems, or products in performing, implementing, or embodying various subject matter of the methods.

[0204] Voltage clamping with power recovery and current clamping with power recovery are thus shown and described herein in various fundamental aspects, and in various selected illustrative applications, architectures, techniques, and methods for voltage clamping with power recovery. Those skilled in the art will be sufficiently informed by this disclosure for an informed simplification to the understanding and practice of a broad set of additional applications, architectures, techniques, and methods for voltage clamping with power recovery and current clamping with power recovery that are encompassed by this disclosure and by the claims set forth below.

[0205] As used herein, the recitation of "at least one of A, B, and C" is intended to mean "either A, B, C, or any combination of A, B, and C." The foregoing description of the disclosed embodiments is provided to enable any person skilled in the art to make or use the present disclosure. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be applied to other embodiments without departing from the spirit or scope of the present disclosure. Thus, the present disclosure is not intended to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

[0206] It is believed that the present disclosure and many of its attendant advantages will be understood from the foregoing description, and it will be apparent that various changes can be made in the form, construction and arrangement of the components without departing from the disclosed subject matter or sacrificing all of its significant advantages. The described forms are merely illustrative, and it is intended that the following claims encompass and include the broadest range of embodiments encompassing any such modifications.

[0207] Although the present disclosure has been described with reference to various embodiments, it should be understood that these embodiments are illustrative and that the scope of the present disclosure is not limited thereto. Many variations, modifications, and additions are possible within the scope of the embodiments of the present disclosure. More generally, the embodiments according to the present disclosure are described in the context of specific implementations. Functionality may be separated or combined in blocks differently or described using different terminology in various embodiments of the present disclosure. These and other variations, modifications, additions, and improvements may fall within the scope of the present disclosure as defined in the following claims.

Claims

1. A switch circuit, two terminal nodes including an upper node and a lower node; a plurality of switch modules connected in series between the upper node and the lower node, each of the switch modules comprising a switch, a rectifier, and a capacitor; a connection circuit coupled to the switch module; a power converter coupled to the connection circuit and to a power sink; Equipped with the switch circuit is configured to limit a voltage or a component of a voltage in the switch circuit and recover power from the limiting of the voltage; recovering the power includes diverting power from the switch module through the connecting circuit to the power converter, and the power converter outputting the power to the power sink. Switch circuit.

2. The switch circuit of claim 1 , wherein the switch circuit is further configured to limit a voltage or a component of a voltage across one or more individual switches of the switch module.

3. 3. The switch circuit of claim 2, further configured to limit the voltage across the one or more individual switches of one or more individual switch modules to a sum of a nominal capacitor voltage of a capacitor of the individual switch module and a rectifier voltage drop of a rectifier of the individual switch module.

4. The switch circuit of claim 1 , wherein the connection circuit comprises a series stack of diodes, the diodes being coupled to the switch module.

5. The connection circuit further comprises a plurality of switches coupled to the diodes; The power converter comprises a distributed power converter, the distributed power converter comprising the switch configured in the connection circuit.

5. The switch circuit according to claim 4.

6. The switch circuit of claim 1 , wherein the connection circuit further comprises at least one of a plurality of inductors and a plurality of resistors coupled to the switch module.

7. 2. The switch circuit of claim 1, wherein the connection circuit is coupled to each individual switch module of the switch modules at a node of the individual switch module between a rectifier and a capacitor of the individual switch module.

8. The switch circuit of claim 1 , wherein the power converter is coupled to the upper node.

9. The switch circuit of claim 1 , wherein the power converter is coupled to the lower node.

10. a first stacked switch circuit, a second stacked switch circuit, and an output node; 2. The switch circuit of claim 1, wherein the first stacked switch circuit constitutes a first portion of the switch module and the second stacked switch circuit constitutes a second portion of the switch module, and the output node is coupled between the first stacked switch circuit and the second stacked switch circuit.

11. 11. The switch circuit of claim 10, wherein the power converter is a first power converter and the switch circuit further comprises a second power converter, the first power converter coupled to the connection circuit and the upper node, and the second power converter coupled to the connection circuit and the lower node.

12. 2. The switch circuit of claim 1, further comprising: the power sink coupled to the power converter, the power sink comprising an alternating current (AC) power supply, and the switch circuit configured to output the recovered power from the power converter to the AC power supply.

13. 2. The switch circuit of claim 1, further comprising: the power sink coupled to the power converter, the power sink comprising at least one of a direct current (DC) power supply and a DC rail, and the switch circuit configured to output the recovered power from the power converter to at least one of the DC power supply or the DC rail.

14. 2. The switch circuit of claim 1, wherein the plurality of switch modules comprises a first stacked switch circuit, a second stacked switch circuit, and a midpoint node, the first stacked switch circuit constituting a first portion of the switch module and the second stacked switch circuit constituting a second portion of the switch module, the midpoint node being coupled between the first stacked switch circuit and the second stacked switch circuit, the first stacked switch circuit being configured to sustain a positive voltage between the upper node and the midpoint node in an off state, and the second stacked switch circuit being configured to sustain a positive voltage between the lower node and the midpoint node in an off state, and the switch circuit further comprises a power converter coupled to the midpoint node, a connection circuit of one of the first or second stacked switch circuits, and a capacitor of a switch module in the other of the first or second stacked switch circuits.

15. 1. A method comprising: applying a voltage across a plurality of switch modules connected in series between two terminal nodes comprising an upper node and a lower node, each of the switch modules comprising a switch, a rectifier and a capacitor; diverting power from the switch module through a connection circuit coupled to the switch module to a power converter coupled to the connection circuit and to a power sink, thereby limiting a component of voltage across one or more of the switches and recovering power from the voltage limit to the power sink; A method comprising:

16. 16. The method of claim 15, wherein applying a voltage across the plurality of switch modules comprises applying a voltage across a first stacked switch circuit comprising a first portion of the switch module, a second stacked switch circuit comprising a second portion of the switch module, and an output node coupled between the first stacked switch circuit and the second stacked switch circuit.

17. 16. The method of claim 15, wherein applying a voltage across the plurality of switch modules includes applying a voltage across a first stacked switch circuit constituting a first portion of the switch modules, a second stacked switch circuit constituting a second portion of the switch modules, and a midpoint node coupled between the first stacked switch circuit and the second stacked switch circuit, the first stacked switch circuit being capable of sustaining a positive voltage between the upper node and the midpoint node and the second stacked switch circuit being capable of sustaining a positive voltage between the lower node and the midpoint node; and connecting a power converter to the midpoint node, a connection circuit of one of the first or second stacked switch circuits, and a capacitor of a switch module in the other of the first or second stacked switch circuits.

18. 1. A computing system comprising: one or more processing devices, one or more tangible computer readable memory devices, and one or more tangible computer readable data storage devices; program instructions for configuring a switch circuit to apply a voltage across a plurality of switch modules connected in series between two terminal nodes comprising an upper node and a lower node, the program instructions being stored on the one or more data storage devices for execution by the one or more processing devices using the one or more memory devices, each of the switch modules comprising a switch, a rectifier, and a capacitor; program instructions for configuring the switch circuit to divert power from the switch module through a connection circuit coupled to the switch module to a power converter coupled to the connection circuit and to a power sink, thereby limiting a component of voltage within the switch circuit and recovering power from the voltage limitation to the power sink, the program instructions being stored on the one or more data storage devices for execution by the one or more processing devices using the one or more memory devices; A computing system comprising:

19. the program instructions for configuring the switch circuitry to apply a voltage across the plurality of switch modules comprising: program instructions for configuring the switch circuitry to apply a voltage across a first stacked switch circuit, a second stacked switch circuit, and an output node; the first stacked switch circuit constitutes a first portion of the switch module, the second stacked switch circuit constitutes a second portion of the switch module, and the output node is coupled between the first stacked switch circuit and the second stacked switch circuit.

20. The computing system of claim 18.

20. The program instructions for configuring the switch circuit to apply a voltage across the plurality of switch modules include: program instructions for configuring a first stacked switch circuit, a second stacked switch circuit, and the switch circuits to apply a voltage across a midpoint node, the program instructions comprising: the first stacked switch circuit constitutes a first portion of the switch module, the second stacked switch circuit constitutes a second portion of the switch module, and the midpoint node is coupled between the first stacked switch circuit and the second stacked switch circuit; the first stacked switch circuit is configured to sustain a positive voltage between the upper node and the midpoint node, and the second stacked switch circuit is configured to sustain a positive voltage between the lower node and the midpoint node. Program instructions; program instructions for configuring the power converter connected to the midpoint node, a connection circuit of one of the first or second stacked switch circuits, and a capacitor of the switch module in the other of the first or second stacked switch circuits to transfer power to a capacitor of a switch module; 20. The computing system of claim 18, comprising:

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