A GaN radiation-resistant driver circuit based on discrete devices

Abstract

The application relates to a discrete device-based GaN anti-radiation driving circuit, which comprises a PWM output circuit, an isolation driving circuit, a driving enhancement circuit and a level conversion circuit. The PWM output circuit carries out pulse width modulation according to an output voltage feedback signal of a switching power supply and outputs a driving control waveform, and can be adapted to single-end or bridge type topological structures; the isolation driving circuit realizes isolation and lossless transmission of a driving signal through a direct-current isolation circuit, an isolation transformer and a compensation circuit, thereby guaranteeing stable transient and steady-state closed-loop control of a DC / DC converter; the driving enhancement circuit adopts a complementary totem pole transistor structure, carries out current amplification on the driving signal, realizes conversion of driving capacity from weak to strong, and improves driving efficiency of a power device; and the application sets the level conversion circuit aiming at characteristic switching characteristics of the GaN power device, optimizes driving, adjusts an edge rate of the driving signal and suppresses electromagnetic interference, so that stable and efficient driving of the GaN power device is realized.

Description

Technical Field

[0001] This invention relates to the field of switching power supply circuit technology, specifically a GaN radiation-resistant drive circuit based on discrete components. Background Technology

[0002] Gallium nitride (GaN) is a third-generation wide-bandgap semiconductor material with strong stability and radiation resistance, as well as high electron mobility, low on-state resistance, and high thermal conductivity. Therefore, GaN devices have broad application prospects in the field of switching power supplies that pursue high frequency, miniaturization, and low power consumption.

[0003] Reliability is a core performance indicator for switching power supplies. With the continuous expansion of power system application environments, the reliability requirements for DC / DC converters are becoming increasingly stringent. The new generation of power supplies equipped with GaN devices places even more stringent standards on circuit reliability design. As the core unit ensuring the normal operation of GaN devices, the driver circuit needs to balance reliability and radiation requirements in its design, making it a current research hotspot in the GaN device field.

[0004] Compared to silicon devices, GaN devices have a lower threshold voltage of approximately 1.5V and a maximum gate drive voltage of approximately 5V, placing extremely stringent requirements on drive signal specifications. Traditional MOSFET drive circuits cannot match this gate drive voltage range and lack adjustable parasitic parameter suppression methods, which significantly impacts the loop stability and control reliability of GaN-based switching power supplies. Traditional GaN driver chips have poor drive performance and fast response capabilities, generally limiting their use to dedicated driver chips and hindering large-scale deployment. For applications in irradiated environments, the chips require additional irradiation hardening treatment. Currently, mature radiation-hardened GaN driver chips are scarce in the market, and robustness verification for related irradiation drives is insufficient. Furthermore, the high cost of driver chips, especially in space irradiation applications, significantly restricts the implementation and widespread adoption of next-generation high-performance GaN power supplies.

[0005] Therefore, in order to meet the requirements of high reliability, low cost and adaptability to the gate drive characteristics of GaN devices in space irradiation environment, it is urgent to design a brand-new drive circuit. Summary of the Invention

[0006] To address the shortcomings of existing technologies, the present invention aims to provide a GaN radiation-hardened drive circuit based on discrete devices.

[0007] To achieve the above objectives, the present invention adopts the following technical solution: A GaN radiation-hardened drive circuit based on discrete devices includes a PWM output circuit, an isolation drive circuit, a drive enhancement circuit, and a level conversion circuit. The PWM output circuit is used to receive the power supply voltage feedback signal and output the drive control signal. Its output terminal can be selectively connected to the input terminal of the isolation drive circuit or the input terminal of the drive enhancement circuit. The isolation drive circuit is used to electrically isolate the drive control signal output by the PWM output circuit, and its output terminal is connected to the input terminal of the drive enhancement circuit. The drive enhancement circuit uses a totem pole structure composed of complementary transistors to amplify the current of the isolated drive control signal, and its output is connected to the input of the level conversion circuit. The level conversion circuit, through the cooperation of the RC charging and discharging structure and the voltage clamping structure, outputs a drive signal that is compatible with GaN power devices and can achieve high-level clamping on and negative-level shutdown.

[0008] As a further improvement to the above technical solution, the isolation drive circuit includes a DC blocking circuit, an isolation transformer T1, and a compensation circuit; The isolation transformer T1 includes primary windings T1-1 and T1-2 and secondary output windings T1-3 and T1-4; the primary winding terminal T1-1 is connected to the DC blocking circuit, and the secondary winding terminal T1-2 is connected to the primary ground; the secondary winding terminal T1-3 is connected to the compensation circuit, and the secondary winding terminal T1-4 is connected to the secondary ground. The DC blocking circuit includes a diode V1 and a DC blocking capacitor C1; the anode of the diode V1 is connected to the primary winding terminal T1-1, and the cathode is connected to the drive control signal point A; the DC blocking capacitor C1 is connected in parallel with the diode V1. The compensation circuit includes a compensation capacitor C2 and a bleeder resistor R1; one end of the compensation capacitor C2 is connected to the same terminal T1-3 of the secondary winding of the isolation transformer T1, and the other end is connected to the isolation drive signal point B; the bleeder resistor R1 is connected in parallel with the compensation capacitor C2.

[0009] As a further improvement to the above technical solution, the drive enhancement circuit includes voltage divider resistor R2, voltage divider resistor R3, secondary power supply Vs, transistor V2, and transistor V3. The voltage divider resistors R2 and R3 are connected in series; one end of the voltage divider resistor R2 is connected to the signal output terminal of the isolation drive circuit, and one end of the voltage divider resistor R3 is connected to the secondary output ground; the series junction of the voltage divider resistors R2 and R3 is connected to the base of both transistor V2 and transistor V3; the collector of transistor V2 is connected to the secondary power supply; the emitter of transistor V2 is connected to the emitter of transistor V3 and forms the signal output terminal of the drive enhancement circuit; the collector of transistor V3 is connected to the secondary output ground.

[0010] As a further improvement to the above technical solution, the level conversion circuit includes a resistor R4, a capacitor C3, a diode V4, a resistor R5, a Zener diode V5, and a Zener diode V6. The resistor R4 is connected in series with the capacitor C3; one end of the capacitor C3 is connected to the cathode of the diode V4 and the signal output terminal of the drive enhancement circuit; one end of the resistor R4 is connected to the anode of the diode V4, one end of the resistor R5 and the cathode of the Zener diode V5, forming a GaN drive signal output terminal; the anode of the Zener diode V5 is connected to the anode of the Zener diode V6; the other end of the resistor R5 and the cathode of the Zener diode V6 are both connected to the secondary output ground.

[0011] As a further improvement to the above technical solution, the diode V1 is a 1N4148 switching diode.

[0012] As a further improvement to the above technical solution, the primary winding and secondary winding of the isolation transformer T1 are configured according to a preset turns ratio to match the amplitude of the isolation drive voltage.

[0013] As a further improvement to the above technical solution, transistor V2 is an NPN type JHGC3904 transistor; transistor V3 is a PNP type JHGC3906 transistor.

[0014] As a further improvement to the above technical solution, the secondary power supply adopts an independent power supply or a bootstrap power supply method.

[0015] As a further improvement to the above technical solution, diode V4 is a 1N4148 switching diode; Zener diodes V5 and V6 are both BZ5230B Zener diodes.

[0016] As a further improvement to the above technical solution, when applied to a half-bridge topology, two sets of the GaN radiation-resistant drive circuits are configured. The signal output terminals of the two sets of GaN radiation-resistant drive circuits output two drive signals respectively to drive the upper and lower bridge arm GaN power devices of the half-bridge topology.

[0017] Compared with the prior art, the advantages of the present invention are: (1) This invention is applicable to GaN switching power supply products with single-ended or bridge topology, and has a wider range of applications and higher flexibility in adapting to operating conditions. For application scenarios requiring electrical isolation, the turns ratio of the primary winding and secondary winding is set by the isolation transformer T1, and the PWM drive signal is proportionally isolated and coupled out. Then, the isolated drive of the GaN device is completed through the drive enhancement circuit and the level conversion circuit. For scenarios without isolation requirements, the PWM drive signal can be directly sent to the drive enhancement circuit and the level conversion circuit to realize the direct drive of the GaN device.

[0018] (2) This invention pre-divides and regulates the input drive signal using voltage divider resistors in the drive enhancement circuit, ensuring the safety of the drive signal. Simultaneously, it utilizes the current amplification characteristics of complementary transistors to achieve a weak-to-strong conversion of the drive signal, improving the circuit's driving capability. A level conversion circuit converts the pre-divided drive signal into a drive signal suitable for GaN devices. When the PWM input signal is high, the GaN drive voltage is clamped at approximately 5V, ensuring the safe turn-on of the GaN device. When the PWM input signal is low, the GaN drive voltage is negative, ensuring reliable turn-off of the GaN device.

[0019] (3) This invention does not require complex circuit design, completely abandons dedicated GaN driver chips and irradiation hardening chips, and can achieve efficient driving of GaN devices using only resistors, capacitors, diodes, transistors and magnetic discrete devices. The device selection is highly flexible, and the device is not sensitive to the irradiation environment, has strong radiation resistance, and is lower in cost, resulting in a good cost performance. Attached Figure Description

[0020] Figure 1 This is a circuit diagram of a traditional half-bridge DC / DC main topology. Figure 2 This is a circuit schematic diagram of the GaN radiation-hardened drive circuit based on discrete devices according to the present invention. Figure 3 This is a schematic diagram of the practical application circuit of the GaN radiation-hardened drive circuit based on discrete devices according to the present invention. Figure 4 The above is a system simulation waveform diagram corresponding to an embodiment of the present invention. Figure 5 The measured waveforms of the prototype corresponding to the embodiments of the present invention. Figure 1 ; Figure 6 The measured waveforms of the prototype corresponding to the embodiments of the present invention. Figure 2 . Detailed Implementation

[0021] The present invention will be further described below with reference to the accompanying drawings: Gallium nitride (GaN), as a third-generation wide-bandgap semiconductor material, possesses excellent radiation resistance, making it suitable for applications in space irradiation environments. Traditional silicon device driving schemes and commercially available dedicated GaN driver chips generally suffer from weak radiation resistance, easy parameter drift, high cost, and poor reliability. To address these issues, this invention proposes a GaN radiation-hardened driver circuit based on discrete components. This circuit is suitable for single-ended or bridge topologies and enables efficient driving of GaN power devices. The entire circuit consists only of discrete components such as resistors, capacitors, diodes, transistors, and magnetic materials, eliminating the need for a dedicated driver chip and effectively ensuring the circuit's radiation resistance and operational reliability. This invention can be applied in space irradiation environments, significantly simplifying GaN driver circuits, avoiding the radiation performance drift problems associated with radiation-hardened driver chips, and substantially reducing costs.

[0022] Traditional half-bridge DC / DC main topology, such as Figure 1 As shown, this topology consists of two power switching devices connected in a totem pole structure. The midpoint of the connection between the two power switching devices serves as the power output (the area within the dashed box in the figure). The upper arm switch V1 and the lower arm switch V2 are driven by complementary control signals. The electrical energy is coupled and transmitted to the secondary side of the circuit through a transformer, and then rectified and filtered by a Schottky diode and the output LC to finally output a suitable and stable DC voltage.

[0023] like Figure 2 The GaN radiation-hardened drive circuit based on discrete devices shown includes a PWM output circuit, an isolation drive circuit, a drive enhancement circuit, and a level conversion circuit.

[0024] The PWM output circuit is suitable for single-ended or bridge topologies. It performs pulse width modulation based on the output voltage feedback signal from the switching power supply and outputs a drive control signal (point A). This circuit can be optionally connected to an isolation drive circuit depending on system isolation requirements. When no isolation is required, the PWM control signal at point A is directly connected to the input of the drive enhancement circuit, passing sequentially through the drive enhancement circuit and the level conversion circuit to achieve non-isolated drive of the GaN device. When applied to a half-bridge topology, the PWM output circuit outputs a square wave drive control signal (point A) with an amplitude of 10V.

[0025] The input terminal of the isolation drive circuit is connected to the drive control signal of the PWM output circuit, and the output terminal is connected to the drive enhancement circuit. The isolation drive circuit achieves isolation and distortion-free transmission of the drive signal through a DC blocking circuit, an isolation transformer, and a compensation circuit, ensuring the stability of the transient and steady-state closed-loop control of the DC / DC converter.

[0026] The input terminal of the drive enhancement circuit is connected to the isolated drive signal after voltage division, and the output terminal is connected to the level conversion circuit. By improving the drive load capacity, the drive power is amplified, and the enhanced drive signal (point C) is output.

[0027] The level conversion circuit includes a drive optimization unit and a level conversion unit, which can adjust the switching rate of the drive waveform, suppress electromagnetic interference, and finally output a drive signal (point D) adapted to the GaN device. Since the bridge circuit requires two control signals, VgsA and VgsB, to drive the upper and lower bridge arm switches respectively, two sets of GaN radiation-hardened drive circuits based on discrete components are needed. This invention addresses the unique switching characteristics of GaN power devices by implementing a level conversion circuit. Through drive optimization and level conversion, the edge rate of the drive signal is adjusted, and electromagnetic interference is suppressed, achieving stable and efficient driving of the GaN power device.

[0028] As a further improvement to the above technical solution, the isolation drive circuit includes a DC blocking circuit, an isolation transformer T1, and a compensation circuit; the drive signal is coupled and transformed by the isolation transformer T1 to output an isolation drive signal (point B), and the voltage amplitude at this point is determined by the winding turns ratio of the isolation transformer T1.

[0029] The isolation transformer T1 includes primary windings T1-1 and T1-2 and secondary output windings T1-3 and T1-4. The primary winding terminal T1-1 is connected to the DC blocking circuit, and the secondary winding terminal T1-2 is connected to the primary ground. The secondary winding terminal T1-3 is connected to the compensation circuit, and the secondary winding terminal T1-4 is connected to the secondary ground. The DC blocking circuit includes a diode V1 and a DC blocking capacitor C1. The anode of diode V1 is connected to the primary winding terminal T1-1, and the cathode is connected to the drive control signal point A. The DC blocking capacitor C1 is connected in parallel with the diode V1. The compensation circuit includes a compensation capacitor C2 and a bleed resistor R1. One end of the compensation capacitor C2 is connected to the secondary winding terminal T1-3 of the isolation transformer T1, and the other end is connected to the isolation drive signal point B. The bleed resistor R1 is connected in parallel with the compensation capacitor C2.

[0030] As a further improvement to the above technical solution, the drive enhancement circuit includes voltage divider resistors R2 and R3, a secondary power supply Vs, transistors V2 and V3. Transistors V2 and V3 are totem-pole transistors. Voltage divider resistors R2 and R3 are connected in series; one end of voltage divider resistor R2 is connected to the isolation drive signal point B, and one end of voltage divider resistor R3 is connected to the secondary output ground; the midpoint of the series connection of voltage divider resistors R2 and R3 is simultaneously connected to the base of transistor V2 and the base of transistor V3; the collector of transistor V2 is connected to the secondary power supply Vs; the emitter of transistor V2 and the emitter of transistor V3 are shorted to the drive signal (point C); the collector of transistor V3 is connected to the secondary output ground.

[0031] As a further improvement to the above technical solution, the level conversion circuit includes a resistor R4, a capacitor C3, a diode V4, a resistor R5, a Zener diode V5, and a Zener diode V6; the resistor R4 and the capacitor C3 are connected in series; one end of the capacitor C3 is connected to the cathode of the diode V4 and the drive signal (point C); one end of the resistor R4 is connected to the anode of the diode V4, one end of the resistor R5, and the cathode of the Zener diode V5, and this connection point forms the GaN drive signal (point D); the anode of the Zener diode V5 is connected to the anode of the Zener diode V6; the other end of the resistor R5 and the cathode of the Zener diode V6 are both connected to the secondary output ground.

[0032] The above-described GaN radiation-hardened drive circuit based on discrete devices will be further described in detail below with reference to specific embodiments.

[0033] In this embodiment, diode V1 is selected as a switching diode of model 1N4148; when the input drive signal V a When the duty cycle is D, the DC voltage Vc across the DC blocking capacitor C1 satisfies the calculation formula: ; The turns ratio of the primary and secondary windings of isolation transformer T1 is set to N, and the DC blocking capacitor is used. The voltage Vb of the isolation drive signal at point B can be obtained as follows: ; The drive enhancement circuit determines the voltage at point C of the drive signal by using the voltage divider values ​​of resistors R2 and R3. Assuming the transistor's emitter-junction voltage drop is 0.6V, The calculation formula is: ; In this embodiment, the secondary power supply Vs can be either an independent power supply or a bootstrap power supply. Transistors V2 and V3 are complementary totem-pole structures, wherein transistor V2 is an NPN transistor JHGC3904 and transistor V3 is a PNP transistor JHGC3906.

[0034] In this embodiment, diode V4 in the level conversion circuit is a switching diode 1N4148, used to provide a fast discharge path. Diodes V5 and V6 are Zener diodes BZ5230B; the resistance value of resistor R4 is used to adjust the switching speed of the drive; the charging and discharging of capacitor C3 will generate a negative voltage at the GaN drive signal (point D), achieving reliable GaN turn-off. When the drive signal (point C) is high, the right side of capacitor C3 is high, the Zener diode V5 is broken down, and the voltage of the GaN drive signal (point D) is clamped at a potential level of about 5V, ensuring reliable turn-on of the GaN device. When the drive signal (point C) is low, in order to maintain the level across capacitor C3 unchanged and make the output voltage at point D negative, the right side of C3 becomes negative, ensuring reliable turn-off of the GaN device. The high level Vg of the GaN gate drive signal (point D) is: ; The practical application principle diagram of this invention is as follows: Figure 3 As shown, this power supply scheme adopts a half-bridge main topology and a secondary PWM control strategy. The PWM control chip is powered by an RCC auxiliary source, and the power supply output voltage is directly sampled through a resistor divider and then sent to the chip's FB pin to achieve closed-loop feedback control of the output voltage. To improve efficiency, all primary-side power switches in this embodiment use GaN power devices. Therefore, the GaN isolation drive unit is designed using the discrete device-based GaN radiation-hardened drive circuit described in this invention. Figure 3 As shown, the specific driving process is as follows: The PWM controller outputs 10V bridge complementary drive signals OUTA and OUTB. After being transformed by the isolation drive circuit, the two signals output 5V bridge drive square wave signals VgsA and VgsB with amplitudes adapted to the GaN devices. Among them, the high-side drive signal VgsA uses the midpoint potential Vtp of the bridge arm as a reference potential and is used to drive the GaN power devices on the upper arm of the half-bridge topology.

[0035] In this embodiment, the winding connection of the isolation transformer T1 is adapted: the primary non-signal terminal T1-2 is connected to the PWM controller OUTA and OUTB signal grounds; the secondary non-signal terminal T1-4 is connected to the power input ground Vgnd and the bridge arm midpoint potential Vtp respectively, depending on the reference ground of the drive signal; the diode V1 in the DC blocking circuit is a 1N4148 switching diode, and its cathode is connected to the PWM signals OUTA and OUTB respectively; the DC blocking capacitor C1 has a value of 0.15uF and is connected in parallel with the diode V1; the compensation capacitor C2 has a value of 0.15uF, one end is connected to the secondary winding non-signal terminal T1-3 of the isolation transformer T1, and the other end is connected to the isolation drive signal at point B; the bleeder resistor R1 has a value of 330Ω and is connected in parallel with the compensation capacitor.

[0036] Input drive signal V aIf OUTA and OUTB are the capacitors with a duty cycle of D and a value of 0.45, then the DC voltage Vc across the DC blocking capacitor is: ; If the primary-to-secondary turns ratio N of transformer T1 is set to 1:1, then the isolation drive signal (point B) voltage Vb is: ; In this embodiment, the voltage divider resistors R2 and R3 in the drive enhancement circuit are 4kΩ and 10kΩ respectively, and the voltage of the drive signal at point C is determined by the voltage division between them. The secondary power supply Vs has two configurations: the low-side power supply Vs uses a 10V independent power supply, and the high-side power supply Vs adopts a bootstrap power supply mode. Transistors V2 and V3 are complementary totem-pole structures, where transistor V2 is a JHGC3904 NPN transistor and transistor V3 is a JHGC3906 PNP transistor. When the base level of the transistors rises, the emitter of the NPN transistor V2 is forward biased, and the base current of the transistor... Amplified by β times, the secondary power supply Vs outputs a larger collector drive current Ic: ; ; When the base level of the transistor decreases, the emitter of the PNP transistor V3 is forward biased and turned on. The drive signal at point C forms a discharge circuit through the transistor V3, realizing the drive turn-off function.

[0037] In this embodiment, the parameters of the level conversion circuit are configured as follows: Diode V4 is a 1N4148 switching diode, used to provide a fast gate discharge path; resistor R5 is 10kΩ, used to reduce gate interference; Zener diodes V5 and V6 are BZ5230B; resistor R4 is 100Ω, used to adjust the edge rate of the drive signal; capacitor C3, relying on its charging and discharging characteristics, will generate a negative voltage on the GaN drive signal at point D. When the drive signal at point C is high, the right side of capacitor C3 is high, the Zener diode V5 is broken down, clamping the voltage of the GaN drive signal at point D to a potential level of about 5V, ensuring the reliable turn-on of the GaN device. When the drive signal at point C is low, in order to maintain the level across capacitor C3, the potential at the right end of C3 becomes negative, realizing the reliable turn-off of the GaN device. The formula for calculating the high-level output voltage Vg of the GaN gate drive signal at point D is: ; in, This is the breakdown voltage of the Zener diode. This is the forward voltage drop of the diode.

[0038] The discrete-device-based GaN radiation-hardened drive circuit designed in this invention enables reliable turn-on and turn-off of GaN power switches in the upper and lower arms of a half-bridge topology. This effectively improves the efficiency of the switching power supply while significantly simplifying the circuit complexity of traditional GaN drive architectures and reducing design difficulty. The circuit simulation results in this embodiment are as follows: Figure 4 As shown, the DC / DC converter can stably output a 28V DC voltage Vout, and the waveform characteristics of the high-side drive signal VgsA relative to the bridge arm midpoint reference potential Vtp meet the design requirements. The measured waveform of the actual product is shown below. Figure 5 and Figure 6 As shown, the waveforms of the low-side drive signal VgsB and the reference potential Vtp at the midpoint of the bridge arm meet the design requirements, fully verifying the feasibility and stability of the drive circuit described in this invention.

[0039] Meanwhile, the circuit design and actual application products in this embodiment have passed the total dose test of 100 klad (Si) and the single-particle test of 75 MeV•cm2 / mg, with all performance indicators normal, proving that the present invention has excellent radiation resistance and can be reliably applied to complex space irradiation conditions for a long time, greatly improving the practicality and reliability of GaN power supply systems. This invention completely abandons dedicated radiation-resistant GaN driver chips, using only resistors, capacitors, diodes, transistors, and discrete magnetic components to build the drive link, thus achieving radiation-resistant drive of GaN devices. This invention effectively avoids the problems of parameter drift and performance degradation of dedicated chips under irradiation environments. The overall structure is simple, highly reliable, versatile, and low-cost, improving the environmental adaptability and engineering practical value of space GaN power supply systems.

[0040] The above-described embodiments are merely preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Various modifications and improvements made by those skilled in the art to the technical solutions of the present invention without departing from the spirit of the present invention should fall within the protection scope defined by the claims of the present invention.

Claims

1. A GaN radiation-hardened driving circuit based on discrete devices, characterized in that, This includes a PWM output circuit, an isolation drive circuit, a drive enhancement circuit, and a level conversion circuit; The PWM output circuit is used to receive the power supply voltage feedback signal and output the drive control signal. Its output terminal can be selectively connected to the input terminal of the isolation drive circuit or the input terminal of the drive enhancement circuit. The isolation drive circuit is used to electrically isolate the drive control signal output by the PWM output circuit, and its output terminal is connected to the input terminal of the drive enhancement circuit. The drive enhancement circuit uses a totem pole structure composed of complementary transistors to amplify the current of the isolated drive control signal, and its output is connected to the input of the level conversion circuit. The level conversion circuit, through the cooperation of the RC charging and discharging structure and the voltage clamping structure, outputs a drive signal that is compatible with GaN power devices and can achieve high-level clamping on and negative-level shutdown.

2. The GaN radiation-hardened driving circuit based on discrete devices according to claim 1, characterized in that, The isolation drive circuit includes a DC blocking circuit, an isolation transformer T1, and a compensation circuit; The isolation transformer T1 includes primary windings T1-1 and T1-2 and secondary output windings T1-3 and T1-4; the primary winding terminal T1-1 is connected to the DC blocking circuit, and the secondary winding terminal T1-2 is connected to the primary ground; the secondary winding terminal T1-3 is connected to the compensation circuit, and the secondary winding terminal T1-4 is connected to the secondary ground. The DC blocking circuit includes a diode V1 and a DC blocking capacitor C1; the anode of the diode V1 is connected to the primary winding terminal T1-1, and the cathode is connected to the drive control signal point A; the DC blocking capacitor C1 is connected in parallel with the diode V1. The compensation circuit includes a compensation capacitor C2 and a bleeder resistor R1; one end of the compensation capacitor C2 is connected to the same terminal T1-3 of the secondary winding of the isolation transformer T1, and the other end is connected to the isolation drive signal point B; the bleeder resistor R1 is connected in parallel with the compensation capacitor C2.

3. The GaN radiation-hardened driving circuit based on discrete devices according to claim 1, characterized in that, The drive enhancement circuit includes voltage divider resistor R2, voltage divider resistor R3, secondary power supply Vs, transistor V2, and transistor V3; The voltage divider resistors R2 and R3 are connected in series; one end of the voltage divider resistor R2 is connected to the signal output terminal of the isolation drive circuit, and one end of the voltage divider resistor R3 is connected to the secondary output ground; the series junction of the voltage divider resistors R2 and R3 is connected to the base of both transistor V2 and transistor V3; the collector of transistor V2 is connected to the secondary power supply; the emitter of transistor V2 is connected to the emitter of transistor V3 and forms the signal output terminal of the drive enhancement circuit; the collector of transistor V3 is connected to the secondary output ground.

4. The GaN radiation-hardened driving circuit based on discrete devices according to claim 1, characterized in that, The level conversion circuit includes resistor R4, capacitor C3, diode V4, resistor R5, Zener diode V5, and Zener diode V6. The resistor R4 is connected in series with the capacitor C3; one end of the capacitor C3 is connected to the cathode of the diode V4 and the signal output terminal of the drive enhancement circuit; one end of the resistor R4 is connected to the anode of the diode V4, one end of the resistor R5 and the cathode of the Zener diode V5, forming a GaN drive signal output terminal; the anode of the Zener diode V5 is connected to the anode of the Zener diode V6; the other end of the resistor R5 and the cathode of the Zener diode V6 are both connected to the secondary output ground.

5. The GaN radiation-hardened driving circuit based on discrete devices according to claim 2, characterized in that, The diode V1 is a 1N4148 switching diode.

6. The GaN radiation-hardened driving circuit based on discrete devices according to claim 2, characterized in that, The primary and secondary windings of the isolation transformer T1 are configured according to a preset turns ratio to match the isolation drive voltage amplitude.

7. The GaN radiation-hardened driving circuit based on discrete devices according to claim 3, characterized in that, The transistor V2 is an NPN type JHGC3904 transistor; The transistor V3 is a PNP type JHGC3906 transistor.

8. The GaN radiation-hardened driving circuit based on discrete devices according to claim 3, characterized in that, The secondary power supply adopts an independent power supply or a bootstrap power supply method.

9. The GaN radiation-hardened driving circuit based on discrete devices according to claim 4, characterized in that, The diode V4 is a 1N4148 switching diode; Both Zener diodes V5 and V6 are BZ5230B Zener diodes.

10. The GaN radiation-hardened driving circuit based on discrete devices according to claim 1, characterized in that, When applied to a half-bridge topology, two sets of the GaN radiation-resistant drive circuits are configured. The signal output terminals of the two sets of GaN radiation-resistant drive circuits output two drive signals respectively to drive the upper and lower bridge arm GaN power devices of the half-bridge topology.

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