External adjustment of drive control of switches

Abstract

A control system for controlling a conductivity modulator device of a power switch array. The control system includes a system controller to sense a power event and output a command signal to adjust a drive characteristic of the conductivity modulator device in response to the sensed power event; and a switch controller configured to receive the command signal and control energy delivery to a load by controlling turn-on and turn-off of the conductivity modulator device. The switch controller includes an adjustable drive element to control a rise time and / or fall time of a voltage across the conductivity modulator device; and a drive characteristic control device to receive the command signal and change the drive characteristic by controlling the adjustable drive element to adjust the rise time and / or fall time of the voltage across the conductivity modulator device in response to the command signal.

Description

Technical Field

[0001] The present invention generally relates to switch controllers for semiconductor switches, and more specifically to switch controllers that can be controlled by a user or a system controller. Background Technology

[0002] Household and industrial appliances such as ventilation fans, cooling systems, refrigerators, dishwashers, washer / dryers, and many other white goods typically utilize electric motors that transfer energy from a power source to a mechanical load. Electrical energy for driving the electric motor is supplied through a drive system that draws power from a power source (e.g., from a low-frequency AC source). The electrical energy received from the power source is processed by a power converter and converted into the desired form of electrical energy supplied to the motor to achieve the desired mechanical output. The desired mechanical output of the motor can be, for example, the motor's speed, torque, or the position of the motor shaft.

[0003] Motors and their associated circuitry (such as motor drives) represent a significant portion of the load on utility networks. The functionality, efficiency, size, and price of motor drives are challenging and are competitive factors considered by suppliers of these products. The function of a power converter in a motor drive involves providing input electrical signals, such as voltage, current, frequency, and phase, to the motor to achieve a desired mechanical output load motion (e.g., rotation / force) on the motor shaft. In one embodiment, the power converter may be an inverter that delivers a direct current (DC) input to an AC output with the desired voltage, current, frequency, and phase, and typically includes one or more switches to control the energy transfer. Each switch in this power converter is controlled by a switch controller. Attached Figure Description

[0004] Non-limiting and non-exhaustive embodiments of the invention are described with reference to the following figures, wherein, unless otherwise stated, the same reference numerals refer to the same parts in all the various views.

[0005] Figure 1 This is a functional block diagram of a system controller with the driving characteristics of an adjustment switch according to an embodiment of this disclosure.

[0006] Figure 2A During a switch-on event, according to the implementation scheme of this disclosure. Figure 1 Timing diagrams of various waveforms in the system.

[0007] Figure 2B During a switch-off event, according to the implementation scheme of this disclosure. Figure 1 Another timing diagram of the various waveforms of the system.

[0008] Figure 3 is a functional block diagram of a system controller and a switch controller according to embodiments of the disclosure illustrating example commands from the system controller to adjust the switches. Figure 1 is a functional block diagram of a system controller and a switch controller according to embodiments of the disclosure illustrating example commands from the system controller to adjust the switches.

[0009] Figure 4 is a functional block diagram of a switch controller according to embodiments of the disclosure illustrating receiving commands from a user.

[0010] Figure 5A is a functional block diagram of a motor driver with a system controller to adjust one or more switches of individual half-bridge modules according to embodiments of the disclosure.

[0011] Figure 5B is a functional block diagram of a system controller and a half-bridge module according to embodiments of the disclosure. Figure 5A is a functional block diagram of a system controller and a half-bridge module according to embodiments of the disclosure.

[0012] Figure 6A is a functional block diagram of one embodiment of a power converter in a half-bridge configuration with a system controller to adjust one or more switches according to embodiments of the disclosure.

[0013] Figure 6B is a functional block diagram of another embodiment of a power converter in a half-bridge configuration with a system controller to adjust one or more switches according to embodiments of the disclosure.

[0014] Figure 6C is a functional block diagram of a system controller, an interface, and a switch controller according to embodiments of the disclosure. Figure 6A and Figure 6B is a functional block diagram of a system controller, an interface, and a switch controller according to embodiments of the disclosure.

[0015] In all of the several views of the drawings, corresponding reference characters indicate corresponding parts throughout the several views. Skilled artisans will appreciate that the elements in the figures are illustrated for simplicity and clarity and have not necessarily been drawn to scale. For example, the dimensions of some of the elements in the figures can be exaggerated relative to other elements to help improve the understanding of the present embodiments of the application. Also, common but well-understood elements that are useful in a commercially feasible embodiment have not been described or illustrated in order to avoid obscuring the concepts of the present application. DETAILED DESCRIPTION

[0016] In the following description, numerous specific details are set forth to provide a thorough understanding of the application. However, it will be apparent to one skilled in the art that the application can be practiced without the specific details. In other instances, well-known materials or methods have not been described in order to avoid obscuring the application.

[0017] References throughout this specification to "one embodiment", "an embodiment", "one example" or "an example" mean that a particular feature, structure, or characteristic described in connection with the embodiment or example is included in at least one embodiment of the application. The appearances of the phrases "in one embodiment", "in an embodiment", "one example" or "an example" in various places in the specification are not necessarily all referring to the same embodiment or example. Furthermore, the particular features, structures, or characteristics can be combined in any suitable

[0018] In the context of the present application, when a transistor is in an "off state" or "off", the transistor does not substantially conduct current. Conversely, when a transistor is in an "on state" or "on", the transistor significantly conducts current. For example, in one embodiment, a high voltage transistor comprises an N-channel metal-oxide-semiconductor field-effect transistor (NMOS) in which a high voltage is supported between a first terminal, i.e., drain, and a second terminal, i.e., source. In another embodiment, a high voltage transistor comprises an insulated-gate bipolar transistor (IGBT) in which a high voltage is supported between a first terminal, i.e., collector, and a second terminal, i.e., emitter. For the purposes of the present disclosure, "ground" or "ground potential" refers to a reference voltage or potential relative to which all other voltages or potentials of an electronic circuit or integrated circuit (IC) are defined or measured. In one embodiment, a transistor or switch can also be referred to as a conductivity-modulating device that can be controlled to conduct various amounts of current.

[0019] Inverters with half-bridge switching configurations are commonly used with motor drives. Instead of implementing a full-bridge switching configuration, utilizing a half-bridge switching circuit with a low-side control block and a high-side control block (also referred to as a low-side switch controller and a high-side switch controller) inside a single package (e.g., a module) allows for support of multi-phase inverters, such as single-phase and three-phase inverters, that provide increased layout flexibility and simplified thermal management for each module. For a variety of reasons, using a modular half-bridge circuit structure for a motor drive inverter can reduce overall system cost. Each switch of the half-bridge circuit structure is typically controlled by a switch controller, which in turn is controlled by a system controller. The switches are controlled by the switch controllers to regulate energy delivery in response to signals received from the system controller and / or a user.

[0020] Conductivity modulation devices, such as transistors, can be used for one or more switches in a power converter, such as an inverter. Typical losses associated with conductivity modulation devices are conduction losses and switching losses (also referred to as cross-over losses). Conduction losses are generated in response to a voltage across a conductivity modulation device when the conductivity modulation device is conducting current, in response to a current through the conductivity modulation device. Switching losses are typically associated with losses that occur when a conductivity modulation device transitions between an on state and an off state or between an off state and an on state.

[0021] Generally, a conductivity modulation device takes time to transition from an on state to an off state and from an off state to an on state in response to a drive signal provided to a control terminal of the conductivity modulation device. A control terminal of a field effect transistor (FET), an insulated gate bipolar transistor, or a silicon carbide (SiC)-based transistor is commonly referred to as a gate terminal. A control terminal of a bipolar junction transistor (BJT) is commonly referred to as a base terminal. The time for a conductivity modulation device to transition from an off state to an on state can be referred to as a turn-on time, while the time for a conductivity modulation device to transition from an on state to an off state can be referred to as a turn-off time. Switching / crossover losses occur during this transition time, and they can be reduced by reducing the turn-on time and the turn-off time. Additionally, shorter turn-on times and turn-off times generally correspond to reduced temperatures of the conductivity modulation device (and thus the system). However, shorter turn-on times and turn-off times also generally correspond to increased system-level electromagnetic interference (EMI). As such, there is generally a trade-off between EMI, switching losses, and temperature.

[0022] The duration of the turn-on time and turn-off time of the conductivity modulation device is related to the characteristics of the drive signal provided to the control terminal of the conductivity modulation device. It should be understood that the conductivity modulation device can be voltage controlled or current controlled at the gate terminal. Voltage controlled conductivity modulation devices will typically be controlled with a voltage source and a drive resistor (also referred to as a gate resistor), and the drive current for the conductivity modulation device is determined by the voltage drop across the control resistor. In other words, the value of the voltage source controls the drive characteristics of the conductivity modulation device. Current controlled conductivity devices can include a current source, and the drive current for the conductivity modulation device is determined by the charge delivered through the current source. In other words, the value of the current source controls the drive characteristics of the conductivity modulation device. In one embodiment, the drive signal is a current characterized by its amplitude, direction, and rate of change. The characteristics of the drive current determine the charge through the control terminal of the conductivity modulation device, and it is the charge that ultimately modulates the conductivity of the conductivity modulation device. A higher amplitude drive current corresponds to more charge at the control terminal in less time, resulting in shorter turn-on and / or turn-off times and lower switching / crossover losses. There can be conditions in a system such as a motor drive where the system controller can determine that there is a need to temporarily deliver more power to the load without exceeding the maximum allowable temperature of the switching device. The controller can reduce the turn-on and / or turn-off time of the switching device to provide the temporary increase in power. In addition, the system can be configured to tolerate higher electrical noise at times when higher power is required. In embodiments of the present invention, the characteristics of the drive for the conductivity modulation device can be adjusted by the system controller and / or the user through a switch controller and / or dedicated hardware sensors. The adjusted drive can increase or decrease the power delivered to the load within the bounds of other system parameters. In other words, the user and / or system controller can adjust the drive characteristics of the conductivity modulation device to meet changing requirements. This can be accomplished through a switch controller that includes a drive characteristic control that can receive a drive characteristic signal that represents one or more drive characteristics of the conductivity modulation device. In addition, in one embodiment, the conductivity modulation device can be adjusted in real-time by the system controller and / or the user, and as such, the drive characteristics of the conductivity modulation device can be adjusted according to demand to meet changing requirements.

[0023] Figure 1A system 100 having a system controller 102 with adjusted drive characteristics of a conductivity modulation device 106 is illustrated in accordance with an embodiment of the present disclosure. The system 100 includes the system controller 102 and a power switch array 104. The power switch array 104 can include one or more conductivity modulation devices. As illustrated, the power switch array 104 includes conductivity modulation devices 106, 108, 110, and 112. The conductivity modulation devices 106, 108, 110, and 112 are illustrated coupled together by dashed lines to emphasize that the power switch array 104 can be coupled in various configurations. For example, the conductivity modulation devices in the power switch array 104 can represent transistors of one or more inverters having a half-bridge switching configuration or other power converter topology. In another embodiment, the conductivity modulation devices in the power switch array 104 can represent invertor transistors having a full-bridge switching configuration.

[0024] Each of the conductivity modulation devices 106, 108, 110, and 112 is controlled by a switching controller, however for ease of illustration, only a switching controller 114 for the conductivity modulation device 106 is illustrated. The voltage across the conductivity modulation device 106 is shown as a voltage V DS 150 (also referred to as a drain-source voltage V DS 150), while the conduction current of the conductivity modulation device 106 is a current I D 148 (also referred to as a drain current I D 148). In the illustrated embodiment, the conductivity modulation device 106 is a current-controlled device. The control current for the conductivity modulation device 106 is shown as a current I G 146 (also referred to as a gate current I G 146). The conductivity modulation device can be a transistor, such as a metal-oxide-semiconductor field-effect transistor (MOSFET), a bipolar transistor, an injection-enhanced gate transistor (IEGT), an insulated-gate bipolar transistor (IGBT), and a gate turn-off thyristor (GTO). Further, the conductivity modulation device can be based on silicon (Si), gallium nitride (GaN), or silicon carbide (SiC) semiconductors.

[0025] The system controller 102 is coupled to the switch controller 114 through an interface 120. In one embodiment, the interface 120 galvanically isolates the system controller 102 from the switch controller 114. In another embodiment, the interface 120 does not galvanically isolate the system controller 102 from the switch controller 114. As shown, the system controller 102 receives a sensed signal 116 indicative of a power event. In one embodiment, the power event can be indicative of the system controller 102 providing increased power to a load, such as a motor. In one implementation, the sensed power event can be indicative of the system controller 102 adjusting a drive characteristic of the conductivity modulation device 106. In one embodiment, the system controller 102 adjusts the drive characteristic of the conductivity modulation device 106 by increasing an amplitude of a drive current (e.g., gate current I G 146) of the conductivity modulation device 106. Further, in one implementation, the system controller 102 adjusts the drive characteristic of the conductivity modulation device 106 by increasing the amplitude of the drive current during the on-time, the off-time, or both. In one embodiment, the drive current can also be referred to as drive strength, where a greater drive current amplitude corresponds to a greater drive strength. Or in other words, the power event can be indicative of the system controller 102 reducing the on-time and / or the off-time by increasing the amplitude of the gate current I G 146 to reduce the rise time and / or fall time of the drain current I D 148 of the conductivity modulation device 106. In some implementations, the power event can be indicative of the system controller 102 reducing the on-time and / or the off-time by increasing the amplitude of the gate current I G 146 to reduce the fall time and / or rise time of the drain-source voltage V DS 150. For example, the system controller 102 reduces the on-time and / or the off-time by modulating the values of the currents I EN and I DIS of the current sources 140 and 144. One embodiment of a sensed power event that increases the amplitude of the gate current I G 146 can include an outdoor air conditioner fan during start-up that can have to overcome possible wind conditions. Another embodiment of a sensed power event can include a dishwasher water pump that has to pump a large amount of water to prevent the dishwasher drain from being accidentally filled. Yet another embodiment of a sensed power event can include a refrigerator during an initial installation (also referred to as a cool-down period) to cool itself to a desired temperature.

[0026] In Figure 1In the illustrated embodiment, system controller 102 outputs command signal 118 to switch controller 114. In one embodiment, command signal 118 is output in response to a received sensing signal 116. Command signal 118 represents one or more commands from system controller 102 to switch controller 114 and one or more commands from switch controller 114 to system controller 102. In one embodiment, communication between system controller 102 and switch controller 114 is bidirectional. Example commands communicated through and / or to system controller 102 may include a “status query” command, in which system controller 102 sends a ping to switch controller 114 to obtain the “status” of switch controller 114, such as information stored in the status register of the switch controller. Another example command communicated by system controller 102 may include a “fault” command, in which switch controller 114 has sensed a fault condition (such as overcurrent, overvoltage, overheating, etc.) in system 100 and communicates the fault to system controller 102. Typically, switch controller 114 responds to a sensed fault by turning off conductivity modulator 106. Another example command conveyed by system controller 102 may include a “reset” command, wherein switch controller 114 is restarted or turned on. In embodiments of this disclosure, system controller 102 conveys adjustment commands indicating adjustments to one or more drive characteristics of conductivity modulation device 106. Example drive characteristics include those related to drain current I... D 148 and drain-source voltage V DS The gate current I related to the rise time and / or fall time of 150 G The amplitude (e.g., drive strength) of 146 can be modulated by the current I of current sources 140 and 144. EN and I DIS The value of I is used to change the gate current. G An amplitude of 146. Another example of drive characteristics may include that driven by the gate current I. G The duration of the drive conductivity modulation device 106 is 146. Another example of a drive characteristic may include the duration driven by the gate current I. G The frequency of the drive conductivity modulation device 106 is 146. For example, the gate current I... G 146 can be a pulse signal, which can be pulse width modulated (PWM) or pulse frequency modulated (PFM) in response to command signal 118. In some embodiments, command signal 118 can represent the gate current I... G 146's first amplitude or gate current I GThe conductance modulation device 106 is driven at a second amplitude, wherein the second amplitude is greater than the first amplitude. The command signal 118 can be a voltage signal or a current signal. In one embodiment, the command signal 118 can represent a digital word. Furthermore, the system controller 102 can apply encoding to the command signal 118.

[0027] Interface 120 receives command signal 118 and decodes / demodulates command signal 118 to output drive characteristic signal 128. In an embodiment, drive characteristic signal 128 represents one or more drive characteristics for conductivity modulator 106. Switch controller 114 also includes drive characteristic control device 122 and drive elements 124 and 126. As shown, interface 120 is coupled to drive characteristic control device 122 and outputs drive characteristic signal 128 to drive characteristic control device 122. Drive characteristic control device 122 is coupled to drive elements 124, 126 and controls drive elements 124, 126 to enable or disable (i.e., turn on or off) conductivity modulator 106. In an embodiment, drive characteristic control device 122 controls drive elements 124, 126 in response to drive characteristic signal 128. Furthermore, the drive characteristic control device 122 uses one or more drive characteristics provided by the drive characteristic signal 128 to control the drive elements 124, 126 to enable or disable (i.e., turn on or off) the conductivity modulation device 106. For example... Figure 1 As shown, the drive characteristic control device 122 outputs an enable signal EN 130 and a disable signal DIS 134 to turn the conduction modulator 106 on or off. In one embodiment, the enable signal EN 130 and the disable signal DIS 134 may be output via drive characteristic signal 128 in response to a command signal 118 from the system controller 102. In another embodiment, the enable signal EN 130 and the disable signal DIS 134 may be output in response to one or more signals separate from the command signal 118 received by the switch controller 114. Furthermore, the drive characteristic control device 122 may receive one or more signals separate from the command signal 118 and output an applicable enable signal EN 130 or disable signal DIS 134 to turn the conduction modulator 106 on or off.

[0028] As will be discussed further, in one embodiment, the drive characteristic control 122 adjusts the drive strength (e.g., drive current) of the conductivity modulation device 106 by adjusting the current provided by the drive elements 124, 126. As shown, the drive characteristic control 122 outputs an enable trim signal 132 and a disable trim signal 136 to the drive elements 124 and 126, respectively, that adjust the magnitude of the gate current I G 146 and the subsequent on-time and off-time of the conductivity modulation device 106.

[0029] The drive element 124 includes a switch 138 and a current source 140 having a current I EN to enable the conductivity modulation device 106. The current source 140 is coupled to the conductivity modulation device 106 to provide current to the control terminal (e.g., gate). The drive element 126 includes a switch 142 and a current source 144 having a current I DIS to disable the conductivity modulation device 106. The current source 144 is coupled to the conductivity modulation device 106 to sink current from the control terminal (e.g., gate). In some embodiments, the current sources 140 and 144 are trimmable current sources, where the current I EN and the magnitude of the current I DIS are responsive to the drive characteristic signal 128.

[0030] The drive characteristic control 122 is coupled to output the enable signal EN 130 and the enable trim signal 132 to the drive element 124. To enable the conductivity modulation device 106 to conduct (i.e., turn on), the drive characteristic control 122 outputs the enable signal EN 130 to turn on the switch 138 and turn off the switch 140. The current I EN is provided to the control terminal of the conductivity modulation device 106, and the magnitude of the gate current I G 146 of the conductivity modulation device 106 is substantially equal to the current I EN . In one embodiment, the enable signal EN 130 can be a rectangular pulse waveform having a logic high portion and a logic low portion of different lengths. The logic high portion can correspond to the switch 138 being on, and the logic low portion can correspond to the switch 138 being off (or vice versa). In one embodiment, the drive characteristic control 122 outputs the enable signal EN 130 responsive to a signal separate from the command signal 118 and the drive characteristic signal 128. The drive characteristic control 122 outputs the enable trim signal 132 to adjust the value of the current I EN , and thus the gate current IG 146. In embodiments of the present disclosure, the enable adjustment signal 132 is responsive to the drive characteristic signal 128. The enable adjustment signal 132 can be a voltage signal or a current signal, where the magnitude of the current I EN corresponds to the value of the enable adjustment signal. In one embodiment of the present disclosure, the enable adjustment signal 132 can adjust the value of the current I EN to a first current value I1or a second current value I2, although it is understood that the enable adjustment signal 132 can adjust the value of the current I EN to a plurality of current values. When the switch 138 is on and the current source 140 is providing current to the conductivity modulation device 106 while the switch 142 is off, the gate current I G 146 controls the fall time of the drain-source voltage VDS 150 and the turn-on time of the conductivity modulation device 106. As such, the system controller 102 can adjust the drive characteristics of the conductivity modulation device 106, such as the rise time of the drain current I D 148 and / or the fall time and turn-on time of the drain-source voltage V DS 150.

[0031] Similarly, the drive characteristic control 122 is coupled to output a disable signal DIS 134 and a disable adjustment signal 136 to the drive element 126. To disable the conductivity modulation device 106 from conducting (i.e., turn off), the drive characteristic control 122 outputs the disable signal DIS 134 to turn on the switch 142 and turn off the switch 138. The amount of current drawn from the control terminal of the conductivity modulation device 106 is limited by the value of the current IDIS provided by the current source 144. In one embodiment, the disable signal DIS 134 is a rectangular pulse waveform having a logic high portion or a logic low portion of different lengths. The logic high portion can correspond to the switch 142 being on, while the logic low portion can correspond to the switch 142 being off (or vice versa). In one embodiment, the disable signal DIS 134 is substantially the inverse of the enable signal EN 130. In one embodiment, the drive characteristic control 122 outputs the disable signal DIS 136 in response to a signal separate from the command signal 118 and the drive characteristic signal 128. The drive characteristic control 122 outputs the disable adjustment signal 136 to adjust the value of the current I DIS , and thus the magnitude of the gate current I G 146. In embodiments of the present disclosure, the disable adjustment signal 136 is responsive to the drive characteristic signal 128. The disable adjustment signal 136 can be a voltage signal or a current signal, where the magnitude of the current I DIS corresponds to the value of the disable adjustment signal 136. In one embodiment of the present disclosure, the disable adjustment signal 136 can adjust the value of the current IDIS The value is adjusted to either the first current value I1 or the second current value I2; however, it should be understood that disabling the adjustment signal 132 can reduce the current I. DIS The value is adjusted to multiple current values. Gate current I G 146 Amplitude-controlled drain current I D The fall time of 148 and the subsequent turn-off time of the conductivity modulator 106. Thus, the system controller 102 can adjust the drive characteristics of the conductivity modulator 106, such as the drain current I. D The descent time of 148 and the subsequent shutdown time.

[0032] In another embodiment, the drive characteristic control device 122 can adjust the drive characteristics of the conductivity modulation device 106 by pulse width modulation or pulse frequency modulation of the enable signal EN 130 or the disable signal DIS 134. By pulse frequency modulation or pulse frequency modulation of the enable signal EN 130 or the disable signal DIS 134, the drive characteristic control device 122 adjusts the gate current I. G The average amplitude is 146. Thus, the drain-source voltage V... DS 150 or drain current I D The rise time and / or fall time of 148 can be adjusted, and the subsequent turn-on and / or turn-off time of the conductivity modulation device 106 can be adjusted.

[0033] Figure 2A Examples are shown in Figure 1 During the turn-on transition of the conductivity modulator 106, the enable signal EN 130 and the gate current I G 146. Drain-source voltage V DS 150 and drain current I D Example timing diagram 200 for 148. Figure 2A The gate current I shown is G 146. Drain current I D 148 and drain-source voltage V DS The example waveform of 150 is approximated by a straight line. Furthermore, Figure 2A Examples are given for different drive intensities for gate current I. G 146. Drain current I D 148 and drain-source voltage V DS Example waveform 150. The example waveform on the right side of the page illustrates the provision of a larger drive current for the conductivity modulator 106 compared to the example waveform on the left side of the page.

[0034] In the illustrated embodiment, the enable signal EN 130 transitions from logic low to logic high to turn on switch 138 of drive element 124. Similarly, the disable signal (not shown) transitions from logic high to logic low to turn off switch 142. This enables conduction modulator 106 to conduct drive current I. D 148.

[0035] Once switch 138 is turned on (and switch 142 is turned off) via enable signal EN 130, the gate current I... G The current I from current source 140 is increased from 146. EN The amplitude. On the left side of the page, the current I of current source 140. EN It is basically equal to the first current value I1.

[0036] After switch 138 is turned on, the drain current I of conductivity modulation device 106 D The drain current ID 148 increases from zero with a slope of m1. In the illustrated embodiment, the drain current ID 148 increases to its peak value and then decreases to its conduction value. Figure 2A In the embodiment shown, once the drain current I D 148 reaches its peak value, and the drain-source voltage V of the conductivity modulation device 106 reaches its peak value. DS The voltage begins to decrease to zero at a slope of m2 from 150. The magnitudes of the slopes m1 and m2 are related to the gate current I. G The magnitude is related; for the embodiment on the left hand side, the gate current I... G The amplitude is basically equal to the current source I. EN The first current value I1 is 140. For the illustrated embodiment, the turn-on time 252 begins when the enable signal EN 130 transitions to a logic high value, and at the drain-source voltage V. DS The circuit ends when 150 is essentially zero, and the drain current I of the conductivity modulation device 106... D 148 has reached its conduction value.

[0037] On the right side of the page, the current I of current source 140 is... EN It is essentially equal to the second current value I2. As shown, the second current value I2 is greater than the first current value I1. Compared to the magnitudes of the slopes m1 and m2 shown on the left side of the page, the slope m1 (used for the drain current I) is greater. D 148) and m2 (for drain-source voltage V) DS The amplitude of 150) is larger. Thus, the drain current I D The rise time of 148 is shorter (and the drain-source voltage V148 is also shorter). DSThe shorter fall time of 150 results in a shorter overall turn-on time 254 for the operation of the conductivity modulation device 106 on the right-hand side compared to the turn-on time 252 shown on the left-hand side of the page. In other words, changing the current I of the current source 140... EN The value and the subsequent change in the gate current I of the conductivity modulator 106 G The value of 146 changes the on-time of the conductivity modulation device 106. This is used for the drain current I. D 148 and drain-source voltage V DS The shaded area under the waveform at 150 represents the crossover energy loss during the turn-on period of the conductivity modulator 106. As shown, the shaded area on the left-hand side of the page is larger than that on the right-hand side, indicating that the crossover loss of the conductivity modulator 106 on the left-hand side is greater than that on the right-hand side. A shorter turn-on time reduces switching / crossover losses, which also reduces heat dissipation and increases the amount of power delivered through system 100. However, a shorter turn-on time can lead to increased EMI.

[0038] Figure 2B Examples are shown in Figure 1 The conductance modulation device 106 disables the signal DIS 134 and gate current I during the turn-off transition. G 146. Drain-source voltage V DS 150 and drain current I D Example timing diagram 201 for 148. Similar to... Figure 2A The diagram shown is for the gate current I G 146. Drain current I D 148 and drain-source voltage V DS The example waveform of 150 is approximated by a straight line. Furthermore, Figure 2B Examples are given for different drive intensities for gate current I. G 146. Drain current I D 148 and drain-source voltage V DS Example waveform 150. The gate current I is shown on the right side of the page. G 146. Drain current I D 148 and drain-source voltage V DS The example waveform at 150 has a larger value than the one shown on the left-hand side of the page for the gate current I. G 146. Drain current I D 148 and drain-source voltage V DS The example waveform of 150 has a larger drive current.

[0039] The disable signal DIS 134 transitions from logic low to logic high to turn on switch 142 of drive element 126. Similarly, the enable signal (not shown) transitions from logic high to logic low to turn off switch 138. This disables the conduction modulation device 106 from conducting drive current I. D 148.

[0040] Once switch 142 is turned on (and switch 138 is turned off) via the disable signal DIS 134, the gate current I... G The amplitude of 146 is basically the current I of the current source 144. DIS The magnitude. For Figure 1 The drive element 126 shown, once switch 142 is turned on (and switch 138 is turned off), the gate current I... G The current flows from 146 back to 127. This is due to the direction of the current. Figure 2B The gate current I shown G 146 decreased. Furthermore, the gate current I... G The maximum amplitude response of 146 is to the current I of current source 144. DIS The amplitude. On the left side of the page, the current I of current source 144. DIS It is basically equal to the first current value I1.

[0041] After switch 142 is turned on, the drain-source voltage V of conductivity modulation device 106 DS The voltage increases from zero with a slope of m2, starting at 150. For the illustrated embodiment, once the drain-source voltage V... DS 150 has reached its peak, and the drain current I of the conductivity modulation device 106 is... D 148 then decreases to zero with a slope m1. The magnitudes of slopes m1 and m2 are related to the gate current I. G The magnitude is related; for the embodiment on the left hand side, the gate current I... G The amplitude is basically equal to the current source I. DIS The first current value I1 of 144. For the illustrated embodiment, the turn-off time 256 begins when the disable signal DIS 134 transitions to a logic high value, and when the drain current I... D 148 ends when it is essentially zero, and the drain-source voltage V of the conductivity modulation device 106... DS 150 has reached its non-conductive value.

[0042] On the right side of the page, the current I of current source 144 is... DIS It is essentially equal to the second current value I2. As shown, the second current value I2 is greater than the first current value I1. Compared to the magnitudes of the slopes m1 and m2 shown on the left side of the page, the slope m1 (used for the drain current I) is greater.D 148) and m2 (for drain-source voltage V) DS The amplitude of 150) is larger. Thus, the drain current I D The 148 has a shorter fall time (and a shorter drain-source voltage V). DS The shorter rise time of 150 results in a shorter overall turn-off time 258 for the operation of the conductivity modulation device 106 on the right-hand side, compared to the turn-off time 256 shown on the left-hand side of the page. In other words, changing the current I of the current source 144... DIS The value and the subsequent change in the gate current I of the conductivity modulator 106 G A value of 146 shortens the turn-off time of the conductivity modulation device 106. This is used for the drain current I. D 148 and drain-source voltage V DS The shaded area under the waveform at 150 represents the cross-loss during the turn-on period of the conductivity modulator 106. As shown, the shaded area on the left-hand side of the page is larger than that on the right-hand side, indicating that the cross-loss of the conductivity modulator 106 on the left-hand side is greater than that on the right-hand side. Shorter turn-off times reduce switching / cross-loss, which also reduces heat dissipation and increases the amount of power delivered by the system 100.

[0043] Figure 3 yes Figure 1 The functional block diagram of system controller 102 and switch controller 114 illustrates example command signals 118 from the system controller for adjusting the conductivity modulator 106 and / or switch controller 114. It should be understood that system controller 102, switch controller 114 and their respective components are coupled and function as described above.

[0044] As shown, command signal 118 is a rectangular pulse waveform with high and low portions. As will be discussed, the duration of the low portion corresponds to which command the system controller 102 is transmitting, referred to as the effective low pulse duration encoding. Under default or steady-state conditions, when no command is being transmitted, command signal 118 is substantially equal to the high value. In one embodiment, the high value may be substantially 5 volts (V). When system controller 102 transmits a command to switch controller 114 via command signal 118, the command signal transitions to a low value. In one embodiment, the low value may be substantially 0V. The duration of the low portion of command signal 118 corresponds to which command the system controller 102 is transmitting. Figure 3The example command signal 118 in the illustrated embodiment is a "valid low" signal, where the duration of the low portion corresponds to which command is being transmitted. However, it should be understood that the command signal 118 can be a "valid high" signal, where the duration of the high portion corresponds to which command is being transmitted.

[0045] For example, the first command 360 corresponds to the command signal 118 being substantially low for a time period T. For the second command 361, the command signal 118 can be substantially low for a time period 2T. In the illustrated embodiment, the low portion of the second command 361 is twice as long as the low portion of the first command 360. Similar for the third command 362 and the fourth command 363. For the third command 362, the command signal 118 can be substantially low for a time period 3T, which is three times as long as the low portion of the first command 360. For the fourth command 363, the command signal 118 can be substantially low for a time period 4T, which is four times as long as the low portion of the first command 360. In other words, the duration of each command can be longer than the duration of the previous command by a time period T. In one embodiment, the interface 120 can include a timer or counter to measure the duration of the low portion in the command signal 118 to determine which command has been received.

[0046] The example commands can include: a status query, a reset, an increase drive current, and a decrease drive current. The increase drive current command and the decrease drive current command are adjustment commands / signals to adjust the drive characteristics of the conductivity modulation device 106. For the first command 360, the system controller 102 can send a "status query" command, where the system controller 102 sends information to the switch controller 114 to get the "status" of the switch controller 114, such as information stored in a status register of the switch controller.

[0047] For the second command 361, the system controller 102 can send a "reset" command, where the system controller 102 allows the switch controller 114 to be restarted or turned on.

[0048] For the third command 362, the system controller 102 can send an adjustment command to "increase drive current", where the system controller 102 instructs the switch controller 114 that the current I EN or the current I DIS of the current source 144, or both, to decrease the rise time of the drain current I D 148 or the fall time of the drain current I D 148 or both (i.e., the fall time of the drain-source voltage V DS 150 or the fall time of the drain-source voltage V DSThe rise time or both of 150° are reduced. A reduced rise time or fall time will shorten the on-time or off-time of the conductivity modulator 106, respectively. Under normal operating conditions, the drive characteristic control device 122 outputs an enable adjustment signal 132 and a disable adjustment signal 136, causing the current I of the current source 140 to... EN and the current I of current source 144 DIS Basically equal to ( Figure 2A and 2B The first current value I1. In one embodiment, the system controller 102 outputs a third command 362 in response to a sensing signal 115, which indicates that a power event exists in the system 100 in which the system controller 102 may want to deliver more power. In response to the third command 362, the drive characteristic control device 122 may output an enable adjustment signal 132 or a disable adjustment signal (or both) to reduce the current I of the current source 140. EN Or the current I of current source 144 DIS (or both) values ​​are adjusted to the second current value I2 (e.g.) Figure 2A and 2B (as shown in the figure), and increases the drive current of the conductivity modulation device 106.

[0049] For the fourth command 363, system controller 102 can send an adjustment command to "reduce drive current" (or in other words, "return drive current" command), wherein system controller 102 instructs switch controller 114 to reduce (or return) the current I of current source 140. EN Or the current I of current source 144 DIS Or both, to increase the drain current I D 148 rise time or drain current I D The fall time of 148 or both (i.e., increasing the drain-source voltage V) DS 150° fall time or drain-source voltage V DS (Rise time of 150 or both). Or in other words, system controller 102 instructs switch controller 114 to switch the current I from current source 140 to current source 140. EN Or the current I of current source 144 DIS Or the values ​​of both are returned to Figure 2A and 2B The first current value I1. In one embodiment, the sensing signal 115 indicates to the system controller 102 that the increased power event in the system 100 has passed. In response to the fourth command 363, the drive characteristic control device 122 may output an enable adjustment signal 132 or a disable adjustment signal (or both) to reduce the current I of the current source 140. EN Or the current I of current source 144 DIS (or both) values ​​adjusted toFigure 2A and 2B The first current value I1 is set, and the drive current of the conductivity modulation device 106 is reduced (or returned) to its default current value. Although for this embodiment, the commands: status query, reset, increase drive current, and decrease drive current are respectively the first command 360, the second command 361, the third command 362, and the fourth command 363, it should be understood that the commands can be in any order.

[0050] In some implementations, communication between system controller 102 and switch controller 114 can be bidirectional. For example, switch controller 114 can sense fault conditions (such as overcurrent, overvoltage, overheating, etc.) in system 100 and transmit the fault to system controller 102. The fault transmission from switch controller 114 can be encoded as a multi-bit word to system controller 102.

[0051] Figure 4 An embodiment of a switch controller 114 according to this disclosure is illustrated, which receives a command signal 118 in response to a toggle 465. In one embodiment, the toggle 465 may be responsive to a user. In another embodiment, the toggle 465 may be responsive to a dedicated hardware sensor that senses a power event. It should be understood that the switch controller 114 and its components are coupled and function as described above. In one embodiment, the switch controller 114 may receive commands from both a system controller (not shown) and the toggle 465. In another embodiment, the switch controller 114 receives the command signal 118 only in response to the toggle 465.

[0052] User 465 can be a rectangular pulse waveform with a logic high portion and a logic low portion. In one implementation, flip-flop 465 represents manual selection by the user from two options, such as a mechanical switch. The logic low value used for flip-flop 465 corresponds to a drain current I that is substantially equal to the first value. D Rise time / fall time of 148 (drain-source voltage V) DS (rise time / fall time of 150), such as, for example, gate current I G 146 is basically equal to the first current value I1, such as Figure 2A and 2B As shown, the logic high value used for flip-flop 465 can correspond to a drain current I that is substantially equal to the second value. D Rise time / fall time of 148 (drain-source voltage V) DS (rise time / fall time of 150), such as, for example, gate current I G 146 is basically equal to the second current value I2, such as Figure 2A and 2B As shown in the figure.

[0053] As shown in one embodiment, transistor 464 is coupled to interface 120 and return 127 of switch controller 114. The control terminal of transistor 464 is configured to receive flip-flop 465. In the illustrated embodiment, transistor 464 is a bipolar junction transistor (BJT). The base of transistor 464 is configured to receive flip-flop 465, the emitter of transistor 464 is coupled to return 127, and the collector of transistor 464 is coupled to interface 120. For the illustrated embodiment, command signal 118 is a voltage signal and is the collector voltage or collector-emitter voltage of transistor 464. In operation, when flip-flop 465 is low, transistor 464 is off and command signal 118 is high. As such, the high value for command signal 118 corresponds to a drain current I D 148 substantially equal to the first value. When flip-flop 465 is high, transistor 464 is on and command signal 118 is substantially equal to return 127 (i.e., low value). As such, the low value for command signal 118 corresponds to a drain current I DS 148 substantially equal to the second value. D 150. DS

[0054] Figure 5A A multi-phase motor drive system 500 is illustrated that includes three half-bridge inverter modules 566, 567, and 568 that are individually coupled to a high voltage (HV) bus 576 and controlled with a single system controller 102 to drive a motor 569, such as, for example, a single or three phase motor. As shown, each half-bridge inverter module 566, 567, and 568 and system controller 102 are referenced to return 127. Further, in accordance with the teachings of the present disclosure, system controller 102 can adjust the drive characteristics of one or more switches of each half-bridge inverter module 566, 567, and 568. As shown, each switch is represented by an n-type metal oxide semiconductor field effect transistor (MOSFET) and is a conductivity modulated device as discussed above.

[0055] ​Each half-bridge module 566, 567, 568 is individually coupled to the HV bus 576. Each half-bridge module 566, 567, 568 includes one high-side switch 570, 571, 572 and one low-side switch 573, 574, 575, which are coupled together as a power converter or inverter in a full-bridge configuration. Each switch 570, 571, 572, 573, 574, and 575 is controlled by its own switch controller (further shown in Figure 5B

[0056] The system controller 102 is coupled to each half-bridge module 566, 567, and 568 through a communication bus 577. Similar to above, in an implementation, the system controller 102 receives a sensed signal 116 indicative of a power event. In one implementation, the power event can be indicative of the system controller 102 adjusting one or more drive characteristics of one or more of the switches 570, 570, 571, 572, 573, 574, and 575. For the implementation, the system controller adjusts a drive current of one or more of the switches 570, 570, 571, 572, 573, 574, and 575 in response to the sensed power event 116. Or in other words, the power event can be indicative of the system controller 102 increasing the rise time and / or fall time of the gate current I G 146 of one or more of the switches 570, 570, 571, 572, 573, 574, and 575 to decrease the switching on time and / or off time. Increasing the gate current I D 146 of one or more of the switches 570, 570, 571, 572, 573, 574, and 575 to decrease the switching on time and / or off time. Increasing the gate current I G ​One embodiment of a sensed power event of the magnitude 146 can include an outdoor air conditioning fan during start-up that can have to overcome possible wind conditions. Another embodiment of a sensed power event can include a dishwasher water pump that has to pump a large amount of water to prevent the dishwasher drain from being accidentally filled. Yet another embodiment of a sensed power event can include a refrigerator during initial installation to cool itself to a desired temperature.

[0057] The system controller 102 is configured to output command signals to one or more half-bridge modules 566, 567, and 568. In one embodiment, the system controller 102 can send command signals via a communication bus 577. In another embodiment, the system controller 102 sends command signals via separate connections. The command signals 118 can be voltage signals or current signals. In one embodiment, the command signals 118 can represent digital words. Further, the system controller 102 can apply encoding to the command signals 118. As will be further illustrated, the system controller 102 can output command signals 118 to at least one switch controller in one or more half-bridge modules 566, 567, and 568 via the communication bus 577. In one embodiment, the command signals are output in response to received sensed signals 116, and the command signals can represent commands of the system controller 102 for the corresponding switch controller. Example commands communicated by the system controller 102 can include a "status query" command for one or more of the half-bridge modules 566, 567, and 568. Another example command communicated with the system controller 102 can include a "fault" command, where the system controller 102 has sensed a fault condition in the system 100 (such as overcurrent, overvoltage, overheat, etc.) and communicates the fault to the half-bridge modules 566, 567, and 568. Typically, the half-bridge modules 566, 567, and 568 respond to the fault command by turning off their respective high-side and low-side switches. Figure 5B Further illustrated, the system controller 102 outputs command signals 118 to at least one switch controller in one or more half-bridge modules 566, 567, and 568 via the communication bus 577. In one embodiment, the command signals are output in response to received sensed signals 116, and the command signals can represent commands of the system controller 102 for the corresponding switch controller. Example commands communicated by the system controller 102 can include a "status query" command for one or more of the half-bridge modules 566, 567, and 568. Another example command communicated with the system controller 102 can include a "fault" command, where the system controller 102 has sensed a fault condition in the system 100 (such as overcurrent, overvoltage, overheat, etc.) and communicates the fault to the half-bridge modules 566, 567, and 568. Typically, the half-bridge modules 566, 567, and 568 respond to the fault command by turning off their respective high-side and low-side switches.

[0058] In embodiments of the present disclosure, the system controller 102 communicates command signals 118 that represent drive characteristics of one or more of the high-side switches 570, 571, 572 and the low-side switches 573, 574, and 575. Example drive characteristics include a gate current Ig G 146 of the magnitude, a gate current Ig G 146 of the magnitude, and a drain-source voltage V D 148 of the magnitude. Another example drive characteristic can include a rise time and / or fall time of the gate current Ig G146the duration of one or more of the switches 570, 571, 572, 573, 574, and 575. For example, a command communicated via the communication bus 577 can indicate driving one or more of the switches 570, 571, 572, 573, 574, and 575 at a first amplitude of the gate current I G or a second amplitude of the gate current I G , where the second amplitude is greater than the first amplitude. It is to be understood, however, that the command signal 118 can indicate driving one or more of the switches 570, 571, 572, 573, 574, and 575 at more than two amplitudes of the gate current I G .

[0059] The half-bridge modules 566, 567, and 568 are coupled to the communication bus 577, which is also coupled to the system controller 102. In one embodiment, the communication bus 577, which is in an open-collector configuration, is coupled to the supply voltage V UP by an upper pull resistor R UP . Further, in one embodiment, the communication bus 577 can be a single-wire communication bus. As mentioned above, the communication bus 577 can be utilized by the system controller 102 to communicate commands to one or more of the half-bridge modules 566, 567, and 568. In one embodiment, the communication bus 577, in a normal steady state, is pulled up to the supply voltage V UP , and can be pulled down by the system controller 102 during any communication for sending commands to the half-bridge modules 566, 567, and 568. In one implementation, the communication bus 577 can be pulled down for detection of commands by a digital multi-bit word. In another implementation, the communication bus 577 can be pulled down to communicate commands, as discussed with respect to Figure 3 . In some implementations, the duration of the communication bus 577 being pulled down corresponds to the command sent by the system controller 102.

[0060] Figure 5B Increased details of the half-bridge module are provided in accordance with embodiments of the present disclosure. Specifically, Figure 5B the half-bridge module 566 is illustrated, but it is to be understood that the other half-bridge modules 567, 568 are present, but not shown in detail. Further, the elements included in the half-bridge modules 567, 568 are similar to the elements shown with respect to the half-bridge module 566 in Figure 5B .

[0061] The half-bridge module 566 includes a high-side switch 570 and a low-side switch 537 coupled together in series. The high-side switch 570 and the low-side switch 537 are illustrated as n-type MOSFETs with respective body diodes. The drain of the high-side switch 570 is coupled to the HV bus 576, and the source of the low-side switch 573 is coupled to the return 127. The half-bridge midpoint HB1 is coupled to phase A of the motor 569.

[0062] The half-bridge module 566 also includes the switch controller 114 and 515. The switch controller 114 is coupled to control the low-side switch 573, and the switch controller 515 is coupled to control the high-side switch 570. As discussed above and in accordance with embodiments of the present disclosure, both the switch controllers 114, 515 include drive characteristic control devices for their respective switches. The switch controllers 114 and 515 can also include interfaces to receive the command signal 118, as will be further discussed. Similar to above, the switch controllers 114, 515 control the enablement and disablement of their respective switches as well as the on-time and off-time. In addition, the switch controllers 114, 515 can adjust the drive characteristics of the low-side switch 573 and the high-side switch 570, respectively, in response to the system controller 102.

[0063] The system controller 102 is coupled to the half-bridge module 566 and the switch controller 114. As illustrated, the system controller 102 outputs the command signal 118 to the switch controller 114. In response to the command signal 118 received from the system controller 102, the switch controller 114 adjusts the drive characteristics of the low-side switch 537. In one embodiment, an interface (not shown) of the switch controller 114 receives the command signal 118 and outputs a drive characteristic signal to the drive characteristic control device of the switch controller 114. The drive characteristic control device then outputs a signal to the drive elements that enable and disable the low-side switch 573. The system controller 102 can send the command signal 118 via the communication bus 577 or through another coupling to the switch controller 114.

[0064] As illustrated in dashed lines, in some embodiments, the system controller 102 can optionally be coupled to the switch controller 515 to provide the command signal 118 instead of providing the command signal 118 via the switch controller 114. In response to the command signal 118, the switch controller 515 adjusts the drive characteristics of the high-side switch 570. In one embodiment, an interface (not shown) of the switch controller 515 receives the command signal 118 and outputs a drive characteristic signal to the drive characteristic control device of the switch controller 515. The drive characteristic control device then outputs a signal to the drive elements that enable and disable the high-side switch 570. The system controller 102 can send the command signal 118 through another coupling to the switch controller 515 or via the communication bus 577.

[0065] In another alternative embodiment, shown by the dashed lines, the switch controller 114 is coupled to the switch controller 515. The switch controller 114 sends the received command signal 118 or the drive characteristic signal 128 to the switch controller 515, rather than the switch controller 515 receiving the command signal 118 from the system controller 102. Communication from the low-side switch controller 114 to the high-side switch controller 515 can be achieved through a communication link between the low-side switch controller 114 and the high-side controller 515. For example, the control signal for controlling both the high-side switch 570 and the low-side switch 573 can be received by the low-side switch controller 114 from the system controller 102. The control signal for the switch high-side switch 570 can be communicated from the low-side switch controller 114 to the high-side controller 515 via the communication link.

[0066] In one embodiment, the low-side switch controller 114 relays the command signal 118 received from the system controller 102 to adjust the drive characteristics, such as the high-side drive current, of the high-side switch 570 to the high-side switch controller 515. For this embodiment, the high-side switch controller 515 includes an interface (not shown) to receive the command signal 118 from the low-side switch controller 114 and outputs a drive characteristic signal to the drive characteristic control of the switch controller 515. The drive characteristic control then outputs a signal to the drive elements that enable and disable the high-side switch 570.

[0067] In another embodiment, the low-side switch controller 114 receives the command signal 118 at an interface (not shown) to adjust the drive characteristics, such as the high-side drive current, of the high-side switch 570. The interface (not shown) outputs a drive characteristic signal 128 to adjust the drive characteristics of the high-side switch 570 and the drive characteristic signal 128 of the low-side switch controller 114 is communicated to the high-side switch controller 515. For this embodiment, the high-side switch controller 515 includes its own drive characteristic control that is coupled to the low-side switch controller 114 and receives the drive characteristic signal 128 of the low-side switch controller 114. The drive characteristic control of the switch controller 515 then outputs a signal to the drive elements that enable and disable the high-side switch 570.

[0068] Figure 6A An example power converter 600 having a switch controller 114, 615 including a drive characteristic control is illustrated in accordance with embodiments of the present disclosure. The switch controller 114, 615 includes a drive characteristic control responsive to the system controller 102. Further, in accordance with embodiments of the present disclosure, the system controller 102 can adjust the drive characteristics of the switches 679, 680. The power converter 600 receives an input voltage V IN602, and is designed to transfer energy from the input to the load 682 through the energy transfer element LI 681 by controlling the switches of the power switches 679, 680. In various implementations, the power converter 600 can control the voltage, current, or power level of the energy output to the load 682. In Figure 6A In the embodiment shown in FIG. 6, the energy transfer element LI 681 and the two power switches 679, 680 are coupled together in a half-bridge configuration, although other topologies can be used. The power switches 679, 680 form a power switch array. The switch controller 114 can be referred to as a low-side switch controller, while the switch controller 615 can be referred to as a high-side switch controller.

[0069] In the embodiment shown, the power switches 679, 680 are IGBTs. However, embodiments of the present application can also be used in conjunction with other power switching technologies. For example, metal oxide semiconductor field effect transistors (MOSFETs), bipolar transistors, injection enhanced gate transistors (IEGTs), and gate turn-off thyristors (GTOs) can be used. Additionally, the power converter 600 can be used with power switches based on gallium nitride (GaN) semiconductors or silicon carbide (SiC) semiconductors.

[0070] The system controller 102 is coupled to receive system inputs 699, sense signals 116, and provide command signals 118. The system controller 102 determines whether the switch controllers 114, 615 should turn on or turn off the power switches 679, 680 based on the system inputs 699. Example system inputs 699 include a pulse width modulation (PWM) signal for a general purpose motor driver, an on and off sequence for a multi-level power converter, or a system fault shutdown request. The sense signals 116 are also system inputs, and in one implementation represent a power event. In one implementation, the power event can be an indication for the system controller 102 to adjust the drive characteristics of the power switch 679 or the power switch 680 or both. In one embodiment of adjusting the drive characteristics of either of the power switches 679, 680, the power event can be an indication to increase the drive current of either of the power switches 679, 680 or both. Or in other words, the power event can indicate to the system controller 102 to reduce the on time and / or the off time by increasing the rise time and / or the fall time of the current conducted by either of the power switches 679, 680 or both by increasing the amplitude of the control current for either of the power switches 679, 680 or both.

[0071] In the illustrated embodiment, the system controller 102 outputs command signals 118 representing one or more commands to the interface 120 of the switch controller 114, 615. Example commands include enabling or disabling the power switches 679, 680, a reset, a fault notification, and adjusting the drive current of the power switches 679, 680 (i.e., the rise and / or fall times of the conduction current). The command signals 118 can be voltage signals or current signals. In one embodiment, the command signals 118 can represent N-bit digital words. Further, the system controller 102 can apply encoding to the command signals 118. In one embodiment, the communication between the system controller 102 and the interface 120 can be bidirectional.

[0072] The interface 120 is coupled to the system controller 102 and receives the command signals 118. Figure 6A A single interface 120 is illustrated for both the switch controller 114, 615. However, it should be understood that each switch controller 114, 615 can have its own interface, and as such, the system controller 102 would output command signals 118 to both interfaces. Both the interface 120 and the system controller 102 are referenced to the primary reference potential 683, while the switch controller 114 is referenced to the secondary reference potential 684, and the switch controller 615 is referenced to the secondary reference potential 685. The secondary reference potentials 684, 685 are different potentials. In one embodiment, the reference potential 685 is coupled to the half-bridge point between the high-side switch 679 and the low-side switch 680, while the reference potential 684 is coupled to the emitter of the low-side switch 680. The switch controllers 114, 615 are galvanically isolated from the interface 120 by the isolation communication link 678. The isolation communication link 678 can be implemented as an inductive coupling, such as a signal transformer or a coupling inductor, an optical coupling, or a capacitive coupling. Further, the switch controllers 114, 615 can communicate bidirectionally with the interface 120 via the communication link 678.

[0073] The interface 120 interprets the command signals 118 sent by the system controller 102 and sends drive characteristic signals to the switch controllers 114, 615 to drive the power switches 679, 680, and further to adjust the drive current of the power switches 679, 680. The switch controllers 114, 615 receive their respective drive characteristic signals and generate drive signals to control the power switches 670, 680. As discussed above, the switch controllers 114, 615 include drive characteristic control means circuits and enable and disable drive elements to control the drive current (i.e., drive strength) of the power switches 680, 679. As such, the system controller 102 adjusts the drive strength of the power switches 680, 679.

[0074] Figure 6BAnother embodiment of a power converter 601 in a half-bridge configuration with a system controller 102 to adjust the drive characteristics, such as, for example, drive current, of the power switches 679, 680 is illustrated. It should be understood that the power converter 601 shares many similarities with the power converter 600 illustrated in Figure 6B Figure 6B For the embodiment illustrated in FIG. 6, the interface 120 interprets the command signal 118 and outputs a drive characteristic signal 128 to the switch controller 114. The switch controller 114 sends the drive characteristic signal 128 to the switch controller 615, rather than the switch controller 815 receiving the drive characteristic signal from the interface 120. Communication from the low-side switch controller 114 to the high-side switch controller 615 can be achieved through a communication link between the low-side switch controller 114 and the high-side controller 615. For this embodiment, the high-side switch controller 615 includes its own drive characteristic control device that is coupled to the low-side switch controller 114 and receives the drive characteristic signal 128 of the low-side switch controller 114. The drive characteristic control device of the switch controller 615 then outputs a signal to the drive elements that enable and disable the high-side switch 679.

[0075] Figure 6C An example isolation communication link 678 is illustrated. For simplicity, only the isolation communication link 678 between the interface 120 and the switch controller 114 is shown. The interface 120 and the system controller 102 are referenced to the primary reference potential 683, while the switch controller 114 is referenced to the secondary reference potential 684. The switch controller 114 is galvanically isolated from the interface 120 through the isolation communication link 678. The illustrated isolation communication link 678 is a signal transformer with a primary winding 687 and a secondary winding 689. The interface 120 is coupled to the primary winding 687 and outputs the drive characteristic signal 128. The switch controller 114 is coupled to the secondary winding 689 and receives the drive characteristic signal 128 multiplied by the turns ratio of the primary winding 687 to the secondary winding 689.

[0076] The above description of the illustrated embodiments of the application, including what is described in the Abstract, is not intended to be exhaustive or to be limiting to the precise forms disclosed. While specific embodiments of, and examples for, the application are described herein for illustrative purposes, various equivalent modifications are possible within the scope of the application, as those skilled in the relevant art will recognize. Indeed, it should be understood that the specific example voltages, currents, frequency, power range values, times, etc. are provided for explanation and not to limit other implementations and embodiments of the application that can be employed in other environments. ​

[0077] While the application is defined in the claims, it should be understood that the application can be alternatively defined in accordance with the following embodiments:

[0078] Embodiment 1. A control system configured to control a conductivity modulation device of a power switch array, the conductivity modulation device configured to control energy delivery to a load, the control system comprising: a system controller configured to sense a power event in the control system and output a command signal to adjust a drive characteristic of the conductivity modulation device in response to the sensed power event; and a switch controller coupled to the system controller and configured to receive the command signal, the switch controller further configured to control energy delivery to the load by controlling turn-on and turn-off of the conductivity modulation device, wherein the switch controller comprises: an adjustable drive element configured to control a rise time and / or a fall time of a voltage across the conductivity modulation device; and a drive characteristic control device configured to receive the command signal and vary the drive characteristic of the conductivity modulation device, the drive characteristic control device further configured to vary the adjustable drive element to adjust the rise time and / or the fall time of the voltage across the conductivity modulation device in response to the command signal generated by the system controller.

[0079] Embodiment 2. The control system of embodiment 1, the drive characteristic control device configured to adjust a rise time and / or a fall time of a current conducted by the conductivity modulation device.

[0080] Embodiment 3. The control system of embodiment 1 or 2, wherein the adjustable drive element comprises: a switch coupled to the drive characteristic control device, the switch configured to turn on or turn off to enable or disable conduction of a current through the conductivity modulation device; and a tunable current source coupled to the drive characteristic control device and coupled in series with the switch, the drive characteristic control device further configured to control a current provided by the tunable current source to vary the rise time and / or the fall time of the voltage across the conductivity modulation device in response to the command signal.

[0081] Embodiment 4. The control system of any one of embodiments 1 to 3, the drive characteristic control device further configured to control a current provided by the tunable current source to vary a rise time and / or a fall time of a current conducted by the conductivity modulation device.

[0082] Embodiment 5. The control system of any one of embodiments 1 to 4, wherein the drive characteristic control device is further configured to control an amplitude of the current provided by the tunable current source.

[0083] Example 6. The control system of any of Examples 1-5, wherein the drive characteristic control is further configured to control a duration of the current provided by the adjustable current source.

[0084] Example 7. The control system of any of Examples 1-6, wherein the drive characteristic control is further configured to control a frequency of the current provided by the adjustable current source.

[0085] Example 8. The control system of any of Examples 1-7, wherein the switch controller further comprises an interface coupled to the system controller and configured to receive a command signal, the interface further configured to interpret the command signal and output a drive characteristic signal to the drive characteristic control to adjust a rise time and / or fall time of the conductivity modulation device.

[0086] Example 9. The control system of any of Examples 1-8, wherein the interface is galvanically isolated from the drive characteristic control.

[0087] Example 10. The control system of any of Examples 1-9, wherein the control system controls energy delivery to a motor.

[0088] Example 11. The control system of any of Examples 1-10, wherein the conductivity modulation device is a transistor.

[0089] Example 12. The control system of any of Examples 1-11, wherein the command signal is a rectangular pulse waveform having a logic high portion and a logic low portion, wherein a duration of the logic low portion corresponds to a command of the command signal.

[0090] Example 13. The control system of any of Examples 1-12, wherein the system controller is configured to output the command signal to adjust the conductivity modulation device according to demand.

[0091] Example 14. A control system configured to control a conductance modulation device configured to control energy delivery to a load, the control system comprising: a system controller configured to sense a power event in the control system and to assert a command signal in response to the sensed power event; and a switch controller coupled to the system controller and configured to receive the command signal, the switch controller further configured to control turn-on and turn-off of the conductance modulation device by changing a rise time, a fall time, or both, of a voltage across the conductance modulation device to control energy delivery to the load in response to a first command in the command signal, wherein the switch controller is configured to not change the rise time, the fall time, or both, in response to a second command in the command signal.

[0092] Example 15. The control system of Example 14, wherein the switch controller further comprises: an adjustable drive element configured to control the rise time, the fall time, or both, of the voltage across the conductance modulation device; an interface coupled to the system controller and configured to receive the command signal, wherein the interface is configured to interpret the command signal and output a drive characteristic signal; and a drive characteristic control device configured to receive the drive characteristic signal and change the adjustable drive element to adjust the rise time, the fall time, or both, of the voltage across the conductance modulation device from a default value in response to the first command in the command signal, the drive characteristic control device configured to not change the rise time, the fall time, or both, from a default value in response to the second command in the command signal.

[0093] Example 16. The control system of Example 14 or 15, wherein the adjustable drive element further comprises: a switch coupled to the drive characteristic control device, wherein the drive characteristic control device is configured to turn the switch on or off to enable or disable conduction of the conductance modulation device; and a tunable current source coupled to the drive characteristic control device and coupled in series with the switch, wherein the drive characteristic control device is configured to control an amplitude of a current provided by the tunable current source controlled by the drive characteristic control device to change the rise time, the fall time, or both, of the voltage across the conductance modulation device in response to the drive characteristic signal.

[0094] Example 17. The control system of any one of Examples 14 to 16, wherein the amplitude of the current provided by the tunable current source is increased in response to the first command.

[0095] Embodiment 18. A switch controller configured to control energy delivery to a load by controlling turn-on and turn-off of a conductivity modulation device, the switch controller comprising: a drive characteristic control device configured to receive a drive characteristic from a command signal, wherein the command signal is provided to actively adjust a drive current of the conductivity modulation device; and a first drive element coupled to the drive characteristic control device, the first drive element comprising: a first switch coupled to the drive characteristic control device and configured to turn on or turn off to transition the conductivity modulation device from a first state to a second state; and a first adjustable current source coupled to the drive characteristic control device and in series with the first switch, the first adjustable current source configured to provide current to the conductivity modulation device to transition the conductivity modulation device from the first state to the second state at a first rate in response to a first command of the command signal, and to provide current to the conductivity modulation device to transition the conductivity modulation device from the first state to the second state at a second rate in response to a second command of the command signal.

[0096] Embodiment 19. The switch controller of Embodiment 18, further comprising: a second drive element coupled to the drive characteristic control device, wherein the second drive element comprises: a second switch coupled to the drive characteristic control device and configured to turn on or turn off to transition the conductivity modulation device from the second state to the first state; and a second adjustable current source coupled to the drive characteristic control device and in series with the second switch, the second adjustable current source configured to provide current to the conductivity modulation device to transition the conductivity modulation device from the second state to the first state at the first rate in response to the first command of the command signal, and to provide current to the conductivity modulation device to transition the conductivity modulation device from the second state to the first state at the second rate in response to the second command of the command signal.

[0097] Embodiment 20. The switch controller of Embodiments 18 or 19, wherein the command signal is received from a system controller.

[0098] Embodiment 21. The switch controller of any one of Embodiments 18 to 20, wherein the command signal is received from a user trigger.

[0099] Embodiment 22. The switch controller of any one of Embodiments 18 to 21, wherein the command signal is received from a sensor.

Claims

1. A control system configured to control a conductivity modulation device of a power switch array, the conductivity modulation device configured to control energy delivery to a load, the control system comprising: a system controller configured to sense a power event in the control system and output a command signal to adjust a magnitude of a current driving the conductivity modulation device in response to the sensed power event; and a switch controller coupled to the system controller and configured to receive the command signal output by the system controller, the switch controller further configured to control energy delivery to the load by controlling turn-on and turn-off of the conductivity modulation device, wherein the switch controller comprises an adjustable drive element configured to control a rise time of a voltage across the conductivity modulation device, a fall time of a voltage across the conductivity modulation device, or both the rise time and the fall time; an interface coupled to the system controller and configured to receive the command signal output by the system controller, wherein the interface is configured to interpret the command signal output by the system controller to output a drive characteristic signal, the drive characteristic signal representing a magnitude of a current driving the conductivity modulation device, and a drive characteristic control device configured to receive the drive characteristic signal and responsively change a magnitude of a current driving the conductivity modulation device, wherein the drive characteristic control device is configured to change the adjustable drive element to adjust the rise time of a voltage across the conductivity modulation device, the fall time of a voltage across the conductivity modulation device, or both in response to a first command in the command signal output by the system controller, and not to change the rise time, the fall time, or both from a default value in response to a second command in the command signal output by the system controller.

2. The control system of claim 1, the drive characteristic control device configured to adjust the rise time of a current conducted by the conductivity modulation device, the fall time of a current conducted by the conductivity modulation device, or both.

3. The control system of claim 1, wherein the adjustable drive element comprises: a switch coupled to the drive characteristic control device, the switch configured to turn on or turn off to enable or disable conduction of a current through the conductivity modulation device; and a tunable current source coupled to the drive characteristic control device and in series with the switch, the drive characteristic control device further configured to control a current provided by the tunable current source to change the rise time and / or fall time of a voltage across the conductivity modulation device in response to the command signal output by the system controller. ​ 4. The control system of claim 3, the drive characteristic control device further configured to control a rise time of current conducted by the conductivity modulation device, a fall time of current conducted by the conductivity modulation device, or both, by the current provided by the adjustable current source.

5. The control system of claim 3, wherein the drive characteristic control device is further configured to control an amplitude of the current provided by the adjustable current source.

6. The control system of claim 3, wherein the drive characteristic control device is further configured to control a duration of the current provided by the adjustable current source.

7. The control system of claim 3, wherein the drive characteristic control device is further configured to control a frequency of the current provided by the adjustable current source.

8. The control system of claim 1, wherein the interface is galvanically isolated from the drive characteristic control device.

9. The control system of claim 1, wherein the control system controls energy delivery to a motor.

10. The control system of claim 1, wherein the conductivity modulation device is a transistor.

11. The control system of claim 1, wherein the command signal output by the system controller is a rectangular pulse waveform having a logic high portion and a logic low portion, wherein a duration of the logic low portion corresponds to a command of the command signal.

12. The control system of claim 1, wherein the system controller is configured to output the command signal to adjust the conductivity modulation device as needed.

13. A control system configured to control a conductivity modulation device configured to control energy delivery to a load, the control system comprising: a system controller configured to sense a power event in the control system and assert a command signal in response to the sensed power event; and a switch controller coupled to the system controller and configured to receive the command signal asserted by the system controller, the switch controller further configured to control an amplitude of a current that turns on and off to drive the conductivity modulation device to control energy delivery to the load by changing a rise time, a fall time, or both, of a voltage on the conductivity modulation device in response to a first command in the command signal asserted by the system controller, wherein the switch controller is configured to not change the rise time, the fall time, or both, in response to a second command in the command signal asserted by the system controller.

14. The control system of claim 13, wherein the switch controller further comprises: an adjustable drive element configured to control the rise time, the fall time, or both, of the voltage on the conductivity modulation device; an interface coupled to the system controller and configured to receive the command signal asserted by the system controller, wherein the interface is configured to interpret the command signal asserted by the system controller and output a drive characteristic signal; and a drive characteristic control device configured to receive the drive characteristic signal and change the adjustable drive element to adjust a rise time, a fall time, or both, of a voltage across the conductivity modulation device from a default value in response to the first command in the command signal asserted by the system controller, the drive characteristic control device configured to not change the rise time, the fall time, or both, from a default value in response to the second command in the command signal asserted by the system controller.

15. The control system of claim 14, wherein the adjustable drive element further comprises: a switch coupled to the drive characteristic control device, wherein the drive characteristic control device is configured to turn the switch on or off to enable or disable conduction of the conductivity modulation device; and a tunable current source coupled to the drive characteristic control device and in series with the switch, wherein the drive characteristic control device is configured to control an amplitude of a current provided by the tunable current source controlled by the drive characteristic control device in response to the drive characteristic signal to change the rise time, the fall time, or both, of a voltage across the conductivity modulation device.

16. The control system of claim 15, wherein the amplitude of the current provided by the tunable current source is increased in response to the first command.

17. A switch controller configured to control energy delivery to a load by controlling turn-on and turn-off of a conductivity modulation device, the switch controller comprising: a drive characteristic control device configured to receive an amplitude of a drive current from a command signal, wherein the command signal is provided to actively adjust the drive current of the conductivity modulation device; and a first drive element coupled to the drive characteristic control device, the first drive element comprising: a first switch coupled to the drive characteristic control device and configured to turn on or off to transition the conductivity modulation device from a first state to a second state; and a first tunable current source coupled to the drive characteristic control device and in series with the first switch, the first tunable current source configured to provide a current for the conductivity modulation device to transition the conductivity modulation device from the first state to the second state at a first rate in response to a first command of the command signal and to provide a current for the conductivity modulation device to transition the conductivity modulation device from the first state to the second state at a second rate in response to a second command of the command signal.

18. The switch controller of claim 17, further comprising: a second drive element coupled to the drive characteristic control, wherein the second drive element comprises: a second switch coupled to the drive characteristic control and configured to turn on or off to transition the conductivity modulation device from the second state to the first state; and a second adjustable current source coupled to the drive characteristic control and in series with the second switch, the second adjustable current source configured to provide current to the conductivity modulation device to transition the conductivity modulation device from the second state to the first state at the first rate in response to the first command of the command signal and to provide current to the conductivity modulation device to transition the conductivity modulation device from the second state to the first state at the second rate in response to the second command of the command signal.

19. The switch controller of claim 17, wherein the command signal is received from a system controller.

20. The switch controller of claim 17, wherein the command signal is received from a user trigger.

21. The switch controller of claim 17, wherein the command signal is received from a sensor.

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