A driving power supply circuit based on gallium nitride power chip

Abstract

The present invention discloses a driving power supply circuit based on a gallium nitride power chip, comprising an EMI filter and rectifier circuit module, an APFC active power factor correction circuit module, a PWM control circuit module, a power switch gallium nitride chip U4, a switch transformer T1A, and an output rectifier filter circuit module, which are sequentially connected in the direction from AC input to DC output, wherein the APFC active power factor correction circuit module realizes power factor correction by connecting to a PFC control circuit module, and a voltage detection feedback loop for output voltage detection feedback is provided between the output rectifier filter circuit module and the PWM control circuit module, the voltage detection feedback loop comprises an optical coupler and a voltage detection sampling circuit module, the output rectifier filter circuit module is connected to the optical coupler through the voltage detection sampling circuit module, and the optical coupler is connected to the PWM control circuit module. The present invention improves the performance of the driving power supply and realizes the miniaturization of the driving power supply.

Description

Technical Field

[0001] The present invention relates to the technical field of driving power supplies, and in particular to a driving power supply circuit based on a gallium nitride power chip. Background Art

[0002] In power electronic and electrical equipment, efficient power conversion is an important means to achieve environmental protection and energy saving. Efficient power conversion is achieved through efficient switching devices. At present, the switching devices in the driving power supply circuit generally use silicon-based power semiconductor devices. However, the performance of traditional silicon power devices has gradually reached a bottleneck, from transistors, field effect transistors, gate-controlled transistors IGBTs and diodes made of silicon, to the increasingly developed third-generation wide bandgap semiconductor material gallium nitride (GaN)-based switching devices. The third-generation gallium nitride device wide bandgap semiconductor device has a smaller on-resistance than the silicon material MOSFET and can withstand a higher switching frequency. Gallium nitride has properties such as a wide direct bandgap, strong atomic bonds, high thermal conductivity, high chemical stability (almost not corroded by any acid) and strong radiation resistance, and has broad prospects in the application of optoelectronics, high-temperature high-power devices and high-frequency microwave devices.

[0003] Power semiconductor devices are the foundation of power electronics technology and the core of power electronic equipment. During operation, they have two types of power losses: device switching loss and conduction loss. When the device works at high frequency, the main loss is turn-on and turn-off loss. In practical applications, the device must be turned on and off within a limited time, and the voltage and current must change instantly, otherwise the device will fail and may damage other system components. Therefore, as a switching device, a power semiconductor device must have the characteristics of fast switching speed, large current and voltage bearing capacity, and low operating loss.

[0004] Therefore, in order to break through the technical bottleneck of silicon-based power semiconductor devices, it is necessary to develop a driving power circuit with lower loss, higher power characteristics and miniaturization. Summary of the invention

[0005] In order to solve the above problems, the present invention proposes a driving power supply circuit based on a gallium nitride power chip, aiming to improve the performance of the driving power supply and realize the miniaturization of the driving power supply. The specific technical solution is as follows:

[0006] A driving power supply circuit based on a gallium nitride power chip comprises an EMI filtering and rectifying circuit module, an APFC active power factor correction circuit module, a PWM control circuit module, a power switch gallium nitride chip U4, a switching transformer T1A, and an output rectifying and filtering circuit module, which are sequentially connected in a direction from AC input to DC output, wherein the APFC active power factor correction circuit module realizes power factor correction by connecting to a PFC control circuit module, and a voltage detection feedback loop for output voltage detection feedback is arranged between the output rectifying and filtering circuit module and the PWM control circuit module, and the voltage detection feedback loop comprises an optical coupler and a voltage detection sampling circuit module, and the output rectifying and filtering circuit module is connected to the optical coupler via the voltage detection sampling circuit module, and the optical coupler is connected to the PWM control circuit module.

[0007] In the present invention, the EMI filtering and rectification circuit module includes an adjustable resistor VAR1, an excitation coil LF2, a capacitor CX1, an excitation coil LF1, series resistors R48-R47-R60, a capacitor CX2, and a chip rectifier bridge BD1, which are sequentially connected between the live wire and the neutral wire of the AC input.

[0008] In the present invention, the APFC active power factor correction circuit module includes a rectified voltage output positive line HB+ and a rectified voltage output negative line connected to the voltage output end of the patch rectifier bridge BD1, and the rectified voltage output positive line HB+ is sequentially provided with an iron core inductor L1, a positive temperature coefficient thermistor TH1, an iron core inductor T2B, and a pair of parallel diodes D10, and a resistor RS2 is provided on the rectified voltage output negative line, and the rectified voltage output positive line HB+ and the rectified voltage output negative line are respectively provided with a capacitor C29 and an enhanced N-MOS field effect transistor Q3, the drain of the enhanced N-MOS field effect transistor Q3 is connected to the rectified voltage output positive line HB+, and the source is connected to the rectified voltage output negative line, and a capacitor C35 is connected in parallel between the drain and the source of the enhanced N-MOS field effect transistor Q3.

[0009] In the present invention, the PFC control circuit module includes a power factor correction controller chip U8, the source lead resistor R64 of the enhanced N-MOS field effect transistor Q3 is connected to the gate of the enhanced N-MOS field effect transistor Q3 and then connected to the pin DRV of the power factor correction controller chip U8 through a diode D13 and a resistor R63 arranged in series, and a resistor R65 is connected in parallel at both ends of the diode D13 and the resistor R63 arranged in series; the pin VCC of the power factor correction controller chip U8 is connected to the PWM control circuit module.

[0010] In the present invention, the PWM control circuit module includes a quasi-resonant flyback controller chip U5, a voltage supply line is led out from the rectified voltage output positive line HB+ of the APFC active power factor correction circuit module at a position between the thermistor TH1 and the iron core inductor T2B, a diode D9 is connected between the voltage supply line and the output end of the rectified voltage output positive line HB+, the voltage supply line is connected to the pin VH of the quasi-resonant flyback controller chip U5 through series resistors R6-R13, a group of inductors T1B are led out from the switching transformer T1A, the positive end of the inductor T1B is connected to the pin Zcd / Opp of the quasi-resonant flyback controller chip U5 through a resistor R24 ​​and a diode D6, and the positive end of the inductor T1B is connected to the pin Zcd / Opp of the quasi-resonant flyback controller chip U5 through a forward-set diode D5, a diode D8, a transistor Q2 and a diode D3, respectively. The transistor Q2 is connected to the pin Vcc of the quasi-resonant flyback controller chip U5 and the pin Vcc of the power switch gallium nitride chip U4, and the diode D5 is connected in parallel with a capacitor C7 and a resistor R14 arranged in series, the base of the transistor Q2 is connected to the protection ground PGND through a voltage stabilizing diode ZD2, a resistor R45 is connected between the cathode of the diode D8 and the collector of the transistor Q2, the anode end of the diode D8 is connected to the protection ground PGND through capacitors C27 and C28 respectively, and the emitter of the transistor Q2 is connected to the pin VCC of the power factor correction controller chip U8 through a diode D11; the pin DRV of the quasi-resonant flyback controller chip U5 is connected to the pin PWM of the power switch gallium nitride chip U4 through a resistor R23, and the pin Cs of the quasi-resonant flyback controller chip U5 is connected to the pin SS of the power switch gallium nitride chip U4 through a resistor R26.

[0011] In the present invention, the pin Fault of the quasi-resonant flyback controller chip U5 is connected to a thermistor NTC1 with a negative temperature coefficient.

[0012] In the present invention, the primary side coil of the switching transformer T1A is connected between the rectified voltage output positive line HB+ and the pin DF of the power switch gallium nitride chip U4, and the secondary side coil of the switching transformer T1A is connected to the output rectifier filter circuit module; the diode D1, the resistor R5 and the capacitor C7 are connected in sequence between the pin DF of the power switch gallium nitride chip U4 and the rectified voltage output positive line HB+, and series resistors R1-R2 are arranged in parallel at both ends of the resistor R5 and the capacitor C7.

[0013] In the present invention, the output rectification and filtering circuit module includes a synchronous rectification controller chip U1, a DC voltage output positive line V+ and a DC voltage output negative line V- connected to the secondary side coil of the switching transformer T1A, an enhanced N-MOS field effect transistor Q1 is arranged on the DC voltage output negative line V-, capacitors EC2, capacitors C3, capacitors EC3 and excitation coil LF3 are arranged between the DC voltage output positive line V+ and the DC voltage output negative line V- in sequence, and the pin VG of the synchronous rectification controller chip U1 is connected to the enhanced N-MOS field effect transistor Q1. The gate of the enhanced N-MOS field effect transistor Q1 is connected, the pin VD of the synchronous rectification controller chip U1 is connected to the drain of the enhanced N-MOS field effect transistor Q1 through a resistor R10, the drain of the enhanced N-MOS field effect transistor Q1 is connected to the source of the enhanced N-MOS field effect transistor Q1 through a resistor R3 and a capacitor C4, the pin Vdd of the synchronous rectification controller chip U1 is connected to the DC voltage output positive line V+ through a resistor R9, and is connected to the voltage detection sampling circuit module through the resistor R9.

[0014] In the present invention, the voltage detection sampling circuit module includes a resistor R15, a resistor R20, and a voltage stabilizing diode U3 which are sequentially connected between the DC voltage output positive line V+ and the DC voltage output negative line V-; the resistor R20 is also connected to the light-emitting diode U2A of the optical coupler; the pin Fb of the quasi-resonant flyback controller chip U5 is connected to the phototransistor U2B of the optical coupler through the resistor R20; a resistor R12, a resistor R19, and a capacitor C8 which are arranged in series are connected in parallel at both ends after the resistor R15 and the resistor R20 are connected in series; the resistor R12 is connected to the common end of the voltage stabilizing diode U3 through a wire after being connected to the resistor R19.

[0015] Preferably, the switching transformer is a switching transformer manufactured using a planar process.

[0016] In the present invention, the driving power supply circuit further includes a constant current control circuit module, and an operational amplifier chip is arranged in the constant current control circuit module.

[0017] In the present invention, the power factor correction controller chip U8 adopts the NCP1654 chip or a similar PFC control chip, the quasi-resonant flyback controller chip U5 adopts the NCP1342 chip or a similar quasi-resonant flyback controller chip, the power switch gallium nitride chip U4 adopts the NV6125 chip or a similar power switch gallium nitride chip, the synchronous rectification controller chip U1 adopts the NCP4306 chip or a similar synchronous rectification controller chip, and the operational amplifier chip adopts the LM321 chip or a similar operational amplifier chip.

[0018] The beneficial effects of the present invention are:

[0019] First, the driving power supply circuit based on the gallium nitride power chip of the present invention has the advantages of fast switching speed, large current and voltage bearing capacity, and small working loss.

[0020] Secondly, the driving power supply circuit based on the gallium nitride power chip of the present invention, the switching transformer and the like are manufactured by planar technology, which is conducive to the miniaturization of the driving power supply. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a schematic diagram of the overall principle of a driving power supply circuit based on a gallium nitride power chip of the present invention;

[0022] Figure 2 It is a circuit diagram of a driving power supply circuit based on a gallium nitride power chip of the present invention;

[0023] Figure 3 yes Figure 1 and Figure 2 A partial enlarged view of the EMI filtering and rectification circuit module;

[0024] Figure 4 yes Figure 1 and Figure 2 A partial enlarged view of the APFC active power factor correction circuit module;

[0025] Figure 5 yes Figure 1 and Figure 2 A partial enlarged view of the PFC control circuit module;

[0026] Figure 6 yes Figure 1 and Figure 2 A partial enlarged view of the PWM control circuit module in FIG.

[0027] Figure 7 yes Figure 1 and Figure 2 A partial enlarged view of the power switch GaN chip U4;

[0028] Figure 8 yes Figure 1 and Figure 2 A partial enlarged view of the output rectifier filter circuit module and the voltage detection feedback loop (the photosensitive transistor U2B of the optocoupler in the voltage detection feedback loop is connected to Figure 6 In the PWM control circuit module). DETAILED DESCRIPTION

[0029] The specific implementation of the present invention is further described below in conjunction with the accompanying drawings and embodiments. The following embodiments are only used to more clearly illustrate the technical solution of the present invention, and cannot be used to limit the protection scope of the present invention.

[0030] like Figures 1 to 8 The figure shows an embodiment of a driving power supply circuit based on a gallium nitride power chip of the present invention, comprising an EMI filtering and rectifying circuit module, an APFC active power factor correction circuit module, a PWM control circuit module, a power switch gallium nitride chip U4, a switching transformer T1A, and an output rectifying and filtering circuit module, which are sequentially connected in the direction from AC input to DC output, wherein the APFC active power factor correction circuit module realizes power factor correction by connecting to a PFC control circuit module, and a voltage detection feedback loop for output voltage detection feedback is arranged between the output rectifying and filtering circuit module and the PWM control circuit module, and the voltage detection feedback loop comprises an optical coupler and a voltage detection sampling circuit module, and the output rectifying and filtering circuit module is connected to the optical coupler through the voltage detection sampling circuit module, and the optical coupler is connected to the PWM control circuit module.

[0031] In this embodiment, the EMI filtering and rectification circuit module includes an adjustable resistor VAR1, an excitation coil LF2, a capacitor CX1, an excitation coil LF1, series resistors R48-R47-R60, a capacitor CX2, and a chip rectifier bridge BD1, which are sequentially connected between the live wire and the neutral wire of the AC input.

[0032] In this embodiment, the APFC active power factor correction circuit module includes a rectified voltage output positive line HB+ and a rectified voltage output negative line connected to the voltage output end of the chip rectifier bridge BD1, and the rectified voltage output positive line HB+ is sequentially provided with an iron core inductor L1, a positive temperature coefficient thermistor TH1, an iron core inductor T2B, and a pair of parallel diodes D10, and a resistor RS2 is provided on the rectified voltage output negative line, and the rectified voltage output positive line HB+ and the rectified voltage output negative line are respectively provided with a capacitor C29 and an enhanced N-MOS field effect transistor Q3, the drain of the enhanced N-MOS field effect transistor Q3 is connected to the rectified voltage output positive line HB+, and the source is connected to the rectified voltage output negative line, and a capacitor C35 is connected in parallel between the drain and the source of the enhanced N-MOS field effect transistor Q3.

[0033] In this embodiment, the PFC control circuit module includes a power factor correction controller chip U8, the source lead resistor R64 of the enhanced N-MOS field effect transistor Q3 is connected to the gate of the enhanced N-MOS field effect transistor Q3 and then connected to the pin DRV of the power factor correction controller chip U8 through a diode D13 and a resistor R63 arranged in series, and a resistor R65 is connected in parallel at both ends of the diode D13 and the resistor R63 arranged in series; the pin VCC of the power factor correction controller chip U8 is connected to the PWM control circuit module.

[0034] In this embodiment, the PWM control circuit module includes a quasi-resonant flyback controller chip U5, a voltage supply line is led out from the rectified voltage output positive line HB+ of the APFC active power factor correction circuit module at a position between the thermistor TH1 and the iron-core inductor T2B, a diode D9 is connected between the voltage supply line and the output end of the rectified voltage output positive line HB+, the voltage supply line is connected to the pin VH of the quasi-resonant flyback controller chip U5 through series resistors R6-R13, a group of inductors T1B are led out from the switching transformer T1A, the positive end of the inductor T1B is connected to the pin Zcd / Opp of the quasi-resonant flyback controller chip U5 through a resistor R24 ​​and a diode D6, and the positive end of the inductor T1B is respectively connected to the pin Zcd / Opp of the quasi-resonant flyback controller chip U5 through a forward-set diode D5, a diode D8, a transistor Q2 and a diode D3. The transistor Q2 is connected to the pin Vcc of the quasi-resonant flyback controller chip U5 and the pin Vcc of the power switch gallium nitride chip U4, and the diode D5 is connected in parallel with a capacitor C7 and a resistor R14 arranged in series, the base of the transistor Q2 is connected to the protection ground PGND through a voltage stabilizing diode ZD2, a resistor R45 is connected between the cathode of the diode D8 and the collector of the transistor Q2, the anode end of the diode D8 is connected to the protection ground PGND through capacitors C27 and C28 respectively, and the emitter of the transistor Q2 is connected to the pin VCC of the power factor correction controller chip U8 through a diode D11; the pin DRV of the quasi-resonant flyback controller chip U5 is connected to the pin PWM of the power switch gallium nitride chip U4 through a resistor R23, and the pin Cs of the quasi-resonant flyback controller chip U5 is connected to the pin SS of the power switch gallium nitride chip U4 through a resistor R26.

[0035] In this embodiment, the pin Fault of the quasi-resonant flyback controller chip U5 is connected to a thermistor NTC1 with a negative temperature coefficient.

[0036] In this embodiment, the primary side coil of the switching transformer T1A is connected between the rectified voltage output positive line HB+ and the pin DF of the power switch gallium nitride chip U4, and the secondary side coil of the switching transformer T1A is connected to the output rectifier filter circuit module; the diode D1, the resistor R5 and the capacitor C7 are connected in sequence between the pin DF of the power switch gallium nitride chip U4 and the rectified voltage output positive line HB+, and series resistors R1-R2 are arranged in parallel at both ends of the resistor R5 and the capacitor C7.

[0037] In this embodiment, the output rectification and filtering circuit module includes a synchronous rectification controller chip U1, a DC voltage output positive line V+ and a DC voltage output negative line V- connected to the secondary side coil of the switching transformer T1A, an enhanced N-MOS field effect transistor Q1 is arranged on the DC voltage output negative line V-, and capacitors EC2, C3, EC3 and excitation coil LF3 are arranged in sequence between the DC voltage output positive line V+ and the DC voltage output negative line V-, and the pin VG of the synchronous rectification controller chip U1 is connected to the enhanced N-MOS field effect transistor Q1. The gate of the enhanced N-MOS field effect transistor Q1 is connected, the pin VD of the synchronous rectification controller chip U1 is connected to the drain of the enhanced N-MOS field effect transistor Q1 through a resistor R10, the drain of the enhanced N-MOS field effect transistor Q1 is connected to the source of the enhanced N-MOS field effect transistor Q1 through a resistor R3 and a capacitor C4, the pin Vdd of the synchronous rectification controller chip U1 is connected to the DC voltage output positive line V+ through a resistor R9, and is connected to the voltage detection sampling circuit module through the resistor R9.

[0038] In this embodiment, the voltage detection sampling circuit module includes a resistor R15, a resistor R20, and a voltage stabilizing diode U3 which are sequentially connected between the DC voltage output positive line V+ and the DC voltage output negative line V-; the resistor R20 is also connected to the light-emitting diode U2A of the optocoupler; the pin Fb of the quasi-resonant flyback controller chip U5 is connected to the phototransistor U2B of the optocoupler through the resistor R20; a resistor R12, a resistor R19, and a capacitor C8 which are arranged in series are connected in parallel at both ends after the resistor R15 and the resistor R20 are connected in series; the resistor R12 is connected to the resistor R19 and then connected to the common end of the voltage stabilizing diode U3 through a wire.

[0039] Preferably, the switching transformer is a switching transformer manufactured using a planar process.

[0040] In this embodiment, the driving power supply circuit further includes a constant current control circuit module, and an operational amplifier chip is disposed in the constant current control circuit module.

[0041] In this embodiment, the power factor correction controller chip U8 adopts the NCP1654 chip or a similar PFC control chip, the quasi-resonant flyback controller chip U5 adopts the NCP1342 chip or a similar quasi-resonant flyback controller chip, the power switch gallium nitride chip U4 adopts the NV6125 chip or a similar power switch gallium nitride chip, the synchronous rectification controller chip U1 adopts the NCP4306 chip or a similar synchronous rectification controller chip, and the operational amplifier chip adopts the LM321 chip or a similar operational amplifier chip.

[0042] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the technical principles of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A driving power supply circuit based on a gallium nitride power chip, characterized in that: It includes an EMI filtering and rectifying circuit module, an APFC active power factor correction circuit module, a PWM control circuit module, a power switch gallium nitride chip U4, a switch transformer T1A, and an output rectifying and filtering circuit module, which are connected in sequence from AC input to DC output. The APFC active power factor correction circuit module realizes power factor correction by connecting to a PFC control circuit module. A voltage detection feedback loop for output voltage detection feedback is provided between the output rectifying and filtering circuit module and the PWM control circuit module. The voltage detection feedback loop includes an optical coupler and a voltage detection sampling circuit module. The output rectifying and filtering circuit module is connected to the optical coupler through the voltage detection sampling circuit module, and the optical coupler is connected to the PWM control circuit module. The PWM control circuit module includes a quasi-resonant flyback controller chip U5. The APFC has A voltage supply line is led out from the rectified voltage output positive line HB+ of the source power factor correction circuit module at a position between the thermistor TH1 and the iron core inductor T2B, and a diode D9 is connected between the voltage supply line and the output end of the rectified voltage output positive line HB+; a group of inductors T1B are led out from the switching transformer T1A, and the positive end of the inductor T1B is connected to the pin Zcd / Opp of the quasi-resonant flyback controller chip U5 through a resistor R24 ​​and a diode D6; the pin Fault of the quasi-resonant flyback controller chip U5 is connected to the thermistor NTC1 with a negative temperature coefficient; the primary side coil of the switching transformer T1A is connected between the rectified voltage output positive line HB+ and the pin DF of the power switch gallium nitride chip U4, and the secondary side coil of the switching transformer T1A is connected to the output rectifier and filter circuit module.

2. A driving power supply circuit based on a gallium nitride power chip according to claim 1, characterized in that: The EMI filtering and rectifying circuit module includes an adjustable resistor VAR1, an excitation coil LF2, a capacitor CX1, an excitation coil LF1, series resistors R48-R47-R60, a capacitor CX2, and a surface-mount rectifier bridge BD1, which are sequentially connected between the live wire and the neutral wire of the AC input.

3. The driving power supply circuit based on gallium nitride power chip according to claim 2, characterized in that: The APFC active power factor correction circuit module includes a rectified voltage output positive line HB+ and a rectified voltage output negative line connected to the voltage output end of the patch rectifier bridge BD1. The rectified voltage output positive line HB+ is sequentially provided with an iron core inductor L1, a positive temperature coefficient thermistor TH1, an iron core inductor T2B, and a pair of parallel diodes D10. The rectified voltage output negative line is provided with a resistor RS2. The rectified voltage output positive line HB+ and the rectified voltage output negative line are respectively provided with a capacitor C29 and an enhanced N-MOS field effect transistor Q3. The drain of the enhanced N-MOS field effect transistor Q3 is connected to the rectified voltage output positive line HB+, and the source is connected to the rectified voltage output negative line. A capacitor C35 is connected in parallel between the drain and the source of the enhanced N-MOS field effect transistor Q3.

4. The driving power supply circuit based on gallium nitride power chip according to claim 3, characterized in that: The PFC control circuit module includes a power factor correction controller chip U8. The source lead resistor R64 of the enhanced N-MOS field effect transistor Q3 is connected to the gate of the enhanced N-MOS field effect transistor Q3 and then connected to the pin DRV of the power factor correction controller chip U8 through a diode D13 and a resistor R63 arranged in series. A resistor R65 is connected in parallel at both ends of the diode D13 and the resistor R63 arranged in series; the pin VCC of the power factor correction controller chip U8 is connected to the PWM control circuit module.

5. The driving power supply circuit based on gallium nitride power chip according to claim 4, characterized in that: The voltage supply line is connected to the pin VH of the quasi-resonant flyback controller chip U5 through series resistors R6-R13, and the positive terminal of the inductor T1B is connected to the pin Vcc of the quasi-resonant flyback controller chip U5 and the pin Vcc of the power switch gallium nitride chip U4 respectively through the forward-set diode D5, the diode D8, the transistor Q2 and the diode D3, and the diode D5 is connected in parallel with a capacitor C7 and a resistor R14 set in series, the base of the transistor Q2 is connected to the protection ground PGND through the voltage stabilizing diode ZD2, and the diode D8 is connected to the protection ground PGND. A resistor R45 is connected between the cathode and the collector of the transistor Q2, the anode end of the diode D8 is connected to the protective ground PGND through capacitors C27 and C28 respectively, and the emitter of the transistor Q2 is connected to the pin VCC of the power factor correction controller chip U8 through a diode D11; the pin DRV of the quasi-resonant flyback controller chip U5 is connected to the pin PWM of the power switch gallium nitride chip U4 through a resistor R23, and the pin Cs of the quasi-resonant flyback controller chip U5 is connected to the pin SS of the power switch gallium nitride chip U4 through a resistor R26.

6. The driving power supply circuit based on gallium nitride power chip according to claim 5, characterized in that: A diode D1, a resistor R5 and a capacitor C7 are sequentially connected between the pin DF of the power switch gallium nitride chip U4 and the rectified voltage output positive line HB+, and a series resistor R1-R2 is arranged in parallel at both ends of the resistor R5 and the capacitor C7.

7. The driving power supply circuit based on gallium nitride power chip according to claim 6, characterized in that: The output rectification and filtering circuit module includes a synchronous rectification controller chip U1, a DC voltage output positive line V+ and a DC voltage output negative line V- connected to the secondary side coil of the switching transformer T1A, an enhanced N-MOS field effect transistor Q1 is arranged on the DC voltage output negative line V-, capacitors EC2, C3, EC3 and an excitation coil LF3 are arranged in sequence between the DC voltage output positive line V+ and the DC voltage output negative line V-, and a pin VG of the synchronous rectification controller chip U1 is connected to the enhanced N -MOS field effect transistor Q1, the pin VD of the synchronous rectification controller chip U1 is connected to the drain of the enhancement N-MOS field effect transistor Q1 through a resistor R10, the drain of the enhancement N-MOS field effect transistor Q1 is connected to the source of the enhancement N-MOS field effect transistor Q1 through a resistor R3 and a capacitor C4, the pin Vdd of the synchronous rectification controller chip U1 is connected to the DC voltage output positive line V+ through a resistor R9, and is connected to the voltage detection sampling circuit module through the resistor R9.

8. The driving power supply circuit based on gallium nitride power chip according to claim 7, characterized in that: The voltage detection sampling circuit module includes a resistor R15, a resistor R20, and a voltage stabilizing diode U3 which are sequentially connected between the DC voltage output positive line V+ and the DC voltage output negative line V-; the resistor R20 is also connected to the light emitting diode U2A of the optical coupler; the pin Fb of the quasi-resonant flyback controller chip U5 is connected to the phototransistor U2B of the optical coupler through the resistor R20; a resistor R12, a resistor R19, and a capacitor C8 which are arranged in series are connected in parallel at both ends after the resistor R15 and the resistor R20 are connected in series; the resistor R12 is connected to the common end of the voltage stabilizing diode U3 through a wire after being connected to the resistor R19.

9. The driving power supply circuit based on gallium nitride power chip according to claim 8, characterized in that: The switching transformer is a switching transformer manufactured by a planar process.

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