A driving circuit, control method and power chip of a power device

Abstract

The embodiment of the application provides a kind of power device driving circuit, control method and power chip, the driving circuit at least includes: first switch module, second switch module, third switch module, fourth switch module, fifth switch module and energy processing module, wherein, first switch module and second switch module are connected with energy processing module respectively, energy processing module is also connected with third switch module and fifth switch module respectively, second switch module is connected with fifth switch module by fourth switch module, fifth switch module is connected with power device, and power device is also connected with driving module;The on-off state of power device is controlled by controlling the on-off of third switch module and fifth switch module, provides a kind of power device driving circuit structure without using more off-chip passive device, high integration, dynamically switchable mode, saves cost, also realizes double mode switching control.

Description

Technical Field

[0001] This application relates to the field of electronic circuit technology, and more specifically, to a driving circuit, control method, and power chip for a power device. Background Technology

[0002] 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 many GaN devices, depletion-mode (D-mode) GaN devices have gradually attracted attention from research and industry due to their more stable electrical performance and larger voltage margin. However, since D-mode GaN devices are normally-on devices, a negative gate voltage is required to turn them off during driving. This typically requires an additional negative voltage power supply and extra off-chip passive components, increasing system complexity and cost. Therefore, how to achieve control of gallium nitride (GaN) devices while reducing costs is an urgent problem to be solved. Summary of the Invention

[0003] The purpose of some embodiments of this application is to provide a driving circuit, control method, and power chip for a power device. Through the technical solutions of the embodiments of this application, a driving circuit for a power device is provided, which includes at least: a first switching module, a second switching module, a third switching module, a fourth switching module, a fifth switching module, and an energy processing module. The first switching module and the second switching module are respectively connected to the energy processing module, and the energy processing module is also respectively connected to the third switching module and the fifth switching module. The second switching module is connected to the fifth switching module through the fourth switching module. The fifth switching module is connected to the power device, and the power device is also connected to the driving module. By controlling the third switching module and... The on / off state of the power device is controlled by the switching module of the fifth switching module. In this embodiment, the driving circuit is composed of multiple switching transistors, a Si-MOSFET, and an off-chip inductor. By changing the on / off state of the switching transistors in the driving circuit, different circuit architectures are obtained, thereby realizing different operating modes. In this way, a power device driving circuit structure with high integration and dynamic switching mode is provided without the need for more off-chip passive components. This structure can realize gate energy recovery in soft switching mode, theoretically with zero gate drive loss, and at the same time realize adjustable gallium nitride slew rate in hard switching mode to meet the actual needs of high efficiency, high reliability and multi-mode compatibility in power devices, save costs, and realize dual-mode switching control.

[0004] In a first aspect, some embodiments of this application provide a driving circuit for a power device. The driving circuit includes at least: a first switching module, a second switching module, a third switching module, a fourth switching module, a fifth switching module, and an energy processing module. The first switching module and the second switching module are respectively connected to the energy processing module. The energy processing module is also respectively connected to the third switching module and the fifth switching module. The second switching module is connected to the fifth switching module through the fourth switching module. The fifth switching module is connected to the power device. The power device is also connected to the driving module.

[0005] The on / off state of the power device is controlled by controlling the on / off states of the third and fifth switch modules.

[0006] Some embodiments of this application use multiple switching transistors, a Si-MOSFET, and an off-chip inductor to form a driving circuit. By changing the on / off state of the switching transistors in the driving circuit, different circuit architectures are obtained, thereby achieving different operating modes. In this way, a power device driving circuit structure that does not require more off-chip passive components, has high integration, and can dynamically switch operating modes is provided. This structure can achieve gate energy recovery in soft-switching mode, theoretically with zero gate drive loss, while achieving adjustable gallium nitride slew rate in hard-switching mode. This meets the actual requirements of high efficiency, high reliability, and multi-mode compatibility in power devices, saves costs, and also realizes dual-mode switching control.

[0007] Optionally, the first switch module, the second switch module, the third switch module, the fourth switch module, and the fifth switch module are all switching transistors. Some embodiments of this application can achieve mode switching by using multiple switching transistors, fully reusing the inductors, capacitors, and switching networks inside the driver in the circuit structure, without the need to introduce additional external negative voltage power supply or off-chip passive components, significantly improving integration and reducing system size.

[0008] Optionally, the first terminal of the first switching transistor is connected to the first power supply, the second terminal of the first switching transistor is connected to the first terminal of the second switching transistor, and the second terminal of the second switching transistor is connected to the second power supply through the first capacitor.

[0009] The second terminal of the first switching transistor is connected to the first terminal of the energy processing module. The second terminal of the energy processing module is connected to the second terminal of the third switching transistor and the first terminal of the fifth switching transistor. The first terminal of the third switching transistor is connected to the second power supply. The second terminal of the fifth switching transistor is connected to the gate of the power device. The second terminal of the second switching transistor is connected to the second terminal of the fourth switching transistor. The first terminal of the fourth switching transistor is connected to the second terminal of the fifth switching transistor. Some embodiments of this application provide a power device drive circuit structure that does not require 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, theoretically with zero gate drive loss, while achieving adjustable gallium nitride slew rate in hard-switching mode to meet the actual requirements of high efficiency, high reliability, and multi-mode compatibility in power device power systems.

[0010] Secondly, some embodiments of this application provide a driving method for a power device, applied to a driving circuit of the power device as described in any of the first aspects, the method comprising:

[0011] When the third switch module is turned on, a reverse boost-buck converter is determined based on the first switch module, the second switch module, and the energy processing module.

[0012] The reverse boost-buck converter generates a negative voltage for the power device, enabling the power chip to operate in a conventional direct drive mode.

[0013] When the fifth switch module is turned on, a resonant circuit is determined based on the first switch module, the second switch module, the third switch module, the fourth switch module, and the energy processing module.

[0014] According to the resonant circuit, the gate of the power device is controlled to charge and discharge, so that the power chip operates in the resonant direct drive mode.

[0015] Some embodiments of this application provide a dual-mode power device drive circuit that achieves effective gate energy recovery through resonant drive mode, significantly reducing drive energy consumption. This is particularly suitable for high-frequency soft-switching scenarios, reducing the number of switches and inductors compared to traditional resonant drive schemes. Optionally, in the traditional direct drive mode, the method further includes:

[0016] Based on 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.

[0017] 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.

[0018] In some embodiments of this application, dv / dt control and di / dt adjustment of the GaN drain terminal are achieved by adjusting the equivalent impedance of the gate drive path in CDD mode.

[0019] Optionally, in the resonant direct drive mode, the method includes:

[0020] 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 negative to 0.

[0021] When the second switch module, the third switch module, and the fifth switch module are turned on, the energy processing module discharges;

[0022] 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.

[0023] Optionally, in the resonant direct drive mode, the method includes:

[0024] When the second switch module, the third switch module, and the fifth switch module are turned on, the energy processing module is charged;

[0025] When the second switching module and the fifth switching module are turned on, a resonant circuit is formed by the gate capacitance of the power device, the energy processing module of the fifth switching module, and the second switching module; the energy of the gate capacitance is transferred to the energy processing module.

[0026] During the inductor discharge process, the first switch module, the fourth switch module, and the fifth switch module are turned on, generating the negative source driver power supply voltage and transferring the energy of the energy processing module to the first power supply.

[0027] When the fourth and fifth switching modules are turned on, the gate voltage of the power device is controlled to be the power supply voltage of the negative source driver. Some embodiments of this application construct an internal resonant path in RDD mode to achieve gate charge / discharge recovery. By changing the inductor's charging time, a negative voltage capable of turning off gallium nitride is maintained.

[0028] Thirdly, some embodiments of this application provide a power chip, which includes at least one or more power devices. A driving circuit for the power devices as described in any of the first aspects is used to drive one power device, or a second driving circuit is used to drive the plurality of power devices. The second driving circuit includes at least seven switching modules and an energy processing module.

[0029] The power chip also includes a bootstrap circuit, which is used to supply power to the drive circuit of the power device.

[0030] Optionally, the bootstrap circuit includes at least a bootstrap capacitor for supplying power to the third and fifth switching modules; the bootstrap capacitor includes at least a main capacitor and a slave capacitor, the main capacitor for providing energy for the switching on and off of the third and fifth switching modules, and the slave capacitor for reducing the ripple of the power supply to the third switching module. Attached Figure Description

[0031] To more clearly illustrate the technical solutions of some embodiments of this application, the accompanying drawings used in some embodiments of this application will be briefly described below. It should be understood that the following drawings only show some embodiments of this application and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0032] Figure 1 A schematic diagram of a driving circuit for a power device provided in an embodiment of this application;

[0033] Figure 2 A schematic diagram of the driving circuit in CDD mode provided in an embodiment of this application;

[0034] Figure 3 A schematic diagram of the driving circuit for opening D-GaN in RDD mode provided for an embodiment of this application;

[0035] Figure 4 A schematic diagram of a circuit for turning off D-GaN in RDD mode, provided for an embodiment of this application;

[0036] Figure 5 This is a schematic diagram of the power chip structure provided in an embodiment of this application;

[0037] Figure 6 A schematic diagram of a bootstrap circuit provided in an embodiment of this application;

[0038] Figure 7 This is a schematic diagram of a bootstrap circuit operating in RDD mode, provided in an embodiment of this application.

[0039] Figure 8 A schematic diagram of a bootstrap circuit in CDD operating mode provided in an embodiment of this application;

[0040] Figure 9 This is a schematic diagram of a circuit for driving two D-GaN transistors, provided in an embodiment of this application. Detailed Implementation

[0041] The technical solutions of some embodiments of this application will now be described with reference to the accompanying drawings.

[0042] It should be noted that similar reference numerals and letters in the following figures indicate similar items; therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures. Furthermore, in the description of this application, terms such as "first," "second," etc., are used only to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0043] 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 many GaN devices, depletion-mode (D-mode) GaN devices have gradually attracted the attention of research and industry due to their more stable electrical performance and larger voltage margin. However, since D-mode GaN devices are normally open devices, a negative gate voltage is required during the driving process to achieve turn-off. This usually requires an additional negative voltage power supply and additional off-chip passive components, increasing system complexity and cost. Therefore, how to achieve control of gallium nitride (GaN) devices while reducing costs is a key challenge. In view of this, some embodiments of this application provide a driving circuit for a power device. This driving circuit includes at least: a first switching module, a second switching module, a third switching module, a fourth switching module, a fifth switching module, and an energy processing module. The first and second switching modules are respectively connected to the energy processing module, which is also connected to the third and fifth switching modules. The second switching module is connected to the fifth switching module through the fourth switching module. The fifth switching module is connected to the power device. The device is also connected to the drive module; by controlling the on / off state of the third and fifth switch modules, the on / off state of the power device is controlled. In this embodiment, the drive circuit is composed of multiple switching transistors, a Si-MOSFET, and an off-chip inductor. By changing the on / off state of the switching transistors in the drive circuit, different circuit architectures are obtained, thereby realizing different operating modes. In this way, a power device drive circuit structure that does not require more off-chip passive components, has high integration, and can dynamically switch operating modes is provided. This structure can realize gate energy recovery in soft switching mode, theoretically with zero gate drive loss, and at the same time, it can realize adjustable gallium nitride slew rate in hard switching mode to meet the actual needs of high efficiency, high reliability and multi-mode compatibility in power device power systems, save costs, and also realize dual-mode switching control.

[0044] like Figure 1 As shown, embodiments of this application provide a driving circuit for a power device. The driving circuit includes at least: a first switching module S1, a second switching module S2, a third switching module S3, a fourth switching module S4, a fifth switching module S5, and an energy processing module L. R The first switch module S1 and the second switch module S2 are respectively connected to the energy processing module L. R Connected, energy processing module L R It is 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. The power device is also connected to the drive module.

[0045] The on / off state of the power device is controlled by controlling the on / off state of the third switch module S3 and the fifth switch module S5.

[0046] The energy processing module is an off-chip inductor, and the power device can be not only depletion-mode gallium nitride, but also power devices such as SiC JFET that require negative voltage turn-off and zero voltage or higher level turn-on; the driving module is a Si-MOS transistor.

[0047] In this embodiment, the internal inductors, capacitors and switching networks of the driver are fully reused in the circuit structure, without the need to introduce external negative voltage power supply or off-chip passive components, which significantly improves the integration and reduces the system size. It can switch to the appropriate driving mode (CDD or RDD) according to the actual working conditions, and is suitable for GaN power systems where soft and hard switching coexist.

[0048] Some embodiments of this application use multiple switching transistors, a Si-MOSFET, and an off-chip inductor to form a driving circuit. By changing the on / off state of the switching transistors in the driving circuit, different circuit architectures are obtained, thereby achieving different operating modes. In this way, a power device driving circuit structure that does not require more off-chip passive components, has high integration, and can dynamically switch operating modes is provided. This structure can achieve gate energy recovery in soft-switching mode, theoretically with zero gate drive loss, while achieving adjustable gallium nitride slew rate in hard-switching mode, thus meeting the actual requirements of high efficiency, high reliability, and multi-mode compatibility in power device power systems.

[0049] Another embodiment of this application further illustrates the driving circuit of the power device provided in the above embodiments.

[0050] Optionally, the first switch module, the second switch module, the third switch module, the fourth switch module, and the fifth switch module are all switching transistors.

[0051] Some embodiments of this application can achieve mode switching by using multiple switching transistors. The circuit structure fully reuses the inductors, capacitors and switching networks inside the driver, without the need to introduce external negative voltage power supply or off-chip passive components, which significantly improves the integration and reduces the system size.

[0052] Optionally, the first terminal of the first switching transistor is connected to the first power supply V. DD The second terminal of the first switching transistor is connected to the first terminal of the second switching transistor, and the second terminal of the second switching transistor is connected to the second power supply through the first capacitor C1.

[0053] The second terminal of the first switching transistor is connected to the first terminal of the energy processing module. The second terminal of the energy processing module is connected to the second terminal of the third switching transistor and the first terminal of the fifth switching transistor. The first terminal of the third switching transistor is connected to the second power supply V.SS The second terminal of the fifth switch is connected to the gate of the power device, the second terminal of the second switch is connected to the second terminal of the fourth switch, and the first terminal of the fourth switch is connected to the second terminal of the fifth switch.

[0054] Some embodiments of this application provide a D-GaN driving circuit structure that does not require the use of more off-chip passive devices, has high integration, and can dynamically switch operating modes. This structure can achieve gate energy recovery in soft-switching mode, theoretically with zero gate drive loss, while achieving adjustable gallium nitride slew rate in hard-switching mode, so as to meet the actual needs of GaN power systems for high efficiency, high reliability and multi-mode compatibility.

[0055] For example, the driving circuit in the embodiments of this application includes at least 5 switching transistors, one Si-MOSFET, and one off-chip inductor, and different circuit architectures are achieved by changing the conduction states of S3 and S5.

[0056] When the driver chip operates in the Conventional Direct Driver (CDD) scheme, S3 is always on, and can form a configuration consisting of S1, S2 and inductor L. R A conventional inverting boost-buck converter is used to generate the negative voltage required to turn off GaN; S5 and S4 act as drivers to turn GaN on and off.

[0057] When the driver chip operates in the resonant direct driver (RDD) scheme, S5 is always on, and S1~4 and inductor L... R This forms a resonant circuit, satisfying the gate resonant charging and discharging of GaN. It should be noted that the various implementable methods in this embodiment can be implemented individually or in any combination without conflict; this application does not impose any limitations on this.

[0058] Another embodiment of this application provides a driving method for a power device, used to execute the driving circuit of the power device provided in the above embodiment, the method comprising:

[0059] Step A1: With the third switch module turned on, determine the reverse boost-buck converter based on the first switch module, the second switch module, and the energy processing module;

[0060] Step A2: Based on the inverting boost-buck converter, a negative voltage is generated for the power device so that the power chip operates in the traditional direct drive mode;

[0061] Step A3: With the fifth switch module turned on, determine the resonant circuit based on the first switch module, the second switch module, the third switch module, the fourth switch module, and the energy processing module;

[0062] Step A4: According to the resonant circuit, control the gate of the power device to charge and discharge so that the power chip operates in the resonant direct drive mode.

[0063] The dual-mode D-GaN driving circuit provided in some embodiments of this application achieves effective gate energy recovery through resonant driving mode, significantly reducing driving energy consumption. It is especially suitable for high-frequency soft-switching scenarios and reduces the number of switches and inductors used compared to traditional resonant driving schemes.

[0064] Optionally, in the traditional direct drive mode, the method further includes:

[0065] Based on the preset voltage value, the first switching module S1 and the second switching module S2 are switched to obtain a first control circuit and a second control circuit. The first control circuit includes the first switching module S1, the third switching module S3, and the energy processing module L. R The second control circuit includes a second switching module S2, a third switching module S3, and an energy processing module L. R .

[0066] When the generated negative voltage is more negative than the preset value V1, both the first and second control circuits are inactive, using the voltage on the first capacitor to power the required negative voltage. The first control circuit starts operating and charging the energy processing module only when the negative voltage on the first capacitor exceeds the preset value V1. The first control circuit operates for a preset fixed time. After the first control circuit finishes operating, the second control circuit starts operating after a short delay. In the second control circuit, the current from the energy processing module is drawn from the first capacitor, generating a more negative voltage on it. When the current in the energy processing module approaches zero, the second control circuit stops operating. The first and second control circuits continuously switch until the negative voltage on the first capacitor is lower than the preset value V2, at which point both circuits stop operating. This process repeats until the voltage on the first capacitor is higher than the preset value V1 again. To ensure the stability of the negative voltage waveform, the preset value V2 is more negative than the preset value V1.

[0067] 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.

[0068] In some embodiments of this application, dv / dt control and di / dt adjustment of the GaN drain terminal are achieved by adjusting the equivalent impedance of the gate drive path in CDD mode.

[0069] like Figure 2As shown, when the driver chip is operating in CDD mode, S3 is always on, which will turn L... R One end is connected to ground. S1, S2 and L constitute a conventional inverting boost-buck converter, which can generate the negative voltage required to turn off depletion-type gallium nitride.

[0070] This inverting boost-buck converter operates in DCM to reduce losses. VSS and VNEG are the turn-on and turn-off voltages for the D-GaN, respectively. S4 and S5 constitute the final stage drive circuit for turning on and off the gallium nitride. The gate-source voltage of S5 is adjustable, allowing S5 to function as an adjustable resistor.

[0071] By changing the on-resistance of S5, the charging speed of the gallium nitride gate is altered, thereby achieving adjustment of the dv / dt control of D-GaN.

[0072] Optionally, in the resonant direct drive mode, the method includes:

[0073] With the first, fourth, and fifth switch modules on, the energy processing module is charged; with the fourth switch module off, the gate of the power device is charged so that the gate voltage of the power device changes from negative to 0.

[0074] With the second, third, and fifth switch modules turned on, the energy processing module discharges.

[0075] With the third and fifth switching modules turned on, the gate voltage of the control power device is 0.

[0076] like Figure 3 As shown, when the driver chip is operating in RDD mode, S5 is always on. When it is necessary to turn on the gallium nitride (GaN), S1, S4, and S5 are first turned on to pre-charge the inductor, allowing current to flow into the inductor and accelerating the subsequent charging speed of the GaN gate. This operating state is φ1. Then, S4 is turned off, allowing the current from the inductor to flow to the GaN gate, and the GaN gate voltage gradually rises from negative to 0. This operating state is φ2. After the GaN gate capacitor is fully charged, a significant amount of energy is stored in the inductor.

[0077] At this time, switches S2, S3, and S5 are turned on, allowing the current in the inductor to flow through V. NEG ,L R The VSS path discharges, generating a more negative source driver power supply voltage V from the energy on the inductor. NEG The operating state is φ3. Finally, switches S3 and S5 are turned on, maintaining the gallium nitride gate at 0.

[0078] It is important to note that there is an additional working state φopt during the gallium nitride activation process. When V NEG When the value is more negative than the set value, the state φopt It is skipped during the gallium nitride (GaN) turn-on process. However, when V... NEG When the value is corrected compared to the set value, the state φopt This is executed during the gallium nitride (GaN) turn-on process, and occurs between the φ2 and φ3 operating states, to charge the inductor with more energy, allowing it to generate a more negative V during discharge. NEG .

[0079] Optionally, in the resonant direct drive mode, the method includes:

[0080] With the second, third, and fifth switch modules turned on, the energy processing module is charged.

[0081] When the second and fifth switching modules are turned on, a resonant circuit is formed by the gate capacitance of the power device, the fifth switching module, the energy processing module, and the second switching module; the energy of the gate capacitance is transferred to the energy processing module.

[0082] During the inductor discharge process, the first switch module, the fourth switch module and the fifth switch module are turned on, generating the negative source driver power supply voltage and transferring the energy of the energy processing module to the first power supply.

[0083] With the fourth and fifth switching modules turned on, the gate voltage of the control power device is equal to the negative source driver power supply voltage V. NEG .

[0084] Some embodiments of this application construct an internal resonant path in RDD mode to achieve gate charge / discharge recovery. By changing the inductor's charging time, a negative voltage capable of turning off gallium nitride is maintained.

[0085] like Figure 4 As shown, when the power device (gallium nitride) needs to be turned off, S2, S3, and S5 are first turned on to precharge the inductor; this operating state is φ4. Then, switch S3 is turned off, and the power is supplied through the gallium nitride gate capacitor, S5, and inductor L. R S2 and capacitor V NEG This forms a resonant circuit, transferring the energy from the gate capacitance to the inductor L. R The working state is φ5.

[0086] Then it enters the inductor discharge state, S1, S4, and S5 are turned on, generating a more negative V. NEG Simultaneously, energy is returned to the power supply VDD (first power supply), and this operating state is φ6. Finally, S4 and S5 are turned on, and the gate of the power device is maintained at V. NEG .

[0087] Some embodiments of this application provide a power chip, which includes at least one or more power devices. A driving circuit for the power devices as described above is used to drive one power device, and a second driving circuit is used 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 for supplying power to the driving circuit of the power devices.

[0088] Among them, the second driving circuit is as follows Figure 9 As shown, this circuit can be applied to drive two or more power devices. If there are two power devices, two additional switching transistors are added. The drive circuit includes switching transistors S1, S2, S3, S4.1, S5.1, S4.2, and S5.2, and an inductor L. R The second terminal of S1 is connected to inductor L R The first terminal of S5.2 is connected to the first terminal of S4.2, the second terminal of S4.2 is connected to the second terminal of S4.1, the second terminal of S4.1 is connected to the second terminal of S2, the second terminal of S1 is connected to the first terminal of S2, the second terminal of S3 is connected to the first terminal of S5.1, the first terminal of S3 is connected to ground, the second terminal of S5.1 is connected to the first power device, and the second terminal of S5.2 is connected to the second power device.

[0089] like Figure 5 As shown, the entire system, except for the off-chip inductor and the controlled gallium nitride, can be integrated onto a single chip. Besides the power stage circuit consisting of five switches and an inductor, the system 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, after being divided by resistors, enters a comparator to generate a signal. This signal determines whether to perform state φopt in RDD mode and whether to operate the inverting boost-buck converter to maintain a negative voltage in CDD mode. The chip internally integrates bootstrap circuits S3 and S5.

[0090] Optionally, the bootstrap circuit includes at least a bootstrap capacitor for powering the third and fifth switching modules; the bootstrap capacitor includes at least a main capacitor and a slave capacitor, the main capacitor for providing energy for the switching on and off of the third and fifth switching modules, and the slave capacitor for reducing the ripple of the power supply to the third switching module.

[0091] like Figures 6-8 As shown, in order to improve the utilization rate of the bootstrap capacitor, the bootstrap circuit of this design can share the same bootstrap capacitor to power switches S3 and S5 in both modes.

[0092] The bootstrap capacitor is split into two: CB1 and CB2. CB2 is the main capacitor, providing energy for the opening and closing of switches S3 and S5. CB1 is the slave capacitor, primarily used to reduce the ripple in the power supply to S3.

[0093] The power supply principle of the bootstrap circuit in different operating modes is as follows: Figure 7 and Figure 8 As shown, when the driver chip operates in RDD mode, since S5 is normally open, the source potentials of S3 and S5 are the same, allowing CB1 and CB2 to be connected in parallel for simultaneous charging and discharging. When gallium nitride (GaN) is turned on, its gate is connected to VSS. At this time, the voltage nodes LS and VGATE of the bootstrap circuit are VSS, allowing the bootstrap capacitor to be charged.

[0094] When the driver chip operates in CDD mode, since switch S3 is normally open, LS is connected to VSS, so the upper plate of capacitor CB1 can be directly connected to VDD. Charging capacitor CB2 requires an additional zero-crossing voltage detection module, which detects when VGATE approaches zero from a negative voltage level and outputs a high level to replenish the charge of CB2.

[0095] Furthermore, the potential of the final stage of the S5 driver is also altered; it is powered by VPF. An external control signal VX enters the chip, is converted into a current signal, and generates a reference voltage across resistor RSR. This voltage, after passing through a buffer, powers the final stage of the S5 driver. By changing the gate-source voltage of S5 when it is normally open, its on-resistance is altered, thus controlling the pull-up current when GaN is turned on, thereby controlling the dv / dt change of GaN.

[0096] This application provides a D-GaN driving circuit structure that does not require additional off-chip passive devices, has high integration, and can dynamically switch operating modes. This structure can achieve gate energy recovery in soft-switching mode, theoretically with zero gate drive loss, while achieving adjustable gallium nitride slew rate in hard-switching mode, so as to meet the actual requirements of GaN power systems for high efficiency, high reliability and multi-mode compatibility.

[0097] Regarding the apparatus in this embodiment, the specific manner in which each module performs its operations has been described in detail in the embodiments related to the method, and will not be elaborated upon here.

[0098] It should be noted that each of the implementable methods in this embodiment can be implemented individually or in any combination without conflict. This application does not limit this.

[0099] The above are merely embodiments of this application and are not intended to limit the scope of protection of this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the scope of protection of this application. It should be noted that similar reference numerals and letters in the following figures indicate similar items; therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0100] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

[0101] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

Claims

1. A driving circuit of a power device, characterized by comprising: The driving circuit 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, wherein the first end of the first switch transistor is connected to the first power supply, the second end of the first switch transistor is connected to the first end of the second switch transistor, and the second end of the second switch transistor is connected to the second power supply through the first capacitor. The second terminal of the first switching transistor is connected to the first terminal of the energy processing module. The second terminal of the energy processing module is connected to the second terminal of the third switching transistor and the first terminal of the fifth switching transistor. The first terminal of the third switching transistor is connected to the second power supply. The second terminal of the fifth switching transistor is connected to the gate of the power device. The second terminal of the second switching transistor is connected to the second terminal of the fourth switching transistor. The first terminal of the fourth switching transistor is connected to the second terminal of the fifth switching transistor. The on / off state of the power device is controlled by controlling the on / off state of the third switch module and the fifth switch module; When the third switch module is turned on, a reverse boost-buck converter is determined based on the first switch module, the second switch module, and the energy processing module. The reverse boost-buck converter generates a negative voltage for the power device, enabling the power chip to operate in a conventional direct drive mode. When the fifth switch module is turned on, a resonant circuit is determined based on 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 the resonant direct drive mode.

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 all switching transistors.

3. A method of driving a power device, characterized by, The method, applied to a drive circuit for a power device as described in any one of claims 1-2, comprises: When the third switch module is turned on, a reverse boost-buck converter is determined based on the first switch module, the second switch module, and the energy processing module. The reverse boost-buck converter generates a negative voltage for the power device, enabling the power chip to operate in a conventional direct drive mode. When the fifth switch module is turned on, a resonant circuit is determined based on 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 the resonant direct drive mode.

4. The driving method according to claim 3, wherein In the traditional direct-drive mode, the method further includes: Based on 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.

5. The driving method according to claim 4, wherein The fourth and fifth switching modules are used to drive the power device. The charging rate of the power device is adjusted by adjusting the gate voltage of the fifth switching module.

6. The driving method according to claim 4, wherein 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 negative 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.

7. The driving method according to claim 4, wherein 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 switching module and the fifth switching module are turned on, a resonant circuit is formed by the gate capacitance of the power device, the fifth switching module, the energy processing module, and the second switching module; the 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, generating the negative source driver power supply voltage and transferring 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 power supply voltage of the negative source driver.

8. A power chip, characterized by The power chip includes one or two power devices. If the power chip includes one power device, the power device is driven by the driving circuit of the power device as described in any one of claims 1-2. If the power chip includes two power devices, a second driving circuit is used to drive the two power devices; the second driving circuit is obtained by adding a switching module to the driving circuit of the power device as described in any one of claims 1-2; The second driving circuit includes switching transistors S1, S2, S3, S4.1, S5.1, S4.2, and S5.2, and an inductor L. R The first terminal of S1 is connected to VDD, and the second terminal of S1 is connected to the inductor L. R The first end is connected, inductor L R The second end of S1 is connected to the second end of S3, the first end of S5.2, and the first end of S5.1, respectively; the second end of S1 is connected to the first end of S2; the first end of S3 is connected to ground. The second terminal of S5.1 is connected to the first terminal of S4.1 and the gate of the first power device; the second terminal of S4.1 is connected to the second terminal of S2; the second terminal of S2 is connected to ground through capacitor C1. The second terminal of S5.2 is connected to the gate of the second power device and the first terminal of S4.2, respectively, and the second terminal of S4.2 is connected to the second terminal of S4.1; The power chip also includes a bootstrap circuit, which is used to supply power to the drive circuit of the power device.

9. The power chip according to claim 8, characterized in that, In the case where the power chip includes a power device and the power device is driven by the driving circuit of the power device, the bootstrap circuit includes at least a bootstrap capacitor for supplying power to the third switching module and the fifth switching module; the bootstrap capacitor includes at least a main capacitor and a slave capacitor, the main capacitor for providing energy for the switching on and off of the third switching module and the fifth switching module, and the slave capacitor for reducing the ripple of the power supply to the third switching module.

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