System and method for energizing charge pump

Abstract

Apparatuses and methods for energizing a boost charge pump circuit are disclosed. One method implementation includes providing an input voltage at a boost converter input terminal without operating a phase switch or a series switch of a charge pump circuit; determining that the supply voltage of the first set of voltage regulators is sufficient to operate the phase switch at least in a reduced gate drive mode; after the determination, operating the phase switch without operating the series switch; determining that the supply voltage of one voltage regulator in the second set of voltage regulators is sufficient to operate its corresponding series switch at least in a reduced gate drive mode; and after determining that the supply voltage of one voltage regulator in the second group of voltage regulators is sufficient to operate the corresponding series switch, operating the corresponding series switch.

Description

[0001] Priority claim

[0002] This application claims the benefit of priority to U.S. Provisional Application No. 63 / 483,321, filed February 6, 2023, the entire contents of which are incorporated herein by reference for all purposes. Technical Field

[0003] The present disclosure relates to charge pumps, and more particularly, to apparatus, integrated circuits, and methods for powering a boost charge pump circuit. Background Art

[0004] Many electronic products, particularly mobile computing and / or communication products and components (e.g., laptop computers, ultrabook computers, tablet devices, LCD and LED displays), require multiple voltage levels. For example, a power amplifier for a radio frequency transmitter may require a relatively high voltage (e.g., 12 volts (V) or greater), while logic circuits may require a low voltage level (e.g., 1V to 2V). Some other circuits may require an intermediate voltage level (e.g., 5V to 10V). Various configurations of switched capacitor power conversion circuits, sometimes also referred to as "charge pumps," provide voltage conversion between a high-side voltage and a low-side voltage (i.e., step-up, step-down, or bidirectional) by the controlled transfer of charge between capacitors in the circuit. Summary of the Invention

[0005] Embodiments of the present disclosure may provide methods, apparatus, integrated circuits, and circuit boards for powering a boost charge pump circuit. In one embodiment, a method for powering a charge pump circuit operating as a dc-dc boost converter is disclosed. The charge pump circuit includes: a plurality of series switches, each series switch including a gate terminal, a drain terminal, and a source terminal; a plurality of phase switches, each series switch including a gate terminal, a drain terminal, and a source terminal; a plurality of flying capacitors, each flying capacitor including a series-side terminal coupled to a source terminal or a drain terminal of one of the series switches and a phase-side terminal coupled to a source terminal or a drain terminal of one of the phase switches; and a plurality of low-dropout (LDO) voltage regulators associated with each of the series switches and the phase switches, the LDO voltage regulators being configured to provide a supply voltage to a level shifter circuit and a driver circuit associated with each of the series switches and the phase switches; wherein the supply voltage of each of the LDO voltage regulators is based on a voltage at the series-side terminal of one of the flying capacitors or based on an output voltage of the charge pump circuit.

[0006] The method includes: supplying an input voltage to a charge pump circuit from a power supply; providing a turn-off signal to a gate terminal of a series switch and a gate terminal of a phase switch; precharging a flying capacitor via a body diode associated with the series switch; after precharging the flying capacitor, providing a switching signal to a gate terminal of the phase switch to operate the phase switch in a reduced gate drive mode while providing a turn-off signal to a gate terminal of the series switch; determining whether a supply voltage of one of the low-dropout regulators exceeds a predetermined threshold voltage; and after the supply voltage of one of the low-dropout regulators exceeds the predetermined threshold voltage, providing a switching signal to a gate terminal of a series switch associated with one of the low-dropout regulators to operate the series switch in the reduced gate drive mode.

[0007] In one embodiment, a method for powering a charge pump circuit is disclosed, the charge pump circuit being operable as a boost converter and comprising: a plurality of phase switches and series switches, each of the switches including a gate terminal coupled to a gate driver circuit; a plurality of flying capacitors, each flying capacitor coupled between at least one phase switch and the series switch; a first set of voltage regulators, each voltage regulator configured to drive one of the gate driver circuits coupled to one of the phase switches, and each voltage regulator configured to draw a supply voltage from a series-side terminal of at least one of the flying capacitors or a boost converter input terminal; and a second set of voltage regulators, each voltage regulator configured to drive one of the gate driver circuits coupled to one of the series switches. The invention relates to a boost converter comprising: first and second voltage regulators, each configured to draw a supply voltage from a series-side terminal of at least one of the flying capacitors or a boost converter output terminal, the method comprising: providing an input voltage at a boost converter input terminal without operating a phase switch or a series switch; determining that a supply voltage of a first group of voltage regulators is sufficient to operate the phase switch at least in a reduced gate drive mode; operating the phase switch without operating the series switch after determining that the supply voltage of the first group of voltage regulators is sufficient to operate the phase switch; determining that a supply voltage of one of the second group of voltage regulators is sufficient to operate its corresponding series switch at least in a reduced gate drive mode; and operating the corresponding series switch after determining that the supply voltage of one of the second group of voltage regulators is sufficient to operate the corresponding series switch.

[0008] In another embodiment, an integrated circuit is disclosed that includes: a charge pump circuit capable of operating as a boost converter, and the charge pump circuit includes: a plurality of phase switches and series switches, each of the switches including a gate terminal coupled to a gate driver circuit, wherein the phase switches and the series switches are configured to be coupled to a plurality of flying capacitors, each flying capacitor configured to be coupled between at least one phase switch and the series switch; a first set of voltage regulators, each voltage regulator configured to drive one of the gate driver circuits coupled to one of the phase switches, and each voltage regulator configured to draw a supply voltage from a series-side terminal of at least one of the flying capacitors or a boost converter input terminal; and a second set of voltage regulators, each voltage regulator configured to drive one of the gate driver circuits coupled to one of the series switches. one of the plurality of voltage regulators, and each voltage regulator is configured to draw a supply voltage from a series-side terminal of at least one of the flying capacitors or a boost converter output terminal; wherein the charge pump circuit is configured to: receive an input voltage at a boost converter input terminal without operating a phase switch or a series switch; determine that the supply voltage of the first group of voltage regulators is sufficient to operate the phase switch at least in a reduced gate drive mode; operate the phase switch without operating the series switch after determining that the supply voltage of the first group of voltage regulators is sufficient to operate the phase switch; determine that the supply voltage of one of the voltage regulators in the second group of voltage regulators is sufficient to operate its corresponding series switch at least in a reduced gate drive mode; and operate the corresponding series switch after determining that the supply voltage of one of the voltage regulators in the second group of voltage regulators is sufficient to operate the corresponding series switch.

[0009] In yet another embodiment, a power converter apparatus is disclosed, comprising: a charge pump circuit capable of operating as a boost converter, the charge pump circuit comprising: a plurality of phase switches and series switches, each of the switches including a gate terminal coupled to a gate driver circuit; a plurality of flying capacitors, each flying capacitor coupled between at least one of the phase switches and the series switches; a first set of voltage regulators, each of the first set of voltage regulators being configured to drive one of the gate driver circuits coupled to one of the phase switches, and each of the first set of voltage regulators being configured to draw a supply voltage from a series-side terminal of at least one of the flying capacitors or a boost converter input terminal; and a second set of voltage regulators, each of the second set of voltage regulators being configured to drive one of the gate driver circuits coupled to one of the series switches. one, and each voltage regulator in the second group of voltage regulators is configured to draw a supply voltage from a series-side terminal of at least one of the flying capacitors or a boost converter output terminal; wherein the charge pump circuit is configured to: receive an input voltage at the boost converter input terminal without operating the phase switch or the series switch; determine that the supply voltage of the first group of voltage regulators is sufficient to operate the phase switch at least in a reduced gate drive mode; operate the phase switch without operating the series switch after determining that the supply voltage of the first group of voltage regulators is sufficient to operate the phase switch; determine that the supply voltage of one of the voltage regulators in the second group of voltage regulators is sufficient to operate its corresponding series switch at least in a reduced gate drive mode; and operate the corresponding series switch after determining that the supply voltage of one of the voltage regulators in the second group of voltage regulators is sufficient to operate the corresponding series switch.

[0010] In yet another embodiment, a method for powering a charge pump circuit is disclosed, the charge pump circuit being capable of operating as a boost converter and comprising: a plurality of phase switches and series switches, each of the switches including a gate terminal coupled to a gate driver circuit; a plurality of flying capacitors, each flying capacitor coupled between at least one phase switch and the series switch; a first set of voltage regulators, each of the first set of voltage regulators being configured to drive one of the gate driver circuits coupled to one of the phase switches, and each of the first set of voltage regulators being configured to draw a supply voltage from a series side terminal of at least one of the flying capacitors or a boost converter input terminal; and a second set of voltage regulators, each of the second set of voltage regulators being configured to drive one of the gate driver circuits coupled to one of the series switches, and each of the second set of voltage regulators being configured to drive a supply voltage from a series side terminal of at least one of the flying capacitors or a boost converter input terminal. The method is configured to draw a supply voltage from a series-side terminal of at least one of the flying capacitors or a boost converter output terminal, the method comprising: providing an input voltage at a boost converter input terminal without operating a phase switch or a series switch; determining that a supply voltage of a first set of voltage regulators is sufficient to operate the phase switch at least in a reduced gate drive mode; operating the phase switch without operating the series switch after determining that the supply voltage of the first set of voltage regulators is sufficient to operate the phase switch; determining that a voltage at the boost converter output terminal exceeds a threshold voltage; not operating the phase switch and the series switch for a predetermined time period after determining that the voltage at the boost converter output terminal exceeds the threshold voltage; and after the predetermined time period, determining that a supply voltage of a second set of voltage regulators is sufficient to operate the series switch at least in the reduced gate drive mode, and operating both the phase switch and the series switch after determining that the supply voltage of the second set of voltage regulators is sufficient to operate the series switch.

[0011] In yet another embodiment, an integrated circuit is disclosed that includes: a charge pump circuit capable of operating as a boost converter, the charge pump circuit including: a plurality of phase switches and series switches, each of the switches including a gate terminal coupled to a gate driver circuit, wherein the phase switches and the series switches are configured to be coupled to a plurality of flying capacitors, each flying capacitor configured to be coupled between at least one phase switch and the series switch; a first set of voltage regulators, each of the first set of voltage regulators being configured to drive one of the gate driver circuits coupled to one of the phase switches, and each of the first set of voltage regulators being configured to draw a supply voltage from a series-side terminal of at least one of the flying capacitors or a boost converter input terminal; and a second set of voltage regulators, each of the second set of voltage regulators being configured to drive one of the gate driver circuits coupled to one of the series switches, and each of the second set of voltage regulators being configured to drive a supply voltage from a series-side terminal of at least one of the flying capacitors or a boost converter input terminal. The regulator is configured to draw a supply voltage from a series-side terminal of at least one of the flying capacitors or a boost converter output terminal; wherein the charge pump circuit is configured to: receive an input voltage at the boost converter input terminal without operating the phase switch or the series switch; determine that the supply voltage of the first group of voltage regulators is sufficient to operate the phase switch at least in a reduced gate drive mode; after determining that the supply voltage of the first group of voltage regulators is sufficient to operate the phase switch, operate the phase switch without operating the series switch; determine that the voltage at the boost converter output terminal exceeds a threshold voltage; after determining that the voltage at the boost converter output terminal exceeds the threshold voltage, do not operate the phase switch and the series switch for a predetermined time period; and after the predetermined time period, determine that the supply voltage of the second group of voltage regulators is sufficient to operate the series switch at least in a reduced gate drive mode, and after determining that the supply voltage of the second group of voltage regulators is sufficient to operate the series switch, operate both the phase switch and the series switch.

[0012] In another embodiment, a power converter device is disclosed, comprising: a charge pump circuit capable of operating as a boost converter, and the charge pump circuit comprising: a plurality of phase switches and series switches, each of the switches including a gate terminal coupled to a gate driver circuit; a plurality of flying capacitors, each flying capacitor coupled between at least one phase switch and the series switch; a first set of voltage regulators, each of the first set of voltage regulators being configured to drive one of the gate driver circuits coupled to one of the phase switches, and each of the first set of voltage regulators being configured to draw a supply voltage from a series-side terminal of at least one of the flying capacitors or a boost converter input terminal; and a second set of voltage regulators, each of the second set of voltage regulators being configured to drive one of the gate driver circuits coupled to one of the series switches, and each of the second set of voltage regulators being configured to draw a supply voltage from A series side terminal of at least one of the flying capacitors or a boost converter output terminal draws a supply voltage; wherein the charge pump circuit is configured to: receive an input voltage at the boost converter input terminal without operating the phase switch or the series switch; determine that the supply voltage of the first group of voltage regulators is sufficient to operate the phase switch at least in a reduced gate drive mode; after determining that the supply voltage of the first group of voltage regulators is sufficient to operate the phase switch, operate the phase switch without operating the series switch; determine that the voltage at the boost converter output terminal exceeds a threshold voltage; after determining that the voltage at the boost converter output terminal exceeds the threshold voltage, do not operate the phase switch and the series switch for a predetermined time period; and after the predetermined time period, determine that the supply voltage of the second group of voltage regulators is sufficient to operate the series switch at least in a reduced gate drive mode, and after determining that the supply voltage of the second group of voltage regulators is sufficient to operate the series switch, operate both the phase switch and the series switch.

[0013] It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the invention, as claimed. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1A is a block diagram of an exemplary charge pump circuit 100 according to the disclosed embodiments.

[0015] Figure 1B is a circuit diagram of an exemplary charge pump circuit 100 according to the disclosed embodiments.

[0016] Figure 1C and Figure 1D is a circuit diagram illustrating further exemplary aspects of the charge pump circuit 100 according to the disclosed embodiments.

[0017] Figure 2is a block diagram illustrating an exemplary power-up process 200 for the charge pump circuit 100 operating as a boost converter.

[0018] Figure 3 is a circuit timing diagram 300 illustrating aspects of an exemplary power-up process for the charge pump circuit 100 operating as a boost converter.

[0019] Figure 4 is a circuit diagram illustrating an exemplary comparator circuit 400 according to disclosed embodiments.

[0020] Figure 5 is a block diagram illustrating an exemplary alternative power-up process for the charge pump circuit 100 operating as a boost converter.

[0021] Figure 6 is a circuit timing diagram illustrating aspects of an exemplary power-up process for the charge pump circuit 100 operating as a boost converter.

[0022] Figure 7 is a circuit diagram illustrating exemplary aspects of operating the charge pump circuit 100 in a reduced gate drive mode in accordance with disclosed embodiments.

[0023] Figure 8A and Figure 8B is a circuit timing diagram illustrating aspects of an exemplary power-up process for the charge pump circuit 100 operating as a boost converter.

[0024] Figure 9 is a circuit diagram illustrating exemplary aspects of operating the charge pump circuit 100 in a reduced gate drive mode in accordance with disclosed embodiments.

[0025] Figure 10 is the circuit diagram, and Figure 11 is a related circuit timing diagram illustrating exemplary advantages of the disclosed power-up process for the charge pump circuit 100 . DETAILED DESCRIPTION

[0026] The following disclosure provides many different exemplary embodiments or examples for implementing the different features of the provided subject matter. Specific simplified examples of components and arrangements are described below to illustrate the present disclosure. Of course, these are merely examples and are not intended to be limiting. In addition, for clarity, certain features may be omitted from some of the drawings and descriptions, and it should be understood that different features from different drawings and / or parts of the specification may be combined in a single embodiment, and the present disclosure contemplates all such embodiments that combine different features from different drawings and / or parts of the specification. In addition, the present disclosure may repeat figure numerals and / or letters in various examples. This repetition is for simplicity and clarity purposes and does not, in itself, dictate the relationship between the various embodiments and / or configurations discussed.

[0027] In power conversion, system designers are faced with different scenarios for starting a bidirectional power converter. In one embodiment, the bidirectional power converter can detect which source is connected for its startup. For example, when the input is the source, the bidirectional power converter can be started by using the input, and when the output is the source, the bidirectional power converter can be started from the output. This may require two different startup schemes, which increases the complexity of the design and / or increases the total cost associated with the design. In some embodiments, starting from a battery as a source may be beneficial for the bidirectional power converter to reduce its design complexity. However, if the battery does not have sufficient margin, it may not be possible to start from the battery. In this case, it may be beneficial to connect a parallel charger such as a low dropout regulator (LDO) to the battery, which can charge the battery to a sufficient margin (i.e., 3.0V).

[0028] A power converter such as a charge pump can be used as part of an efficient battery charging system with USB Programmable Power Supply (PPS) capability. The input to the voltage converter can be transmitted from a USB PPS adapter to a mobile device via the VBUS pin. However, if the USB PPS adapter is not connected to the mobile device, the charge pump may lack a source input. In such an embodiment, starting from the battery can be beneficial. The following embodiments describe a startup scheme for a bidirectional power converter, including situations where the battery has sufficient headroom to start the power converter and can act as a source.

[0029] Figure 1A FIG. 1 is a block diagram of an exemplary charge pump circuit 100 according to the disclosed embodiment. The charge pump circuit 100 can provide a high-side voltage V by controlling the transfer of charge between capacitors in the circuit. IN With the low-side voltage V OUTThe operation of the charge pump 102 may be controlled by a controller 106. The controller 106 may provide control signals, such as p1 (and / or its complement) and p2 (and / or its complement), to control the charge transfer in the charge pump 102.

[0030] Figure 1B FIG. 1 is a circuit diagram of an exemplary charge pump circuit 100 according to the disclosed embodiment. Figure 1B As shown, the charge pump circuit 100 may include series switches M1, M2, M3, and M4, and M1 OP 、M2 OP 、M3 OP and M4 OP The term "op" may be referred to as "op-phase". The charge pump circuit 100 may further include high-side phase switches M5 and M7, and low-side phase switches M6 and M8. Although the switches M1 to M4, M1 OP To M4 OP and M5 to M8 are depicted as N-channel enhancement mode MOSFETs, but it will be appreciated that any other type of MOSFET may be used, and indeed any other type of known switching device may be used. The switched capacitor circuit may also include a flying capacitor C A 、C B and C C and C A_OP 、C B_OP and C C_OP .like Figure 1B As shown, the flying capacitor C A 、C B and C C The voltages at the series terminals can be V CA 、V CB and V CC Similarly, the flying capacitor C A_OP 、C B_OP and C C_OP The voltages at the series terminals can be V CA_OP 、V CB_OP and V CC_OP . Flying capacitor C A 、C C 、C A_OP and C C_OP The voltage of the phase side terminal can be V PC / PA , and the flying capacitor C B and C B_OP The voltage of the phase side terminal can be V PB Controller 106 ( Figure 1B(not shown) can provide control signals, such as p1 (and / or its complementary signal) and p2 (and / or its complementary signal) to control the switching devices M1 to M8 and thereby control the capacitor C A 、C B and C C and C A_OP 、C B_OP and C C_OP When operated as a buck converter, the switched capacitor circuit can transfer the charge between the input voltage V INT Step down to voltage V X , voltage V X The output voltage V of the charge pump can be obtained by using the inductor L1 and the capacitor C1. OUT To provide.

[0031] Figure 1C and Figure 1D is a circuit diagram illustrating further exemplary aspects of the charge pump circuit 100 according to the disclosed embodiment. Figure 1C In some embodiments, the level shifter circuit 103 and the gate driver circuit 105 can be used to drive the gate terminals of the switches M (eg, switches M1 to M8) in the charge pump circuit 100. Figure 1C As shown, in some embodiments, separate low dropout voltage regulators (LDOs) 107 and 109 can be used to drive the gate driver circuit 105 and the level shifter circuit 103 for the switching device M, and separate supply voltages V Supply1 and V Supply2 The charge pump circuit 100 is used to power the low dropout voltage regulator (LDO) 107 and the low dropout voltage regulator (LDO) 109. The reason for using separate LDOs with separate supply voltages for the level shifter circuit 103 and the gate driver circuit 105 is that if the level shifter circuit 103 and the gate driver circuit 105 share an LDO with a single supply voltage, then in this case the level shifter circuit is usually sensitive to supply voltage fluctuations due to transients in the gate voltage. In general, the external input voltage to the charge pump circuit 100 can be selected, such as V INT (from external power supply) or V BAT (from an external battery) as the supply voltage for the LDO that powers the sensitive level shifter circuit 103, while a fluctuating intermediate voltage such as V CA 、V CB 、V CC 、V CA_OP 、V CB_OP 、V CC_OP or V X As the supply voltage of the LDO that supplies power to the gate driver circuit 105.

[0032] In the case of using an N-channel MOSFET as the switching device M, for similar switching devices, it is generally required that the gate voltage is greater than the source voltage to activate the switching device. In addition, the supply voltage V of LDO 107 and LDO 109 is generally required to be greater than the source voltage. Supply1 and V Supply2 Exceed the required gate voltage by at least the minimum margin (dropout voltage) required for LDO 107 and LDO 109. Therefore, the supply voltage V Supply1 and V Supply2 It is usually necessary to exceed the source voltage at the switching device M, for example, at least the Vgs of the device M plus the voltage drop of LDO 107 and LDO 109. Figure 1D As shown, the supply voltages for the different LDOs in the charge pump circuit 100 that meet these requirements can be drawn from different parts of the charge pump circuit 100 itself. For example, in some embodiments, when the charge pump circuit 100 is operated as a buck converter, the supply voltage V for each of the level shifter circuit and the gate driver circuit can be Supply1 and V Supply2 Can be configured as Figure 1D are shown in and listed in the table below. Figure 1D And in Table 1, V CBOOT May refer to the use of bootstrap capacitors / circuits ( Figure 1D not shown) bootstrapped to V INT Voltages above this, such as V INT +5V.

[0033]

[0034] Table 1 Input supply of level shifter and driver

[0035] Reference Figure 1B , when attempting to operate the charge pump circuit 100 as a boost converter, Figure 1B V OUT The terminal can now be used as an input terminal instead and can be connected to a battery, with a voltage of V BAT supply, and Figure 1B V INT The terminal can now be used as an output terminal instead to provide a boosted output voltage. However, the inventors have realized that in this scenario, the supply voltage and related electrical connections described above may not always meet the gate voltage and LDO voltage drop margin requirements, especially when the charge pump circuit 100 first starts operating the switching devices M1 to M8 (including M1, M2, M3 and M4, M1 OP 、M2 OP 、M3 OP、M4 OP , M5, M6, M7 and M8) to establish the storage in the flying capacitor C A 、C AOP 、C B 、C BOP 、C C and C COP This may be partly due to the fact that the input voltage terminal V BAT With terminal voltage V CA / V CA_OP 、V CB / V CB_OP 、V CC / V CC_OP MOSFET switching devices M1 to M4 and M1 between OP To M4 OP The voltage drop of the body diode and the supply voltage of the LDO from which it is drawn or bootstrapped is V OUT (See Figure 1D ).

[0036] Embodiments of the present disclosure provide methods for powering up a charge pump circuit 100 operating as a boost converter in a manner that meets the gate voltage and LDO voltage drop headroom requirements described above. Figure 2 is a block diagram illustrating an exemplary power-up process 200 for the charge pump circuit 100 operating as a boost converter. Figure 3 is a circuit timing diagram 300 illustrating aspects of an exemplary power-up process for the charge pump circuit 100 operating as a boost converter. Figure 1B 、 Figure 2 and Figure 3 In some embodiments, initially, switches M1, M2, M3, and M4 are connected in series with M1. OP 、M2 OP 、M3 OP and M4 OP And the phase switches M5 to M8 are turned off and do not operate because the LDOs that power their respective level shifter circuits and gate driver circuits do not necessarily meet the gate voltage and LDO voltage drop margin requirements described above. Figure 2 At step 210, V BAT The input voltage supply is provided at the terminal (e.g., from a battery source), thereby switching the series connected switches M1 to M4 and M1 OP To M4 OP The body diode to V INT Terminals and flying capacitor C A 、C A_OP 、C B 、C B_OP 、C C and CC_OP Precharge. Figure 3 As shown, during this pre-charge phase 320, example traces 303, 305, and 307 illustrate the series connection of switches M1 to M4 and M1. OP To M4 OP can be turned off and not operated, and example traces 308, 309, and 310 show that phase switches M5 to M8 can also be turned off and not operated. As shown in example trace 301, V INT Initially can be precharged to V BAT –4*V Diode , where V Diode is the voltage drop across the body diode of one of the series switches. Similarly, traces 302, 304, and 306 show that the voltage at the series side terminals of the flying capacitor can initially be precharged to V BAT –k*V Diode , where k is set at the input terminal V BAT The charge pump circuit 100 may be configured to operate in phase 320 for a predetermined period of time.

[0037] Phase switches M5 to M8 can be placed in (a) normal power converter operation with low R ON in the overdriven on-state, or (2) with a higher R ON The higher R is selected for reduced drive conduction states, such as during dynamic reconfiguration of the conversion ratio of the power converter, during power converter startup, when balancing the charge in flying capacitors within the power converter, or during fault events such as short circuit events. ON This provides protection against potentially destructive events such as inrush or charge transfer currents.

[0038] exist Figure 2 At step 220, the switching of phase switches M5 to M8 can be started in the reduced gate drive mode because V is fully established during the pre-charge phase. CA 、V CA_OP and V Xvoltage to meet the gate voltage and LDO voltage drop headroom requirements for operating phase switches M5 to M8 in the reduced gate drive mode. For example, the startup and / or operation of any switch in any of the embodiments discussed herein can be performed according to the methods and systems described in U.S. Patent Application Publication No. 2022 / 0385178A1 (published on December 1, 2022), the entire contents of which are incorporated herein by reference for all purposes. In the reduced gate drive mode, phase switches M5 to M8 can be operated in their respective current saturation regions, where the voltage Vgs across their respective gate-source junctions is reduced (e.g., M5 to M8 are N-channel MOSFETs).

[0039] In an alternative embodiment, V BAT or V BAT With V INT 、V CA 、V CA OP 、V CB 、V CB_OP 、V CC or V CC_OP Any combination of (e.g., OR function) enables switching of phase switches M5 to M8 in a reduced gate drive mode to achieve gate voltage and LDO voltage drop margin requirements. In such an embodiment, it is possible to provide Figure 7 A separate gate driver circuit 710 is shown with reduced gate driver capability to use V BAT (alone or with V INT 、V CA 、V CA_OP 、V CB 、V CB_OP 、V CC or V CC_OP The phase switches M5 to M8 are operated in a reduced gate drive mode. Figures 8A to 8B As shown, although the example gate-source voltage V GS Trace 810 and example gate-source voltages V for low-side phase switches M6 and M8 GS Trace 820 is reduced (eg, <2V swing), but switching operation of switches M5 through M8 is achieved, as shown by example trace 830 .

[0040] In yet another alternative embodiment, when N-channel MOSFETs are used for the phase switches M5 to M8, each phase switch M5 to M8 may be additionally provided with a parallel electrically coupled P-channel MOSFET operating as a weak switch, such as Figure 9This P-channel MOSFET 910 may not require a bootstrap voltage and can use V BAT The input voltage directly activates its switch. The use of P-channel MOSFET 910 may cause the N-channel MOSFET based phase switches M5 to M8 to be bypassed to transfer charge from V BAT The input terminal is transferred to the flying capacitor. It should be understood that, for example, at V BAT When the input voltage is relatively low, you can use Figure 7 and Figure 9 implementation method.

[0041] Series switches M1 to M4 and M1 OP To M4 OP The phase switch can continue to be turned off and not operated in the switching state. Figure 3 As shown, during the switching state 330 of the phase switch, example traces 308, 309 and 310 show that the phase switches M5 to M8 can be activated and they can operate in a reduced gate drive mode. Example traces 303, 305 and 307 show the series connection of the switches M1 to M4 and M1 OP To M4 OP At this point in time it is still possible to turn off and not operate. As shown by example traces 301, 302, 304 and 306, during this phase 330, as the phase switches M5 to M8 transfer charge from the input voltage terminal V BAT Transfer to flying capacitor C A 、C A_OP 、C B 、C B_OP 、C C and C C_OP operation, the output voltage V INT The voltage at the series side terminals of the flying capacitor can continue to build.

[0042] exist Figure 2 At step 230, it can be checked that V INT 、V CC_OP 、V CC 、V CB_OP 、V CB 、V CA_OP and V CA Voltage (for operating the series switches M1 to M4 and M1 OP To M4 OP The supply voltage of the LDO is drawn from these voltages or bootstrapped) to determine whether any of these voltages has been sufficiently established during the switching state of the phase switch to meet the requirements for starting the series switches M1 to M4 and M1 OP To M4 OPThe gate voltage and LDO voltage drop margin requirements of the switch are reduced and operated in gate drive mode. Figure 4 As shown, the charge pump circuit 100 may include a comparator circuit 400 to convert, for example, V INT 、V CC_OP 、V CC 、V CB_OP 、V CB 、V CA_OP and V CA The voltage and threshold voltage V LDO O / P Compare to determine whether their corresponding series switches M1 to M4 or M1 can be activated OP To M4 OP (See Table 1 above) and operate in reduced gate drive mode. If V is fully established during the switching state of the phase switch INT 、V CC_OP 、V CC 、V CB_OP 、V CB 、V CA_OP or V CA voltages to satisfy the requirement for operating the corresponding series switches M1 to M4 or M1 in the reduced gate drive mode. OP To M4 OP The gate voltage and LDO voltage drop margin requirements are Figure 2 At step 240, the corresponding series switches M1 to M4 or M1 OP To M4 OP The switches can be started and operated in a reduced gate drive mode. This process can be repeated until all series switches M1 to M4 and M1 OP To M4 OP The switches are already enabled and operating in a reduced gate drive mode. In some embodiments, using a comparator circuit such as comparator circuit 400 in this manner can be performed in series with switches M1 to M4 or M1. OP To M4 OP Multiple checkpoints are allowed before the switch is enabled and operated (eg, in a reduced gate drive mode).

[0043] like Figure 3 As shown, during the switching state 330 of the phase switch, example traces 301, 302, 304 and 306 show the output voltage V INT The voltage at the series side terminal of the flying capacitor may have increased sufficiently so that its corresponding series switches M1 to M4 or M1OP to M4OP (see Table 1 above) can start switching and operate in a reduced gate drive mode. Example traces 303, 305 and 307 show the series switches M1 to M4 and / or M1OP.OP To M4 OP As shown by example traces 301, 302, 304 and 306, during this phase 330, the phase switches M5 to M8 and the series switches M1 to M4 and / or M1 are turned on. OP To M4 OP The charge is transferred from the input voltage terminal V BAT Transfer to flying capacitor C A 、C A_OP 、C B 、C B_OP 、C C and C C_OP operation, the output voltage V INT The voltage at the series side terminals of the flying capacitor can continue to build.

[0044] As mentioned above, this process can be repeated until all series switches M1 to M4 and M1 OP To M4 OP The switch has been enabled and is operating in a reduced gate drive mode. Figure 3 As shown, during the stable operation phase 304, example traces 308, 309, and 310 show that all phase switches M5 to M8 have started switching and are operating in a reduced gate drive mode. Similarly, example traces 303, 305, and 307 show that all series switches M1 to M4 and M1 OP To M4 OP The switches are already enabled and are operating in reduced gate drive mode. Subsequently, all series switches M1 to M4 and M1 OP To M4 OP And the phase switches M5 to M8 can be switched from operating in the reduced gate drive mode to operating in the full gate drive mode.

[0045] Figure 5 is a block diagram illustrating an exemplary alternative power-up process for the charge pump circuit 100 operating as a boost converter. Figure 6 is a circuit timing diagram illustrating aspects of an exemplary alternative power-up process for the charge pump circuit 100 operating as a boost converter. Figure 1B 、 Figure 5 and Figure 6 In some embodiments, initially, switches M1, M2, M3, and M4 are connected in series with M1. OP 、M2 OP 、M3 OP and M4 OPAnd the phase switches M5 to M8 are turned off and do not operate because the LDOs that power their respective level shifter circuits and gate driver circuits do not necessarily meet the gate voltage and LDO voltage drop margin requirements described above. Figure 5 At step 510, V BAT The input voltage supply is provided at the terminals (e.g., from an external battery source), thereby switching the series connected switches M1 to M4 and M1 OP To M4 OP The body diode to V INT Terminals and flying capacitor C A 、C A_OP 、C B 、C B_OP 、C C and C C_OP Precharge. Figure 6 As shown, during this precharge phase 620, example trace 601 shows that V BAT Example traces 607, 608, 609, and 610 show the series connection of switches M1 to M4 and M1 OP To M4 OP can be turned off and not operated, and example traces 603, 604, 605, and 606 show that phase switches M5 to M8 can also be turned off and not operated. As shown in example trace 602, V INT Initially can be precharged to V BAT –4*V Diode , where V Diode is the voltage drop across the body diode of one of the series switches.The charge pump circuit 100 may be configured to operate in stage 620 for a predetermined period of time.

[0046] exist Figure 5 At step 520, phase switches M5 to M8 may start switching and operate in a reduced gate drive mode because V is already sufficiently established during the pre-charge phase. CA 、V CA_OP and V X The voltage is reduced to meet the gate voltage and LDO voltage drop margin requirements for operating the phase switches M5 to M8 in the reduced gate drive mode. In the reduced gate drive mode, the phase switches M5 to M8 can operate in their respective current saturation regions, where the voltage Vgs across their respective gate-source junctions is reduced (e.g., M5 to M8 are N-channel MOSFETs).

[0047] In an alternative embodiment, V BAT or V BAT With V INT 、V CA 、V CA_OP、V CB 、V CB_OP 、V CC or V CC_OP Any combination of (e.g., OR function) enables switching of phase switches M5 to M8 in a reduced gate drive mode to achieve gate voltage and LDO voltage drop margin requirements. In such an embodiment, it is possible to provide Figure 7 The separate reduced gate driver circuit 710 is shown to use V BAT (alone or with V INT 、V CA 、V CA_OP 、V CB 、V CB_OP 、V CC or V CC_OP The phase switches M5 to M8 are operated in a reduced gate drive mode. Figures 8A to 8B As shown, although the example gate-source voltage V GS Trace 810 and example gate-source voltages V for low-side phase switches M6 and M8 GS Trace 820 is reduced (eg, <2V swing), but switching operation of switches M5 through M8 is achieved, as shown by example trace 830 .

[0048] In yet another alternative embodiment, when N-channel MOSFETs are used for the phase switches M5 to M8, each phase switch M5 to M8 may be additionally provided with a parallel electrically coupled P-channel MOSFET operating as a weak switch, such as Figure 9 This P-channel MOSFET 910 does not require a bootstrap voltage and can use V BAT The input voltage directly activates its switch, and it uses V BAT The use of P-channel MOSFET 910 can cause the N-channel MOSFET based phase switches M5 to M8 to be bypassed to transfer charge from V BAT The input terminals are transferred to flying capacitors.

[0049] Series switches M1 to M4 and M1 OP To M4 OP The phase switch can continue to be turned off and not operated in the switching state. Figure 6 As shown, during the switching state 630 of the phase switch, example traces 603, 604, 605 and 606 show that phase switches M5 to M8 can start switching and operate in a reduced gate drive mode. Example traces 607, 608, 609 and 610 show that series switches M1 to M4 and M1 OP To M4 OPAt this point in time it can still be turned off and not operating. As shown in example trace 602, during this phase 630, as phase switches M5 to M8 transfer charge from the input voltage terminal V BAT Transfer to flying capacitor C A 、C A_OP 、C B 、C B_OP 、C C and C C_OP operation, the output voltage V INT (and the voltage at the series side terminals of the flying capacitor) can continue to build.

[0050] exist Figure 5 At step 530, the boost output voltage V INT to determine whether it has been established during the phase switch conduction phase to exceed the threshold requirement, for example, to meet the requirements of operating the series switches M1 to M4 and M1 in the reduced gate drive mode. OP To M4 OP A certain gate voltage and LDO voltage drop margin requirement. For example, Figure 4 As shown, the charge pump circuit 100 may include a comparator circuit 400 to convert V INT voltage and threshold voltage V LDO O / P Compare to determine V INT Has it been adequately established to exceed the threshold requirements? If so, Figure 5 At step 540, phase switches M5 to M8 may be turned off and not operated for a predetermined period of time, and the LDO may be turned on and allowed to stabilize. During the predetermined period of time, the series switches M1 to M4 and M1 OP To M4 OP It can also remain switched off and not operate. For example, a predetermined time period can be provided so that V INT Stabilizes and allows the supply voltage to the LDO and the output voltage from the LDO to stabilize. Figure 6 As shown, during this stable phase 640, example traces 603, 604, 605, and 606 show that phase switches M5 to M8 may be turned off and not operated. Example traces 607, 608, 609, and 610 show that series switches M1 to M4 and M1 OP To M4 OP As shown in example trace 602, during this phase 640, as charge is removed from the flying capacitor C A 、C A_OP 、C B 、C B_OP 、C C and C C_OP Transfer to VINT Terminal, output voltage V INT Stablize.

[0051] After a predetermined period of time, Figure 5 At step 550, after V has been fully established in the previous stage INT 、V CC_OP 、V CC 、V CB_OP 、V CB 、V CA_OP and V CA After the voltage meets the gate voltage and LDO voltage drop margin requirements, all series switches M1 to M4 and M1 OP To M4 OP And the phase switches M5 to M8 can start switching and operate in a reduced gate drive mode. Figure 6 As shown, during the stable operation phase 605, example traces 603, 604, 605, and 606 show that all phase switches M5 to M8 have started switching and are operating in a reduced gate drive mode. Similarly, example traces 607, 608, 609, and 610 show that all series switches M1 to M4 and M1 OP To M4 OP The switches have been enabled and are operating in reduced gate drive mode. Subsequently, all series switches M1 to M4 and M1 OP To M4 OP And the phase switches M5 to M8 can be switched from operating in the reduced gate drive mode to operating in the full gate drive mode.

[0052] Figure 10 is the circuit diagram, and Figure 11 is a related circuit timing diagram illustrating exemplary advantages of the disclosed power-up process for the charge pump circuit 100. Figure 10 As shown, in system 1000, an integrated circuit charge pump circuit 1010 can be coupled to a plurality of external flying capacitors, for example, C1, C2, C3, C4, C5, and C6. The charge pump circuit 1010 can be capable of operating as a buck converter, for example, to reduce the voltage at terminal Vin to voltage VOUT. The charge pump circuit 1010 can also be capable of operating as a boost converter, for example, to increase the voltage at terminal VOUT to voltage Vin.

[0053] Additionally, the charge pump circuit 1010 may be coupled to an internal power source such as a battery of a mobile phone (eg, C OUT1020) and an external power source (e.g., Vusb 1040). The system 1000 may include a disconnect switch 1050 configured to connect the external power source Vusb 1040 to the charge pump circuit 1010 or disconnect the external power source Vusb 1040 from the charge pump circuit 1010. In some scenarios, connecting the external power source Vusb 1040 to the charge pump circuit 1010 by turning on the disconnect switch 1050 may result in an undesirable inrush current (e.g., capable of damaging components of the system 1000 or the charge pump circuit 1010, or triggering a fault that prevents the system 1000 or the charge pump circuit 1010 from operating normally).

[0054] Therefore, in some embodiments, before turning on the disconnect switch 1050 and connecting the external power supply Vusb 1040 to the charge pump circuit 1010, it may be advantageous to increase the voltage at the terminal Vin so that it is close to or equal to Vusb 1040, so that when the disconnect switch 1050 is turned on and the external power supply Vusb 1040 is connected to the charge pump circuit 1010, the inrush current is minimized or eliminated. Doing so may also eliminate the need for an internal boost supply during power-up of the charge pump circuit 1010. Furthermore, during the time that the disconnect switch 1050 is turned on, the flying capacitors can be charged to one or more appropriate ratios of the input voltage while the phases and / or series switches of the charge pump circuit are operating in a reduced gate drive mode, as described above.

[0055] To achieve this, Figure 11 As shown, the charge pump circuit 1010 can initially advantageously operate as a boost converter, for example, boosting the voltage VOUT at the terminal (e.g., supplied by a battery) to the voltage Vin, thereby raising the voltage Vin at the terminal so that it is closer to or equal to Vusb 1040. Figure 11 , at time 1 (1110), the voltage Vin is shown to be lower than Vusb. At this point, connecting the external power supply Vusb 1040 to the charge pump circuit 1010 by turning on and off the switch 1050 may result in an undesirable inrush current. However, by advantageously operating the charge pump circuit 1010 as a boost converter, the voltage Vin can be increased so that it is closer to Vusb at time 2 (1120), or equal to Vusb at time 3 (1130). In contrast, connecting the external power supply Vusb 1040 to the charge pump circuit 1010 by turning on and off the switch 1050 at these times can result in minimized inrush current or elimination of inrush current. Subsequently, the charge pump circuit 1010 can operate as a buck converter, for example, reducing the voltage Vin at the terminal to the voltage VOUT.

[0056] The disclosed embodiments can be further described by the exemplary clauses set forth below:

[0057] Clause Set A1

[0058] 1. A method for energizing a charge pump circuit,

[0059] The charge pump circuit is capable of operating as a boost converter and comprises:

[0060] a plurality of phase switches and series switches, each of the switches including a gate terminal coupled to a gate driver circuit;

[0061] a plurality of flying capacitors, each flying capacitor coupled between at least one phase switch and the series switch;

[0062] a first set of voltage regulators, each voltage regulator in the first set of voltage regulators being configured to drive one of the gate driver circuits coupled to one of the phase switches, and each voltage regulator in the first set of voltage regulators being configured to draw a supply voltage from a series side terminal of at least one of the flying capacitors or a boost converter input terminal; and

[0063] a second set of voltage regulators, each voltage regulator in the second set of voltage regulators being configured to drive one of the gate driver circuits coupled to one of the series switches, and each voltage regulator in the second set of voltage regulators being configured to draw a supply voltage from a series side terminal of at least one of the flying capacitors or a boost converter output terminal,

[0064] The method comprises:

[0065] providing an input voltage at the boost converter input terminal without operating the phase switch or the series switch;

[0066] determining that the supply voltage of the first set of voltage regulators is sufficient to operate the phase switches in at least a reduced gate drive mode;

[0067] after determining that the supply voltage of the first set of voltage regulators is sufficient to operate the phase switches, operating the phase switches without operating the series switches;

[0068] determining that the supply voltage of one of the second set of voltage regulators is sufficient to operate its corresponding series switch in at least a reduced gate drive mode; and

[0069] In determining the power supply of the one voltage regulator in the second group of voltage regulators

[0070] 2. The method of clause 1, wherein determining that the supply voltage of the first set of voltage regulators is sufficient to operate the phase switches in at least the reduced gate drive mode comprises determining that the supply voltage of a voltage regulator in the first set of voltage regulators exceeds the sum of its dropout voltage and the source voltage of its associated phase switch.

[0071] 3. The method of clause 2, wherein determining that the supply voltage of one of the first set of voltage regulators exceeds the sum of its dropout voltage and the source voltage of its associated phase switch is performed using a comparator circuit.

[0072] 4. The method of any of the preceding clauses, wherein at least one of the first set of voltage regulators is configured to draw its supply voltage via a bootstrap capacitor or a bootstrap circuit.

[0073] 5. The method of clause 4, wherein the at least one of the first set of voltage regulators is configured to draw its supply voltage from the boost converter input terminal via the bootstrap capacitor or the bootstrap circuit.

[0074] 6. The method of any of the preceding clauses, wherein operating the phase switch without operating the series switch comprises operating the phase switch in the reduced gate drive mode.

[0075] 7. A method according to any of the preceding clauses,

[0076] Wherein, the phase switch is an N-channel MOSFET;

[0077] Wherein, the charge pump circuit further comprises a plurality of P-channel MOSFETs, each P-channel MOSFET being electrically coupled in parallel with a corresponding N-channel MOSFET phase switch; and

[0078] Wherein operating the phase switch without operating the series switch comprises operating the P-channel MOSFET using the supply voltage of the first set of voltage regulators drawn from the boost converter input terminal.

[0079] 8. The method of any preceding clause, wherein determining that the supply voltage of the one voltage regulator of the second group of voltage regulators is sufficient to operate its corresponding series switch in at least the reduced gate drive mode comprises:

[0080] It is determined that the supply voltage of the one voltage regulator of the second group of voltage regulators exceeds the sum of its dropout voltage and the source voltage of its associated series switch.

[0081] 9. The method of clause 8, wherein determining that the supply voltage of the one voltage regulator of the second group of voltage regulators exceeds the sum of its dropout voltage and the source voltage of its associated series switch is performed using a comparator circuit.

[0082] 10. The method of any of the preceding clauses, wherein at least one of the second set of voltage regulators is configured to draw its supply voltage via a bootstrap capacitor or a bootstrap circuit.

[0083] 11. The method of clause 10, wherein the at least one of the second set of voltage regulators is configured to draw its supply voltage from the boost converter output terminal via the bootstrap capacitor or the bootstrap circuit.

[0084] 12. The method of any preceding clause, wherein operating the corresponding series switch comprises operating the corresponding series switch in the reduced gate drive mode.

[0085] 13. A method according to any of the preceding clauses, further comprising:

[0086] determining that the supply voltages of a first subset of the second set of voltage regulators are sufficient to operate their corresponding series switches in at least a reduced gate drive mode;

[0087] determining that the supply voltages of a second subset of the second group of voltage regulators are insufficient to operate their corresponding series switches in at least a reduced gate drive mode; and

[0088] The series switches corresponding to the first subset of the second group of voltage regulators are operated, while the series switches corresponding to the second subset of the second group of voltage regulators are not operated.

[0089] 14. The method of any of the preceding clauses, wherein the charge pump circuit is also operable as a buck converter after it has been powered on.

[0090] 15. A charge pump circuit configured to perform the method according to any of the preceding clauses.

[0091] 16. The charge pump circuit of clause 15, wherein the charge pump circuit is an integrated circuit.

[0092] 17. The charge pump circuit of clause 15, wherein the charge pump circuit is an integrated circuit that does not include the flying capacitor.

[0093] Clause Set A2

[0094] 1. An integrated circuit comprising:

[0095] A charge pump circuit capable of operating as a boost converter, and comprising:

[0096] a plurality of phase switches and series switches, each of the switches including a gate terminal coupled to a gate driver circuit, wherein the phase switches and series switches are configured to be coupled to a plurality of flying capacitors, each flying capacitor configured to be coupled between at least one phase switch and the series switch;

[0097] a first set of voltage regulators, each voltage regulator in the first set of voltage regulators being configured to drive one of the gate driver circuits coupled to one of the phase switches, and each voltage regulator in the first set of voltage regulators being configured to draw a supply voltage from a series side terminal of at least one of the flying capacitors or a boost converter input terminal; and

[0098] a second set of voltage regulators, each voltage regulator in the second set of voltage regulators being configured to drive one of the gate driver circuits coupled to one of the series switches, and each voltage regulator in the second set of voltage regulators being configured to draw a supply voltage from a series side terminal of at least one of the flying capacitors or a boost converter output terminal;

[0099] Wherein, the charge pump circuit is configured as follows:

[0100] receiving an input voltage at the boost converter input terminal without operating the phase switch or the series switch,

[0101] determining that the supply voltage of the first set of voltage regulators is sufficient to operate the phase switches in at least a reduced gate drive mode,

[0102] after determining that the supply voltage of the first group of voltage regulators is sufficient to operate the phase switches, operating the phase switches without operating the series switches,

[0103] determining that the supply voltage of one of the second set of voltage regulators is sufficient to operate its corresponding series switch in at least a reduced gate drive mode, and

[0104] After determining that the supply voltage of the one voltage regulator in the second group of voltage regulators is sufficient to operate the corresponding series switch, the corresponding series switch is operated.

[0105] 2. The integrated circuit of clause 1, wherein determining that the supply voltage of the first set of voltage regulators is sufficient to operate the phase switches in at least the reduced gate drive mode comprises:

[0106] It is determined that the supply voltage of one of the first group of voltage regulators exceeds the sum of its dropout voltage and the source voltage of its associated phase switch.

[0107] 3. The integrated circuit of clause 2, further comprising:

[0108] A comparator circuit is configured to determine whether the supply voltage of one of the first group of voltage regulators exceeds the sum of its dropout voltage and the source voltage of its associated phase switch.

[0109] 4. An integrated circuit according to any of the preceding clauses, further comprising:

[0110] A bootstrap capacitor or a bootstrap circuit is configured to provide a supply voltage to at least one of the first set of voltage regulators.

[0111] 5. The integrated circuit of clause 4, wherein the bootstrap capacitor or the bootstrap circuit is configured to provide a supply voltage from the boost converter input terminal to at least one of the first set of voltage regulators.

[0112] 6. An integrated circuit as recited in any preceding clause, wherein operating the phase switch without operating the series switch comprises operating the phase switch in the reduced gate drive mode.

[0113] 7. An integrated circuit according to any of the preceding clauses,

[0114] Wherein, the phase switch is an N-channel MOSFET;

[0115] Wherein, the charge pump circuit further comprises a plurality of P-channel MOSFETs, each P-channel MOSFET being electrically coupled in parallel with a corresponding N-channel MOSFET phase switch; and

[0116] Wherein operating the phase switch without operating the series switch comprises operating the P-channel MOSFET using the supply voltage of the first set of voltage regulators drawn from the boost converter input terminal.

[0117] 8. An integrated circuit according to any of the preceding clauses, wherein determining that the supply voltage of the one voltage regulator of the second group of voltage regulators is sufficient to operate its corresponding series switch in at least the reduced gate drive mode comprises:

[0118] It is determined that the supply voltage of the one voltage regulator of the second group of voltage regulators exceeds the sum of its dropout voltage and the source voltage of its associated series switch.

[0119] 9. The integrated circuit of clause 8, further comprising:

[0120] A comparator circuit is configured to determine whether the supply voltage of the one voltage regulator of the second group of voltage regulators exceeds the sum of its dropout voltage and the source voltage of its associated series switch.

[0121] 10. An integrated circuit according to any preceding clause, further comprising:

[0122] A bootstrap capacitor or a bootstrap circuit is configured to provide a supply voltage to at least one of the second set of voltage regulators.

[0123] 11. The integrated circuit of clause 10, wherein the bootstrap capacitor or the bootstrap circuit is configured to provide a supply voltage from the boost converter output terminal to at least one of the second set of voltage regulators.

[0124] 12. An integrated circuit as recited in any preceding clause, wherein operating the corresponding series switch comprises operating the corresponding series switch in the reduced gate drive mode.

[0125] 13. An integrated circuit according to any preceding clause, wherein the charge pump circuit is further configured to:

[0126] determining that the supply voltages of a first subset of the second set of voltage regulators are sufficient to operate their corresponding series switches in at least a reduced gate drive mode;

[0127] determining that the supply voltages of a second subset of the second group of voltage regulators are insufficient to operate their corresponding series switches in at least a reduced gate drive mode; and

[0128] The series switches corresponding to the first subset of the second group of voltage regulators are operated, while the series switches corresponding to the second subset of the second group of voltage regulators are not operated.

[0129] 14. An integrated circuit according to any of the preceding clauses, wherein the charge pump circuit is further capable of operating as a buck converter after it has been powered on.

[0130] Clause Set A3

[0131] 1. A power converter device comprising:

[0132] A charge pump circuit capable of operating as a boost converter, and comprising:

[0133] a plurality of phase switches and series switches, each of the switches including a gate terminal coupled to a gate driver circuit;

[0134] a plurality of flying capacitors, each flying capacitor coupled between at least one phase switch and the series switch;

[0135] a first set of voltage regulators, each voltage regulator in the first set of voltage regulators being configured to drive one of the gate driver circuits coupled to one of the phase switches, and each voltage regulator in the first set of voltage regulators being configured to draw a supply voltage from a series side terminal of at least one of the flying capacitors or a boost converter input terminal; and

[0136] a second set of voltage regulators, each voltage regulator in the second set of voltage regulators being configured to drive one of the gate driver circuits coupled to one of the series switches, and each voltage regulator in the second set of voltage regulators being configured to draw a supply voltage from a series side terminal of at least one of the flying capacitors or a boost converter output terminal;

[0137] Wherein, the charge pump circuit is configured as follows:

[0138] receiving an input voltage at the boost converter input terminal without operating the phase switch or the series switch,

[0139] determining that the supply voltage of the first set of voltage regulators is sufficient to operate the phase switches in at least a reduced gate drive mode,

[0140] after determining that the supply voltage of the first group of voltage regulators is sufficient to operate the phase switches, operating the phase switches without operating the series switches,

[0141] determining that the supply voltage of one of the second set of voltage regulators is sufficient to operate its corresponding series switch in at least a reduced gate drive mode, and

[0142] In determining the power supply of the one voltage regulator in the second group of voltage regulators

[0143] 2. The apparatus of clause 1 , wherein determining that the supply voltage of the first set of voltage regulators is sufficient to operate the phase switches in at least the reduced gate drive mode comprises determining that the supply voltage of a voltage regulator in the first set of voltage regulators exceeds the sum of its voltage drop and the source voltage of its associated phase switch.

[0144] 3. The apparatus of clause 2, further comprising:

[0145] A comparator circuit is configured to determine whether the supply voltage of one of the first group of voltage regulators exceeds the sum of its dropout voltage and the source voltage of its associated phase switch.

[0146] 4. The apparatus according to any of the preceding clauses, further comprising:

[0147] A bootstrap capacitor or a bootstrap circuit is configured to provide a supply voltage to at least one of the first set of voltage regulators.

[0148] 5. The apparatus of clause 4, wherein the bootstrap capacitor or the bootstrap circuit is configured to provide a supply voltage from the boost converter input terminal to at least one of the first set of voltage regulators.

[0149] 6. The apparatus of any preceding clause, wherein operating the phase switch without operating the series switch comprises operating the phase switch in the reduced gate drive mode.

[0150] 7. A device according to any of the preceding clauses,

[0151] Wherein, the phase switch is an N-channel MOSFET;

[0152] Wherein, the charge pump circuit further comprises a plurality of P-channel MOSFETs, each P-channel MOSFET being electrically coupled in parallel with a corresponding N-channel MOSFET phase switch; and

[0153] Wherein operating the phase switch without operating the series switch comprises operating the P-channel MOSFET using the supply voltage of the first set of voltage regulators drawn from the boost converter input terminal.

[0154] 8. The apparatus of any preceding clause, wherein determining that the supply voltage of the one voltage regulator of the second group of voltage regulators is sufficient to operate its corresponding series switch in at least the reduced gate drive mode comprises:

[0155] It is determined that the supply voltage of the one voltage regulator of the second group of voltage regulators exceeds the sum of its dropout voltage and the source voltage of its associated series switch.

[0156] 9. The apparatus of clause 8, further comprising:

[0157] A comparator circuit is configured to determine whether the supply voltage of the one voltage regulator of the second group of voltage regulators exceeds the sum of its dropout voltage and the source voltage of its associated series switch.

[0158] 10. The apparatus according to any of the preceding clauses, further comprising:

[0159] A bootstrap capacitor or a bootstrap circuit is configured to provide a supply voltage to at least one of the second set of voltage regulators.

[0160] 11. The apparatus of clause 10, wherein the bootstrap capacitor or the bootstrap circuit is configured to provide a supply voltage from the boost converter output terminal to at least one of the second set of voltage regulators.

[0161] 12. The apparatus of any preceding clause, wherein operating the corresponding series switch comprises operating the corresponding series switch in the reduced gate drive mode.

[0162] 13. The apparatus of any preceding clause, wherein the charge pump circuit is further configured to:

[0163] determining that the supply voltages of a first subset of the second set of voltage regulators are sufficient to operate their corresponding series switches in at least a reduced gate drive mode;

[0164] determining that the supply voltages of a second subset of the second group of voltage regulators are insufficient to operate their corresponding series switches in at least a reduced gate drive mode; and

[0165] The series switches corresponding to the first subset of the second group of voltage regulators are operated, while the series switches corresponding to the second subset of the second group of voltage regulators are not operated.

[0166] 14. The apparatus of any preceding clause, wherein the charge pump circuit is further operable as a buck converter after it has been powered on.

[0167] Clause Set B1

[0168] 1. A method for energizing a charge pump circuit,

[0169] The charge pump circuit is capable of operating as a boost converter and comprises:

[0170] a plurality of phase switches and series switches, each of the switches including a gate terminal coupled to a gate driver circuit;

[0171] a plurality of flying capacitors, each flying capacitor coupled between at least one phase switch and the series switch;

[0172] a first set of voltage regulators, each voltage regulator in the first set of voltage regulators being configured to drive one of the gate driver circuits coupled to one of the phase switches, and each voltage regulator in the first set of voltage regulators being configured to draw a supply voltage from a series side terminal of at least one of the flying capacitors or a boost converter input terminal; and

[0173] a second set of voltage regulators, each voltage regulator in the second set of voltage regulators being configured to drive one of the gate driver circuits coupled to one of the series switches, and each voltage regulator in the second set of voltage regulators being configured to draw a supply voltage from a series side terminal of at least one of the flying capacitors or a boost converter output terminal,

[0174] The method comprises:

[0175] providing an input voltage at the boost converter input terminal without operating the phase switch or the series switch;

[0176] determining that the supply voltage of the first set of voltage regulators is sufficient to operate the phase switches in at least a reduced gate drive mode;

[0177] after determining that the supply voltage of the first set of voltage regulators is sufficient to operate the phase switches, operating the phase switches without operating the series switches;

[0178] determining that a voltage at an output terminal of the boost converter exceeds a threshold voltage;

[0179] after determining that the voltage at the boost converter output terminal exceeds the threshold voltage, not operating the phase switch and the series switch for a predetermined period of time; and

[0180] After the predetermined period of time, determining that the supply voltage of the second set of voltage regulators is sufficient to operate the series switches in at least a reduced gate drive mode, and

[0181] After determining that the supply voltage of the second group of voltage regulators is sufficient to operate the series switches, both the phase switches and the series switches are operated.

[0182] 2. The method of clause 1 , wherein determining that the supply voltage of the first group of voltage regulators is sufficient to operate the phase switches in at least the reduced gate drive mode comprises determining that the supply voltage of one of the first group of voltage regulators exceeds the sum of its dropout voltage and the source voltage of its associated phase switch.

[0183] 3. The method of clause 2, wherein determining that the supply voltage of one of the first set of voltage regulators exceeds the sum of its dropout voltage and the source voltage of its associated phase switch is performed using a comparator circuit.

[0184] 4. The method of any of the preceding clauses, wherein at least one of the first set of voltage regulators is configured to draw its supply voltage via a bootstrap capacitor or a bootstrap circuit.

[0185] 5. The method of clause 4, wherein at least one of the first set of voltage regulators is configured to draw its supply voltage from the boost converter input terminal via the bootstrap capacitor or the bootstrap circuit.

[0186] 6. The method of any of the preceding clauses, wherein operating the phase switch without operating the series switch comprises operating the phase switch in the reduced gate drive mode.

[0187] 7. A method according to any of the preceding clauses,

[0188] Wherein, the phase switch is an N-channel MOSFET;

[0189] Wherein, the charge pump circuit further comprises a plurality of P-channel MOSFETs, each P-channel MOSFET being electrically coupled in parallel with a corresponding N-channel MOSFET phase switch; and

[0190] Wherein operating the phase switch without operating the series switch comprises operating the P-channel MOSFET using the supply voltage of the first set of voltage regulators drawn from the boost converter input terminal.

[0191] 8. A method according to any of the preceding clauses, wherein determining that the voltage at the boost converter output terminal exceeds a threshold voltage is performed using a comparator circuit.

[0192] 9. The method of any preceding clause, wherein determining that the supply voltage of the second set of voltage regulators is sufficient to operate the series switches at least in a reduced gate drive mode comprises:

[0193] It is determined that the supply voltage of the one voltage regulator of the second group of voltage regulators exceeds the sum of its dropout voltage and the source voltage of its associated series switch.

[0194] 10. A method according to any clause 9, wherein determining that the supply voltage of the one voltage regulator of the second group of voltage regulators exceeds the sum of its dropout voltage and the source voltage of its associated series switch is performed using a comparator circuit.

[0195] 11. The method of any of the preceding clauses, wherein at least one of the second set of voltage regulators is configured to draw its supply voltage via a bootstrap capacitor or a bootstrap circuit.

[0196] 12. The method of clause 11, wherein at least one of the second set of voltage regulators is configured to draw its supply voltage from the boost converter output terminal via the bootstrap capacitor or the bootstrap circuit.

[0197] 13. The method of any of the preceding clauses, wherein operating both the phase switch and the series switch comprises operating both the phase switch and the series switch in the reduced gate drive mode.

[0198] 14. The method of any of the preceding clauses, wherein the charge pump circuit is also operable as a buck converter after it has been powered on.

[0199] 15. A charge pump circuit configured to perform the method according to any of the preceding clauses.

[0200] 16. The charge pump circuit of clause 15, wherein the charge pump circuit is an integrated circuit.

[0201] 17. The charge pump circuit of clause 15, wherein the charge pump circuit is an integrated circuit that does not include the flying capacitor.

[0202] Clause Set B2

[0203] 1. An integrated circuit comprising:

[0204] A charge pump circuit capable of operating as a boost converter, and comprising:

[0205] a plurality of phase switches and series switches, each of the switches including a gate terminal coupled to a gate driver circuit, wherein the phase switches and series switches are configured to be coupled to a plurality of flying capacitors, each flying capacitor configured to be coupled between at least one phase switch and the series switch;

[0206] a first set of voltage regulators, each voltage regulator in the first set of voltage regulators being configured to drive one of the gate driver circuits coupled to one of the phase switches, and each voltage regulator in the first set of voltage regulators being configured to draw a supply voltage from a series side terminal of at least one of the flying capacitors or a boost converter input terminal; and

[0207] a second set of voltage regulators, each of the second set of voltage regulators configured to drive one of the gate driver circuits coupled to one of the series switches, and each of the second set of voltage regulators configured to draw a supply voltage from a series side terminal of at least one of the flying capacitors or a boost converter output terminal;

[0208] Wherein, the charge pump circuit is configured as follows:

[0209] receiving an input voltage at the boost converter input terminal without operating the phase switch or the series switch;

[0210] determining that the supply voltage of the first set of voltage regulators is sufficient to operate the phase switches in at least a reduced gate drive mode;

[0211] after determining that the supply voltage of the first set of voltage regulators is sufficient to operate the phase switches, operating the phase switches without operating the series switches;

[0212] determining that a voltage at an output terminal of the boost converter exceeds a threshold voltage;

[0213] after determining that the voltage at the boost converter output terminal exceeds the threshold voltage, not operating the phase switch and the series switch for a predetermined period of time; and

[0214] After the predetermined period of time, determining that the supply voltage of the second set of voltage regulators is sufficient to operate the series switches in at least a reduced gate drive mode, and

[0215] After determining that the supply voltage of the second group of voltage regulators is sufficient to operate the series switches, both the phase switches and the series switches are operated.

[0216] 2. The integrated circuit of clause 1, wherein determining that the supply voltage of the first set of voltage regulators is sufficient to operate the phase switches in at least the reduced gate drive mode comprises:

[0217] It is determined that the supply voltage of one of the first group of voltage regulators exceeds the sum of its dropout voltage and the source voltage of its associated phase switch.

[0218] 3. The integrated circuit of clause 2, further comprising:

[0219] A comparator circuit is configured to determine whether the supply voltage of one of the first group of voltage regulators exceeds the sum of its dropout voltage and the source voltage of its associated phase switch.

[0220] 4. An integrated circuit according to any of the preceding clauses, further comprising:

[0221] A bootstrap capacitor or a bootstrap circuit is configured to provide a supply voltage to at least one of the first set of voltage regulators.

[0222] 5. The integrated circuit of clause 4, wherein the bootstrap capacitor or the bootstrap circuit is configured to provide a supply voltage from the boost converter input terminal to at least one of the first set of voltage regulators.

[0223] 6. An integrated circuit as recited in any preceding clause, wherein operating the phase switch without operating the series switch comprises operating the phase switch in the reduced gate drive mode.

[0224] 7. An integrated circuit according to any of the preceding clauses,

[0225] Wherein, the phase switch is an N-channel MOSFET;

[0226] Wherein, the charge pump circuit further comprises a plurality of P-channel MOSFETs, each P-channel MOSFET being electrically coupled in parallel with a corresponding N-channel MOSFET phase switch; and

[0227] Wherein operating the phase switch without operating the series switch comprises operating the P-channel MOSFETs using the supply voltage of the first set of voltage regulators drawn from the boost converter input terminal.

[0228] 8. An integrated circuit according to any preceding clause, further comprising:

[0229] A comparator circuit is configured to determine whether a voltage at an output terminal of the boost converter exceeds a threshold voltage.

[0230] 9. An integrated circuit according to any preceding clause, wherein determining that the supply voltage of the second set of voltage regulators is sufficient to operate the series switch in at least a reduced gate drive mode comprises:

[0231] It is determined that the supply voltage of the one voltage regulator of the second group of voltage regulators exceeds the sum of its dropout voltage and the source voltage of its associated series switch.

[0232] 10. An integrated circuit according to any one of clauses 9, further comprising:

[0233] A comparator circuit is configured to determine whether the supply voltage of the one voltage regulator of the second group of voltage regulators exceeds the sum of its dropout voltage and the source voltage of its associated series switch.

[0234] 11. An integrated circuit according to any preceding clause, further comprising:

[0235] A bootstrap capacitor or a bootstrap circuit is configured to provide a supply voltage to at least one of the second set of voltage regulators.

[0236] 12. The integrated circuit of clause 11, wherein the bootstrap capacitor or the bootstrap circuit is configured to provide a supply voltage from the boost converter output terminal to at least one of the second set of voltage regulators.

[0237] 13. The integrated circuit of any preceding clause, wherein operating both the phase switch and the series switch comprises operating both the phase switch and the series switch in the reduced gate drive mode.

[0238] 14. An integrated circuit according to any of the preceding clauses, wherein the charge pump circuit is further capable of operating as a buck converter after it has been powered on.

[0239] Clause Set B3

[0240] 1. A power converter device comprising:

[0241] A charge pump circuit capable of operating as a boost converter, and comprising:

[0242] a plurality of phase switches and series switches, each of the switches including a gate terminal coupled to a gate driver circuit;

[0243] a plurality of flying capacitors, each flying capacitor coupled between at least one phase switch and the series switch;

[0244] a first set of voltage regulators, each voltage regulator in the first set of voltage regulators being configured to drive one of the gate driver circuits coupled to one of the phase switches, and each voltage regulator in the first set of voltage regulators being configured to draw a supply voltage from a series side terminal of at least one of the flying capacitors or a boost converter input terminal; and

[0245] a second set of voltage regulators, each of the second set of voltage regulators being configured to drive one of the gate driver circuits coupled to one of the series switches, and each of the second set of voltage regulators being configured to receive power from the flying capacitor;

[0246] The series side terminal of at least one of the boost converters or the boost converter output terminal draws the supply voltage; wherein the charge pump circuit is configured to:

[0247] receiving an input voltage at the boost converter input terminal without operating the phase switch or the series switch;

[0248] determining that the supply voltage of the first set of voltage regulators is sufficient to operate the phase switches in at least a reduced gate drive mode;

[0249] after determining that the supply voltage of the first set of voltage regulators is sufficient to operate the phase switches, operating the phase switches without operating the series switches;

[0250] determining that a voltage at an output terminal of the boost converter exceeds a threshold voltage;

[0251] after determining that the voltage at the boost converter output terminal exceeds the threshold voltage, not operating the phase switch and the series switch for a predetermined period of time; and

[0252] After the predetermined period of time, determining that the supply voltage of the second set of voltage regulators is sufficient to operate the series switches in at least a reduced gate drive mode, and

[0253] After determining that the supply voltage of the second group of voltage regulators is sufficient to operate the series switches, both the phase switches and the series switches are operated.

[0254] 2. The apparatus of clause 1 , wherein determining that the supply voltage of the first group of voltage regulators is sufficient to operate the phase switches in at least the reduced gate drive mode comprises determining that the supply voltage of one of the first group of voltage regulators exceeds the sum of its dropout voltage and a source voltage of its associated phase switch.

[0255] 3. The apparatus of clause 2, further comprising:

[0256] A comparator circuit is configured to determine whether the supply voltage of one of the first group of voltage regulators exceeds the sum of its dropout voltage and the source voltage of its associated phase switch.

[0257] 4. The apparatus according to any of the preceding clauses, further comprising:

[0258] A bootstrap capacitor or a bootstrap circuit is configured to provide a supply voltage to at least one of the first set of voltage regulators.

[0259] 5. The apparatus of clause 4, wherein the bootstrap capacitor or the bootstrap circuit is configured to provide a supply voltage from the boost converter input terminal to at least one of the first set of voltage regulators.

[0260] 6. The apparatus of any preceding clause, wherein operating the phase switch without operating the series switch comprises operating the phase switch in the reduced gate drive mode.

[0261] 7. A device according to any of the preceding clauses,

[0262] Wherein, the phase switch is an N-channel MOSFET;

[0263] Wherein, the charge pump circuit further comprises a plurality of P-channel MOSFETs, each P-channel MOSFET being electrically coupled in parallel with a corresponding N-channel MOSFET phase switch; and

[0264] Wherein operating the phase switch without operating the series switch comprises operating the P-channel MOSFET using the supply voltage of the first set of voltage regulators drawn from the boost converter input terminal.

[0265] 8. The apparatus according to any of the preceding clauses, further comprising:

[0266] A comparator circuit is configured to determine whether a voltage at an output terminal of the boost converter exceeds a threshold voltage.

[0267] 9. The apparatus of any preceding clause, wherein determining that the supply voltage of the second set of voltage regulators is sufficient to operate the series switches in at least a reduced gate drive mode comprises:

[0268] It is determined that the supply voltage of the one voltage regulator of the second group of voltage regulators exceeds the sum of its dropout voltage and the source voltage of its associated series switch.

[0269] 10. The apparatus according to any of clauses 9, further comprising:

[0270] A comparator circuit is configured to determine whether the supply voltage of the one voltage regulator of the second group of voltage regulators exceeds the sum of its dropout voltage and the source voltage of its associated series switch.

[0271] 11. The apparatus according to any of the preceding clauses, further comprising:

[0272] A bootstrap capacitor or a bootstrap circuit is configured to provide a supply voltage to at least one of the second set of voltage regulators.

[0273] 12. The apparatus of clause 11, wherein the bootstrap capacitor or the bootstrap circuit is configured to provide a supply voltage from the boost converter output terminal to at least one of the second set of voltage regulators.

[0274] 13. The apparatus of any preceding clause, wherein operating both the phase switch and the series switch comprises operating both the phase switch and the series switch in the reduced gate drive mode.

[0275] 14. The apparatus of any preceding clause, wherein the charge pump circuit is further operable as a buck converter after it has been powered on.

[0276] In the foregoing description, embodiments have been described with reference to many specific details, which may vary depending on the implementation. Certain adjustments and modifications to the described embodiments may be made. Other embodiments will be apparent to those skilled in the art given the description and practice of the disclosure disclosed herein. It is also intended that the order of steps shown in the accompanying drawings is for illustrative purposes only and is not intended to be limited to any particular order of steps. Therefore, it will be understood by those skilled in the art that these steps may be performed in different orders when implementing the same method.

[0277] It should be understood that, for the sake of clarity, certain features of the specification described in the context of separate embodiments may also be provided in combination in a single embodiment. Conversely, various features of the specification described in the context of a single embodiment for the sake of brevity may also be provided individually or in any suitable subcombination or as appropriate in any other described embodiment of the specification. Certain features described in the context of various embodiments are not to be considered essential features of those embodiments, unless the embodiment will not function without those elements.

[0278] The terms used in this specification generally have their ordinary meanings in the art and in the specific context in which each term is used. The use of examples in this specification, including examples of any term discussed herein, is illustrative only and in no way limits the scope and meaning of the present disclosure or any exemplified term. Likewise, the present disclosure is not limited to the various embodiments given in this specification.

[0279] Although the terms "first," "second," etc. may be used herein to describe various elements, these elements should not be limited by these terms. These terms are used to distinguish one element from another. For example, a first element may be referred to as a second element, and similarly, a second element may be referred to as a first element, without departing from the scope of the embodiments. As used herein, the term "and / or" includes any and all combinations of one or more of the associated listed items.

[0280] For ease of description, spatially relative terms such as "below," "lower," "above," "upper," etc. may be used herein to describe the relationship of one element or feature to another element or feature illustrated in the accompanying drawings. Spatially relative terms are intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the accompanying drawings. The device may be otherwise oriented (rotated 90 degrees or at other orientations), and the spatially relative descriptors used herein should be interpreted accordingly.

[0281] In this specification, the term “coupled” may also be referred to as “electrically coupled,” and the term “connected” may also be referred to as “electrically connected.” “Coupled” and “connected” may also be used to indicate that two or more elements cooperate or interact with each other.

[0282] While embodiments of the present disclosure may address some challenges and provide some benefits, the problems and features set forth herein are intended to be exemplary and not to limit the claims or scope of the present disclosure. In fact, the disclosed embodiments may address challenges and provide benefits not explicitly recited.

Claims

1. A method for energizing a charge pump circuit, The charge pump circuit is capable of operating as a boost converter and comprises: a plurality of phase switches and series switches, each of the switches including a gate terminal coupled to a gate driver circuit; a plurality of flying capacitors, each flying capacitor coupled between at least one phase switch and the series switch; a first set of voltage regulators, each voltage regulator in the first set of voltage regulators being configured to drive one of the gate driver circuits coupled to one of the phase switches, and each voltage regulator in the first set of voltage regulators being configured to draw a supply voltage from a series side terminal of at least one of the flying capacitors or a boost converter input terminal; as well as a second set of voltage regulators, each of the second set of voltage regulators being configured to drive one of the gate driver circuits coupled to one of the series switches, and each of the second set of voltage regulators being configured to draw a supply voltage from a series side terminal of at least one of the flying capacitors or a boost converter output terminal, The method comprises: providing an input voltage at the boost converter input terminal without operating the phase switch or the series switch; determining that the supply voltage of the first set of voltage regulators is sufficient to operate the phase switches in at least a reduced gate drive mode; after determining that the supply voltage of the first set of voltage regulators is sufficient to operate the phase switches, operating the phase switches without operating the series switches; determining that the supply voltage of one of the second set of voltage regulators is sufficient to operate its corresponding series switch in at least a reduced gate drive mode; and After determining that the supply voltage of the one voltage regulator in the second group of voltage regulators is sufficient to operate the corresponding series switch, the corresponding series switch is operated.

2. The method according to claim 1, wherein Determining that the supply voltage of the first set of voltage regulators is sufficient to operate the phase switches in at least the reduced gate drive mode includes: It is determined that the supply voltage of one of the first group of voltage regulators exceeds the sum of its dropout voltage and the source voltage of its associated phase switch.

3. The method according to claim 2, wherein: Determining that the supply voltage of one of the first set of voltage regulators exceeds the sum of its dropout voltage and the source voltage of its associated phase switch is performed using a comparator circuit.

4. A method according to any one of the preceding claims, wherein At least one of the first set of voltage regulators is configured to draw its supply voltage via a bootstrap capacitor or a bootstrap circuit.

5. The method according to claim 4, wherein At least one of the first set of voltage regulators is configured to draw its supply voltage from the boost converter input terminal via the bootstrap capacitor or the bootstrap circuit.

6. A method according to any one of the preceding claims, wherein Operating the phase switch without operating the series switch includes operating the phase switch in the reduced gate drive mode.

7. The method according to any one of the preceding claims, in, The phase switch is an N-channel MOSFET; Wherein, the charge pump circuit further comprises a plurality of P-channel MOSFETs, each P-channel MOSFET being electrically coupled in parallel with a corresponding N-channel MOSFET phase switch; and Wherein operating the phase switch without operating the series switch comprises operating the P-channel MOSFET using the supply voltage of the first set of voltage regulators drawn from the boost converter input terminal.

8. A method according to any one of the preceding claims, wherein Determining that the supply voltage of the one voltage regulator in the second group of voltage regulators is sufficient to operate its corresponding series switch in at least the reduced gate drive mode includes: It is determined that the supply voltage of the one voltage regulator of the second group of voltage regulators exceeds the sum of its dropout voltage and the source voltage of its associated series switch.

9. The method according to claim 8, wherein Determining that the supply voltage of the one voltage regulator of the second group of voltage regulators exceeds the sum of its dropout voltage and the source voltage of its associated series switch is performed using a comparator circuit.

10. A method according to any one of the preceding claims, wherein At least one of the second set of voltage regulators is configured to draw its supply voltage via a bootstrap capacitor or a bootstrap circuit.

11. The method according to claim 10, wherein: At least one of the second set of voltage regulators is configured to draw its supply voltage from the boost converter output terminal via the bootstrap capacitor or the bootstrap circuit.

12. A method according to any one of the preceding claims, wherein Operating the corresponding series switch includes operating the corresponding series switch in the reduced gate drive mode.

13. The method according to any one of the preceding claims, further comprising: determining that the supply voltages of a first subset of the second set of voltage regulators are sufficient to operate their corresponding series switches in at least a reduced gate drive mode; determining that the supply voltages of a second subset of the second group of voltage regulators are insufficient to operate their corresponding series switches in at least a reduced gate drive mode; as well as The series switches corresponding to the first subset of the second group of voltage regulators are operated, while the series switches corresponding to the second subset of the second group of voltage regulators are not operated.

14. A method according to any one of the preceding claims, wherein The charge pump circuit can also operate as a buck converter after it has been powered on.

15. A charge pump circuit configured to perform the method according to any one of the preceding claims.

16. The charge pump circuit according to claim 15, wherein: The charge pump circuit is an integrated circuit.

17. The charge pump circuit according to claim 15, wherein: The charge pump circuit is an integrated circuit that does not include the flying capacitor.

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