Driving circuit of power device, control method and power chip

Abstract

The embodiment of the invention provides a driving circuit of a power device, a control method and a power chip, and the driving circuit at least comprises a first switch module, a second switch module, a third switch module, a fourth switch module, a fifth switch module and an energy processing module, the first switch module and the second switch module are respectively connected with the energy processing module, the energy processing module is also respectively connected with the third switch module and the fifth switch module, the second switch module is connected with the fifth switch module through the fourth switch module, the fifth switch module is connected with the power device, and the power device is also connected with the driving module; the on-off state of the power device is controlled by controlling the on-off of the third switch module and the fifth switch module, so that the power device driving circuit structure which does not need to use more off-chip passive devices, is high in integration level and can dynamically switch working modes is provided, the cost is saved, and dual-mode switching control is also realized.

Description

Technical Field

[0001] The present application relates to the technical field of electronic circuits, and in particular to a driving circuit, a control method, and a power chip for a power device. Background Art

[0002] In recent years, gallium nitride (GaN) devices have been widely used in high-frequency, high-efficiency power electronics systems due to their excellent switching performance, high breakdown voltage, and low on-resistance. Among the numerous GaN devices, depletion-mode (D-mode) GaN devices have gradually attracted attention from both the research and industry communities due to their more stable electrical performance and greater voltage margin. However, since D-mode GaN devices are normally-on devices, a negative gate voltage is required to achieve shutdown during the driving process. This typically requires an additional negative voltage supply and additional off-chip passive components, increasing system complexity and cost. Therefore, how to achieve cost-effective control of gallium nitride (GaN) devices is an urgent problem that needs to be solved. Summary of the Invention

[0003] The purpose of some embodiments of the present application is to provide a driving circuit, a control method and a power chip for a power device. Through the technical solutions of the embodiments of the present application, a driving circuit for a power device is provided, which comprises at least: a first switch module, a second switch module, a third switch module, a fourth switch module, a fifth switch module and an energy processing module, wherein the first switch module and the second switch module are respectively connected to the energy processing module, the energy processing module is also respectively connected to the third switch module and the fifth switch module, the second switch module is connected to the fifth switch module through the fourth switch module, the fifth switch module is connected to the power device, and the power device is also connected to the driving module; by controlling the third switch module and The on and off of the fifth switch module controls the on and off state of the power device. In the embodiment of the present application, a driving circuit is composed of multiple switching tubes, a Si-MOSFET, and an off-chip inductor. By changing the on and off state of the switching tube in the driving circuit, different circuit architectures are obtained, and then different working modes are realized. In this way, by providing a power device driving circuit structure that does not require the use of more off-chip passive components, has high integration, and can dynamically switch working modes, the structure can realize gate energy recovery in soft switching mode, theoretically with zero gate drive loss, and at the same time realize adjustable slew rate of gallium nitride in hard switching mode, so as to meet the actual needs of power devices for high efficiency, high reliability and multi-mode compatibility, save costs, and realize dual-mode switching control.

[0004] In a first aspect, some embodiments of the present application provide a drive circuit for a power device, the drive circuit comprising at least: a first switch module, a second switch module, a third switch module, a fourth switch module, a fifth switch module, and an energy processing module, wherein the first switch module and the second switch module are respectively connected to the energy processing module, the energy processing module is further respectively connected to the third switch module and the fifth switch module, the second switch module is connected to the fifth switch module via the fourth switch module, the fifth switch module is connected to a power device, and the power device is further connected to the drive module; By controlling the on and off of the third switch module and the fifth switch module, the on and off state of the power device is controlled.

[0005] Some embodiments of the present application form a driving circuit through multiple switching tubes, a Si-MOSFET, and an off-chip inductor. By changing the on-off state of the switching tube in the driving circuit, different circuit architectures are obtained, and then different operating modes are realized. In this way, by providing a power device driving circuit structure that does not require the use of more off-chip passive components, has high integration, and can dynamically switch operating modes, the structure can realize gate energy recovery in soft switching mode, theoretically with zero gate drive loss, and at the same time realize adjustable slew rate of gallium nitride in hard switching mode, so as to meet the actual requirements of power devices for high efficiency, high reliability and multi-mode compatibility, save costs, and realize dual-mode switching control.

[0006] Optionally, the first switch module, the second switch module, the third switch module, the fourth switch module, and the fifth switch module are respectively switch tubes. Some embodiments of the present application can implement mode switching by adopting multiple switch tubes, fully reuse the driver's internal inductors, capacitors, and switch networks in the circuit structure, and do not require the introduction of additional external negative voltage power supply or off-chip passive components, thereby significantly improving integration and reducing system size.

[0007] Optionally, the first end of the first switch tube is connected to the first power supply, the second end of the first switch tube is connected to the first end of the second switch tube, and the second end of the second switch tube is connected to the second power supply via the first capacitor; The second end of the first switch tube is connected to the first end of the energy processing module, the second end of the energy processing module is respectively connected to the second end of the third switch tube and the first end of the fifth switch tube, the first end of the third switch tube is connected to the second power supply, the second end of the fifth switch tube is connected to the gate of the power device, the second end of the second switch tube is connected to the second end of the fourth switch tube, and the first end of the fourth switch tube is connected to the second end of the fifth switch tube. Some embodiments of the present application provide a power device driving circuit structure that does not require the use of more off-chip passive components, has high integration, and can dynamically switch working modes. This structure can achieve gate energy recovery in soft switching mode, theoretically with zero gate drive loss, and at the same time achieve adjustable slew rate of gallium nitride in hard switching mode, so as to meet the actual requirements of power device power systems for high efficiency, high reliability, and multi-mode compatibility.

[0008] In a second aspect, some embodiments of the present application provide a method for driving a power device, which is applied to a driving circuit of a power device as described in any one of the first aspects, the method comprising: When the third switch module is turned on, determining a reverse boost-buck converter according to the first switch module, the second switch module and the energy processing module; generating a negative voltage for the power device according to the inverse step-up / step-down converter, so as to enable the power chip to operate in a conventional direct drive mode; When the fifth switch module is turned on, a resonant circuit is determined according to the first switch module, the second switch module, the third switch module, the fourth switch module and the energy processing module; According to the resonant circuit, the gate of the power device is controlled to charge and discharge, so that the power chip operates in a resonant direct drive mode.

[0009] Some embodiments of the present application provide a dual-mode power device drive circuit that uses a resonant drive mode to achieve effective gate energy recovery and significantly reduce drive energy consumption. This circuit is particularly suitable for high-frequency soft switching scenarios and reduces the number of switches and inductors used compared to traditional resonant drive solutions. Optionally, in the traditional direct drive mode, the method further includes: According to the size of the preset voltage value, the first switch module and the second switch module are switched to obtain a first control circuit and a second control circuit. The first control circuit includes a first switch module, a third switch module and the energy processing module; the second control circuit includes a second switch module, a third switch module and the energy processing module.

[0010] Optionally, the fourth switch module and the fifth switch module are used to drive the power device, and the charging rate of the power device is adjusted by adjusting the gate voltage of the fifth switch module.

[0011] In some embodiments of the present application, in CDD mode, dv / dt control and di / dt regulation of the GaN drain end are achieved by adjusting the equivalent impedance of the gate drive path.

[0012] Optionally, in the resonant direct drive mode, the method includes: When the first switch module, the fourth switch module, and the fifth switch module are turned on, the energy processing module is charged, the fourth switch module is turned off, and the gate of the power device is charged, so that the gate voltage of the power device changes from a negative voltage to 0; When the second switch module, the third switch module and the fifth switch module are turned on, the energy processing module discharges; When the third switch module and the fifth switch module are turned on, the gate voltage of the power device is controlled to be 0.

[0013] Optionally, in the resonant direct drive mode, the method includes: When the second switch module, the third switch module and the fifth switch module are turned on, charging the energy processing module; When the second switch module and the fifth switch module are turned on, a resonant circuit is formed according to the gate capacitance of the power device, the energy processing module of the fifth switch module, and the second switch module; and energy of the gate capacitance is transferred to the energy processing module. During the inductor discharge process, the first switch module, the fourth switch module, and the fifth switch module are turned on to generate a negative source driver power supply voltage, and transfer the energy of the energy processing module to the first power supply; When the fourth and fifth switching modules are turned on, the gate voltage of the power device is controlled to be the negative source driver power supply voltage. Some embodiments of the present application construct an internal resonant path in RDD mode to achieve gate charge and discharge recovery. By varying the inductor charging time, a negative voltage sufficient to shut off the gallium nitride is maintained.

[0014] In a third aspect, some embodiments of the present application provide a power chip, comprising at least one or more power devices, wherein the power device driving circuit described in any one of the first aspects is used to drive one power device, or a second driving circuit is used to drive the multiple power devices; the second driving circuit comprises at least seven switch modules and an energy processing module; The power chip further includes a bootstrap circuit, which is used to supply power to the driving circuit of the power device.

[0015] Optionally, the bootstrap circuit includes at least a bootstrap capacitor, which is used to power the third switch module and the fifth switch module; the bootstrap capacitor includes at least a main capacitor and a slave capacitor, the main capacitor is used to provide energy for turning on and off the third switch module and the fifth switch module, and the slave capacitor is used to reduce the ripple of the power supply of the third switch module. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the technical solutions of some embodiments of the present application, the following is a brief introduction to the drawings required for use in some embodiments of the present application. It should be understood that the following drawings only show certain embodiments of the present application and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other relevant drawings can be obtained based on these drawings without paying any creative work.

[0017] Figure 1 A schematic diagram of a driving circuit for a power device provided in an embodiment of the present application; Figure 2 A schematic diagram of a driving circuit in CDD mode provided in an embodiment of the present application; Figure 3 A schematic diagram of a driving circuit for turning on D-GaN in RDD mode provided in an embodiment of the present application; Figure 4 A schematic diagram of a circuit for shutting down D-GaN in RDD mode provided in an embodiment of the present application; Figure 5 A schematic diagram of the structure of the power chip provided in an embodiment of the present application; Figure 6 A schematic diagram of a bootstrap circuit provided in an embodiment of the present application; Figure 7 This is a schematic diagram of a bootstrap circuit in RDD working mode provided by an embodiment of the present application; Figure 8 This is a schematic diagram of a bootstrap circuit in CDD working mode provided by an embodiment of the present application; Figure 9 A schematic diagram of a circuit for driving two D-GaN devices provided in an embodiment of the present application. DETAILED DESCRIPTION

[0018] The technical solutions in some embodiments of the present application will be described below in conjunction with the drawings in some embodiments of the present application.

[0019] It should be noted that similar reference numerals and letters represent similar items in the following drawings. Therefore, once an item is defined in one drawing, it does not need to be further defined or explained in subsequent drawings. At the same time, in the description of this application, the terms "first", "second", etc. are only used to distinguish the description and should not be understood as indicating or implying relative importance.

[0020] In recent years, gallium nitride (GaN) devices have been widely used in high-frequency, high-efficiency power electronic systems due to their excellent switching performance, high breakdown voltage, and low on-resistance. Among the numerous GaN devices, depletion-mode (D-mode) GaN devices have gradually attracted attention from the research and industry communities due to their more stable electrical performance and greater voltage margin. However, since D-mode GaN devices are normally-on devices, a negative gate voltage must be provided during the driving process to achieve shutdown. This typically requires an additional negative voltage power supply and additional off-chip passive components, increasing system complexity and cost. Therefore, how can GaN devices be controlled while reducing costs? In view of this, some embodiments of the present application provide a power device driver circuit, which includes at least: a first switch module, a second switch module, a third switch module, a fourth switch module, a fifth switch module, and an energy processing module. The first switch module and the second switch module are respectively connected to the energy processing module, which is further connected to the third switch module and the fifth switch module, respectively. The second switch module is connected to the fifth switch module via the fourth switch module, and the fifth switch module is connected to the power device. The device is also connected to the driving module; by controlling the on and off of the third switch module and the fifth switch module, the on and off state of the power device is controlled. In the embodiment of the present application, a driving circuit is composed of multiple switching tubes, a Si-MOSFET, and an off-chip inductor. By changing the on and off state of the switching tube in the driving circuit, different circuit architectures are obtained, and then different working modes are realized. In this way, by providing a power device driving circuit structure that does not require the use of more off-chip passive components, has high integration, and can dynamically switch working modes, the structure can realize gate energy recovery in soft switching mode, theoretically with zero gate drive loss, and at the same time realize adjustable slew rate of gallium nitride in hard switching mode, so as to meet the actual requirements of power device power system for high efficiency, high reliability and multi-mode compatibility, save costs, and realize dual-mode switching control.

[0021] like Figure 1 As shown, the embodiment of the present application provides a driving circuit of a power device, the driving circuit at least includes: a first switch module S1, a second switch module S2, a third switch module S3, a fourth switch module S4, a fifth switch module S5 and an energy processing module L R , wherein the first switch module S1 and the second switch module S2 are respectively connected to the energy processing module LR Connected, energy processing module L R They are also connected to the third switch module S3 and the fifth switch module S5 respectively. The second switch module S2 is connected to the fifth switch module S5 through the fourth switch module S4. The fifth switch module S5 is connected to the power device, and the power device is also connected to the drive module. By controlling the on and off of the third switch module S3 and the fifth switch module S5, the on and off states of the power devices are controlled.

[0022] Among them, the energy processing module is an off-chip inductor, and the power device can be not only a depletion-mode gallium nitride, but also a power device such as SiC JFET that requires negative voltage shutdown and zero voltage or higher level turn-on; the driving module is a Si-MOS tube.

[0023] In the embodiment of the present application, the circuit structure fully reuses the internal inductance, capacitance and switching network of the driver, eliminating the need for additional external negative voltage power supply or off-chip passive components, significantly improving integration and reducing system size. The system can be switched to the appropriate drive mode (CDD or RDD) according to actual working conditions, making it suitable for GaN power systems where soft and hard switching coexist.

[0024] Some embodiments of the present application form a driving circuit through multiple switching tubes, a Si-MOSFET, and an off-chip inductor. By changing the on-off state of the switching tube in the driving circuit, different circuit architectures are obtained, and then different operating modes are realized. In this way, by providing a power device driving circuit structure that does not require the use of more off-chip passive components, has high integration, and can dynamically switch operating modes, the structure can realize gate energy recovery in soft switching mode, theoretically with zero gate drive loss, and at the same time realize adjustable slew rate of gallium nitride in hard switching mode, so as to meet the actual needs of power devices and power systems for high efficiency, high reliability and multi-mode compatibility.

[0025] Another embodiment of the present application further supplements the description of the driving circuit of the power device provided in the above embodiment.

[0026] Optionally, the first switch module, the second switch module, the third switch module, the fourth switch module and the fifth switch module are switch tubes respectively.

[0027] Some embodiments of the present application can achieve mode switching by adopting multiple switching tubes, fully reusing the internal inductance, capacitance and switching network of the driver in the circuit structure, without the need to introduce additional external negative voltage power supply or off-chip passive devices, significantly improving the integration and reducing the system size.

[0028] Optionally, the first end of the first switch tube is connected to the first power supply V DDThe second end of the first switch tube is connected to the first end of the second switch tube, and the second end of the second switch tube is connected to the second power supply through the first capacitor C1; The second end of the first switch tube is connected to the first end of the energy processing module, the second end of the energy processing module is respectively connected to the second end of the third switch tube and the first end of the fifth switch tube, and the first end of the third switch tube is connected to the second power supply V SS The second end of the fifth switch tube is connected to the gate of the power device, the second end of the second switch tube is connected to the second end of the fourth switch tube, and the first end of the fourth switch tube is connected to the second end of the fifth switch tube.

[0029] Some embodiments of the present application provide a D-GaN drive circuit structure that does not require the use of additional off-chip passive components, has high integration, and can dynamically switch operating modes. This structure can achieve gate energy recovery in soft-switching mode, with theoretically zero gate drive loss, while achieving adjustable slew rate of gallium nitride in hard-switching mode to meet the actual requirements of GaN power systems for high efficiency, high reliability, and multi-mode compatibility.

[0030] Illustratively, the driving circuit in the embodiment of the present application includes at least five switching tubes, a Si-MOSFET, and an off-chip inductor, and different circuit architectures are achieved by changing the conduction state of S3 and S5.

[0031] When the driver chip works in the conventional direct drive scheme (CDD), S3 is always on, and can form a circuit consisting of S1, S2 and inductor L R The conventional inverting step-up / step-down converter is used to generate the negative voltage required to turn off the GaN; S5 and S4 act as drivers to turn on and off the GaN.

[0032] When the driver chip works in the resonant direct driver (RDD) scheme, S5 is always on, S1~4 and inductor L R A resonant circuit is formed to meet the gate resonant charging and discharging of GaN. It should be noted that the various practicable methods in this embodiment can be implemented separately or in any combination without conflict, and this application does not limit them.

[0033] Another embodiment of the present application provides a method for driving a power device, which is used to execute the driving circuit of the power device provided in the above embodiment. The method includes: Step A1: When the third switch module is turned on, determine a reverse boost-buck converter according to the first switch module, the second switch module and the energy processing module; Step A2: Generate a negative voltage for the power device using the reverse boost-buck converter, so that the power chip operates in a conventional direct drive mode; Step A3: When the fifth switch module is turned on, a resonant circuit is determined according to the first switch module, the second switch module, the third switch module, the fourth switch module, and the energy processing module; Step A4: According to the resonant circuit, the gate of the power device is controlled to charge and discharge, so that the power chip operates in a resonant direct drive mode.

[0034] Some embodiments of the present application provide a dual-mode D-GaN drive circuit that achieves effective gate energy recovery through a resonant drive mode, significantly reducing drive energy consumption. The circuit is particularly suitable for high-frequency soft-switching operating scenarios and reduces the number of switches and inductors used compared to traditional resonant drive schemes.

[0035] Optionally, in the conventional direct drive mode, the method further comprises: According to the size of the voltage preset value, the first switch module S1 and the second switch module S2 are switched to obtain the first control circuit and the second control circuit. The first control circuit includes the first switch module S1, the third switch module S3 and the energy processing module L R The second control circuit includes a second switch module S2, a third switch module S3 and an energy processing module L R .

[0036] When the negative pressure generated is more negative than the preset value V1, both the first control circuit and the second control circuit do not work, and the voltage on the first capacitor is used to supply energy for the required negative pressure. Until the negative pressure on the first capacitor is higher than the preset value V1, the first control circuit starts to work and charges the energy processing module. The working time of the first control circuit is a preset fixed time. After the first control circuit finishes working, after a short delay, the second control circuit starts to work. In the second control circuit, the current of the energy processing module is drawn from the first capacitor, thereby generating a more negative voltage on the first capacitor. When the current of the energy processing module is close to zero, the second control circuit ends working. The first control circuit and the second control circuit will switch continuously until the negative pressure on the first capacitor is lower than the preset value V2, the first control circuit and the second control circuit stop working until the next time the voltage on the first capacitor is higher than the preset value V1, and the above operation is repeated. In order to ensure the stability of the negative voltage waveform, the preset value V2 is more negative than the preset value V1.

[0037] Optionally, the fourth switch module S4 and the fifth switch module S5 are used to drive the power device, and the charging rate of the power device is adjusted by adjusting the gate voltage of the fifth switch module.

[0038] In some embodiments of the present application, in CDD mode, dv / dt control and di / dt regulation of the GaN drain end are achieved by adjusting the equivalent impedance of the gate drive path.

[0039] like Figure 2 As shown, when the driver chip works in CDD mode, S3 is always on, and L R One end of the resistor is connected to ground, and S1, S2 and L form a traditional inverting step-up / step-down converter, which can generate the negative voltage required to turn off the depletion-mode GaN.

[0040] This inverting boost-buck converter operates in DCM to minimize losses. VSS and VNEG are the D-GaN turn-on and turn-off voltages, respectively. S4 and S5 form the final driver circuit for turning the GaN on and off. The gate-source voltage of S5 is adjustable, allowing it to function as an adjustable resistor.

[0041] By changing the on-resistance of S5, the charging speed of the GaN gate is changed, and the dv / dt control of D-GaN is adjusted.

[0042] Optionally, in the resonant direct drive mode, the method includes: When the first switch module, the fourth switch module, and the fifth switch module are turned on, the energy processing module is charged, the fourth switch module is turned off, and the gate of the power device is charged so that the gate voltage of the power device changes from a negative voltage to 0; When the second switch module, the third switch module and the fifth switch module are turned on, the energy processing module discharges; When the third switch module and the fifth switch module are turned on, the gate voltage of the power device is controlled to be 0.

[0043] like Figure 3 As shown in the figure, when the driver chip operates in RDD mode, S5 is always on. When the GaN needs to be turned on, S1, S4, and S5 are first turned on to precharge the inductor, allowing current to flow through the inductor and accelerating the charging of the GaN gate. This operating state is φ1. S4 is then turned off, allowing the inductor current to flow to the GaN gate. The GaN gate voltage gradually increases from negative to zero. This operating state is φ2. After the GaN gate capacitance is fully charged, a large amount of energy is stored in the inductor.

[0044] At this time, switches S2, S3, and S5 are turned on, allowing the inductor current to flow through V NEG ,L R , VSS path is used to discharge the energy on the inductor to generate a more negative negative source driver power supply voltage V NEG This working state is φ3. Finally, switches S3 and S5 are turned on, maintaining the gate of the GaN at 0.

[0045] It should be noted that there is an additional working state φopt during the process of turning on GaN ＊ When V NEG When the value is more negative than the set value, the state φopt ＊ is skipped during the GaN turn-on process. However, when V NEG When the value is more than the set value, the state φopt ＊ It is executed during the start-up process of GaN and is between the φ2 working state and the φ3 working state, charging more energy for the inductor so that a more negative V can be generated when the inductor is discharged. NEG .

[0046] Optionally, in the resonant direct drive mode, the method includes: When the second switch module, the third switch module and the fifth switch module are turned on, the energy processing module is charged; When the second switch module and the fifth switch module are turned on, a resonant circuit is formed according to the gate capacitance of the power device, the fifth switch module, the energy processing module, and the second switch module; and energy of the gate capacitance is transferred to the energy processing module. During the inductor discharge process, the first switch module, the fourth switch module, and the fifth switch module are turned on to generate a negative source driver power supply voltage and transfer the energy of the energy processing module to the first power supply; When the fourth switch module and the fifth switch module are turned on, the gate voltage of the control power device is the negative source driver power supply voltage V NEG .

[0047] Some embodiments of the present application construct an internal resonant path in RDD mode to achieve gate charge and discharge recovery. By varying the charging time of the inductor, a negative voltage capable of shutting off the GaN is maintained.

[0048] like Figure 4 As shown in the figure, when the power device (GaN) needs to be turned off, first S2, S3, and S5 are turned on to pre-charge the inductor. The working state is φ4. Then the switch S3 is turned off, and the GaN gate capacitor, S5, and inductor L are connected. R , S2 and capacitor V NEG Form a resonant circuit to transfer the energy of the gate capacitance to the inductor L R The working state is φ5.

[0049] Then it enters the inductor discharge state, S1, S4, S5 are turned on, and a more negative V NEG At the same time, energy is returned to the power supply VDD (first power supply), and the working state is φ6. Finally, S4 and S5 are turned on, and the gate of the power device is maintained at V NEG .

[0050] Some embodiments of the present application provide a power chip, which includes at least one or more power devices, and uses a driving circuit of the power device as described above to drive one power device, and uses a second driving circuit to drive multiple power devices; the second driving circuit includes at least seven switching modules and an energy processing module; the power chip also includes a bootstrap circuit, which is used to power the driving circuit of the power device.

[0051] Wherein, the second driving circuit is as follows Figure 9 As shown, it can be applied to drive two or more power devices. If there are two power devices, two additional switch tubes are added. The driving circuit includes switch tubes S1, S2, S3, S4.1, S5.1, S4.2, S5.2, and inductor L R , the second end of S1 is connected to the inductor L R Connected to the first end of S5.2, the second end of S5.2 is connected to the first end of S4.2, the second end of S4.2 is connected to the second end of S4.1, the second end of S4.1 is connected to the second end of S2, the second end of S1 is connected to the first end of S2, the second end of S3 is connected to the first end of S5.1, the first end of S3 is connected to ground, the second end of S5.1 is connected to the first power device, and the second end of S5.2 is connected to the second power device.

[0052] like Figure 5 As shown, the entire system, except for the external inductor and controlled gallium nitride, is integrated into a single chip. In addition to the power stage circuitry consisting of five switches and an inductor, the system also integrates a reference voltage module to generate a reference voltage, and a voltage modulation module to generate some internal voltages, reducing external voltage and signal requirements. The output voltage VNEG is divided by resistors and fed into a comparator to generate a signal. This signal determines whether to initiate state φopt in RDD mode or whether to activate the reverse step-up / step-down converter to maintain negative voltage in CDD mode. The chip also integrates the bootstrap circuits for S3 and S5.

[0053] Optionally, the bootstrap circuit includes at least a bootstrap capacitor, which is used to power the third switch module and the fifth switch module; the bootstrap capacitor includes at least a main capacitor and a slave capacitor, the main capacitor is used to provide energy for turning on and off the third switch module and the fifth switch module, and the slave capacitor is used to reduce the ripple of the power supply of the third switch module.

[0054] like Figure 6-Figure 8 As shown, in order to improve the utilization of the bootstrap capacitor, the bootstrap circuit of this design can share the same bootstrap capacitor to power switches S3 and S5 in two modes.

[0055] The bootstrap capacitor is split into two: CB1 and CB2. CB2 is the master capacitor, providing energy for turning switches S3 and S5 on and off. CB1 is the slave capacitor, primarily used to reduce ripple in the power supply to S3.

[0056] The power supply principle of the bootstrap circuit in different working modes is as follows Figure 7 and Figure 8 As shown in the figure, when the driver chip operates in RDD mode, since S5 is always open, the source terminals of S3 and S5 have the same potential, allowing CB1 and CB2 to be connected in parallel for simultaneous charging and discharging. When the GaN is turned on, the GaN gate is connected to VSS. At this time, the voltage nodes LS and VGATE of the bootstrap circuit are at VSS, allowing the bootstrap capacitor to be charged.

[0057] When the driver chip operates in CDD mode, switch S3 is normally open, connecting LS to VSS, so the top plate of capacitor CB1 can be directly connected to VDD. Charging capacitor CB2 requires an additional voltage zero-crossing detection module. This module detects when VGATE approaches zero from the negative voltage and outputs a high level to complete the charge replenishment of CB2.

[0058] Furthermore, the potential of the final driver stage of S5, powered by VPF, also changes. An external control signal, VX, enters the chip and is converted into a current signal, generating a reference voltage across resistor RSR. This voltage, after passing through a buffer, powers the final driver stage of S5. By varying the gate-source voltage when S5 is normally open, its on-resistance is altered. This allows for controlled pull-up current when the GaN is turned on, thereby controlling the GaN's dv / dt variation.

[0059] In an embodiment of the present application, a D-GaN drive circuit structure is provided that does not require the use of additional off-chip passive components, has a high degree of integration, and can dynamically switch operating modes. This structure can achieve gate energy recovery in soft-switching mode, with theoretically zero gate drive loss, while achieving adjustable slew rate of gallium nitride in hard-switching mode to meet the actual requirements of GaN power systems for high efficiency, high reliability, and multi-mode compatibility.

[0060] Regarding the device in this embodiment, the specific manner in which each module performs operations has been described in detail in the embodiment of the method and will not be elaborated here.

[0061] It should be noted that each implementable method in this embodiment can be implemented separately, or can be implemented in combination in any combination without conflict, and this application does not limit it.

[0062] The above are merely examples of the present application and are not intended to limit the scope of protection of the present application. For those skilled in the art, the present application may have various modifications and variations. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present application shall be included in the scope of protection of the present application. It should be noted that similar numbers and letters represent similar items in the following figures. Therefore, once an item is defined in one figure, it does not need to be further defined or explained in subsequent figures.

[0063] The above description is merely a specific embodiment of the present application, but the scope of protection of the present application is not limited thereto. Any changes or substitutions that can be easily conceived by a person skilled in the art within the technical scope disclosed in the present application should be included in the scope of protection of the present application. Therefore, the scope of protection of the present application should be based on the scope of protection of the claims.

[0064] It should be noted that, in this document, relational terms such as first and second, etc., are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply the existence of any such actual relationship or order between these entities or operations. Moreover, the terms "comprises," "comprising," or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article, or device comprising a series of elements includes not only those elements, but also other elements not explicitly listed, or elements inherent to such process, method, article, or device. In the absence of further limitations, an element defined by the phrase "comprising a ..." does not exclude the presence of other identical elements in the process, method, article, or device comprising the element.

Claims

1. A driving circuit for a power device, characterized in that: The driving circuit at least includes: a first switch module, a second switch module, a third switch module, a fourth switch module, a fifth switch module and an energy processing module, wherein the first switch module and the second switch module are respectively connected to the energy processing module, the energy processing module is also respectively connected to the third switch module and the fifth switch module, the second switch module is connected to the fifth switch module via the fourth switch module, the fifth switch module is connected to a power device, and the power device is also connected to the driving module; By controlling the on and off of the third switch module and the fifth switch module, the on and off state of the power device is controlled.

2. The driving circuit of a power device according to claim 1, wherein: The first switch module, the second switch module, the third switch module, the fourth switch module and the fifth switch module are switch tubes respectively.

3. The driving circuit of a power device according to claim 2, wherein: The first end of the first switch tube is connected to the first power supply, the second end of the first switch tube is connected to the first end of the second switch tube, and the second end of the second switch tube is connected to the second power supply via the first capacitor; The second end of the first switching tube is connected to the first end of the energy processing module, the second end of the energy processing module is respectively connected to the second end of the third switching tube and the first end of the fifth switching tube, the first end of the third switching tube is connected to the second power supply, the second end of the fifth switching tube is connected to the gate of the power device, the second end of the second switching tube is connected to the second end of the fourth switching tube, and the first end of the fourth switching tube is connected to the second end of the fifth switching tube.

4. A method for driving a power device, characterized in that: The method applied to the driving circuit of the power device according to any one of claims 1 to 3 comprises: When the third switch module is turned on, determining a reverse boost-buck converter according to the first switch module, the second switch module and the energy processing module; generating a negative voltage for the power device according to the inverse step-up / step-down converter, so as to enable the power chip to operate in a conventional direct drive mode; When the fifth switch module is turned on, a resonant circuit is determined according to the first switch module, the second switch module, the third switch module, the fourth switch module and the energy processing module; According to the resonant circuit, the gate of the power device is controlled to charge and discharge, so that the power chip operates in a resonant direct drive mode.

5. The driving method according to claim 4, wherein: In conventional direct drive mode, the method further includes: According to the size of the preset voltage value, the first switch module and the second switch module are switched to obtain a first control circuit and a second control circuit. The first control circuit includes a first switch module, a third switch module and the energy processing module; the second control circuit includes a second switch module, a third switch module and the energy processing module.

6. The driving method according to claim 5, wherein: The fourth switch module and the fifth switch module are used to drive the power device. The charging rate of the power device is adjusted by adjusting the gate voltage of the fifth switch module.

7. The driving method according to claim 5, characterized in that: In resonant direct drive mode, the method includes: When the first switch module, the fourth switch module, and the fifth switch module are turned on, the energy processing module is charged, the fourth switch module is turned off, and the gate of the power device is charged, so that the gate voltage of the power device changes from a negative voltage to 0; When the second switch module, the third switch module and the fifth switch module are turned on, the energy processing module discharges; When the third switch module and the fifth switch module are turned on, the gate voltage of the power device is controlled to be 0.

8. The driving method according to claim 5, wherein: In resonant direct drive mode, the method includes: When the second switch module, the third switch module and the fifth switch module are turned on, charging the energy processing module; When the second switch module and the fifth switch module are turned on, a resonant circuit is formed according to the gate capacitance of the power device, the fifth switch module, the energy processing module, and the second switch module; and energy of the gate capacitance is transferred to the energy processing module. During the inductor discharge process, the first switch module, the fourth switch module, and the fifth switch module are turned on to generate a negative source driver power supply voltage, and transfer the energy of the energy processing module to the first power supply; When the fourth switch module and the fifth switch module are turned on, the gate voltage of the power device is controlled to be the negative source driver power supply voltage.

9. A power chip, characterized in that: The power chip includes at least one or more power devices, a power device driving circuit according to any one of claims 1 to 3 is used to drive one power device, and a second driving circuit is used to drive the multiple power devices; the second driving circuit includes at least seven switch modules and an energy processing module; The power chip further includes a bootstrap circuit, which is used to supply power to the driving circuit of the power device.

10. The power chip according to claim 9, characterized in that: The bootstrap circuit includes at least a bootstrap capacitor, which is used to power the third switch module and the fifth switch module; the bootstrap capacitor includes at least a main capacitor and a slave capacitor, the main capacitor is used to provide energy for turning on and off the third switch module and the fifth switch module, and the slave capacitor is used to reduce the ripple of the power supply of the third switch module.

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