A highly reliable silicon carbide MOSFET half-bridge drive circuit

Abstract

This utility model discloses a highly reliable silicon carbide MOSFET half-bridge drive circuit, relating to the field of industrial and automotive drive circuit technology. It includes: an isolation circuit and a dual-channel VGS positive / negative voltage generation circuit. The isolation circuit is electrically connected to the dual-channel VGS positive / negative voltage generation circuit. The isolation circuit includes high-speed optocouplers PHT1 and PHT2. Pin 1 of the high-speed optocoupler PHT1 is electrically connected to resistor R12, capacitor C17, and one end of resistor R1. Pin 3 of the high-speed optocoupler PHT1 is electrically connected to one end of resistor R10. The technical problem this utility model aims to solve is to provide a highly reliable silicon carbide MOSFET half-bridge drive circuit, mainly addressing the issue of adjustable VGS control voltage for silicon carbide MOSFETs. It utilizes discrete components, resulting in a smaller size and better heat dissipation.

Description

Technical Field

[0001] This utility model relates to the field of industrial and automotive drive circuit technology, specifically to a silicon carbide MOSFET half-bridge drive circuit with high reliability. Background Technology

[0002] Silicon carbide MOSFETs, hailed as the "rising star" of the industry, are gradually becoming a market favorite due to their significant advantages such as low on-resistance, low switching losses, high switching frequency, and high operating junction temperature. Optimizing the drive circuit of silicon carbide MOSFETs is key to maximizing their high-frequency, high-temperature performance, and particular attention should be paid to protection circuit design. Because of the unique characteristics of silicon carbide MOSFETs, a thorough understanding and optimization of their drive circuits, including the design of protection circuits, is crucial to fully realizing their performance.

[0003] To fully utilize the performance of silicon carbide MOSFETs, the VGS voltage is typically controlled within the range of -5V to 20V, and fast rise and fall times are essential to ensure efficient switching performance. Stray inductance should be minimized during wiring to reduce electromagnetic interference and improve efficiency, while also incorporating protection circuitry. This is crucial for ensuring the stable and reliable operation of silicon carbide MOSFETs and maximizing their power density. Utility Model Content

[0004] The technical problem to be solved by this utility model is to provide a silicon carbide MOSFET half-bridge drive circuit with high reliability. The main problem is to solve the problem of adjustable VGS control voltage of silicon carbide MOSFET. It adopts discrete components, which are smaller in size and have better heat dissipation.

[0005] This utility model achieves its invention objective using the following technical solution:

[0006] A highly reliable silicon carbide MOSFET half-bridge drive circuit, characterized in that it includes: an isolation circuit and a dual-channel VGS positive / negative voltage generation circuit, wherein the isolation circuit is electrically connected to the dual-channel VGS positive / negative voltage generation circuit;

[0007] The isolation circuit includes high-speed optocoupler PHT1 and high-speed optocoupler PHT2; pin 1 of high-speed optocoupler PHT1 is electrically connected to resistor R12, capacitor C17 and one end of resistor R1; pin 3 of high-speed optocoupler PHT1 is electrically connected to one end of resistor R10; pin 3 of high-speed optocoupler PHT1 is electrically connected to the other end of resistor R12 and capacitor C17; pin 1 of high-speed optocoupler PHT2 is electrically connected to resistor R13, capacitor C18 and one end of resistor R3; pin 3 of high-speed optocoupler PHT2 is electrically connected to one end of resistor R11; pin 3 of high-speed optocoupler PHT2 is electrically connected to the other end of resistor R13 and capacitor C18.

[0008] The dual-channel VGS positive / negative voltage generation circuit includes: filter capacitors C4, C5, C6, C7, C15, C9, C10, C11, C16, C20, and C15; current-limiting resistors R2 and R6; Zener diodes VD4 and VD6; and rectifier diodes VD8 and VD9. Pin 4 of the high-speed optocoupler PHT1 is electrically connected to one end of capacitors C5, C7, C15, and C6, and one end of Zener diode VD4. Pin 4 of the high-speed optocoupler PHT1 is electrically connected to pin 1 of the rectifier VD8. Pin 6 of the high-speed optocoupler PHT1 is electrically connected to the other end of capacitors C5, C7, and C15. Pin 6 of the high-speed optocoupler PHT1 is electrically connected to pin 2 of the rectifier VD8. Pin 6 of the high-speed optocoupler PHT1 is electrically connected to one end of capacitor C4 and resistor R2. Pin 5 of the high-speed optocoupler PHT1 is electrically connected to pin 3 of the rectifier VD8.

[0009] Pin 4 of the high-speed optocoupler PHT2 is electrically connected to one end of capacitors C10, C20, C16, C11, and Zener diode VD6. Pin 4 of the high-speed optocoupler PHT2 is electrically connected to pin 1 of rectifier diode VD9. Pin 6 of the high-speed optocoupler PHT2 is electrically connected to the other end of capacitors C10, C20, and C16. Pin 6 of the high-speed optocoupler PHT2 is electrically connected to pin 2 of rectifier diode VD9. Pin 6 of the high-speed optocoupler PHT2 is electrically connected to one end of capacitor C9 and resistor R6. Pin 5 of the high-speed optocoupler PHT2 is electrically connected to pin 3 of rectifier diode VD9.

[0010] As a further limitation of this technical solution, it also includes a pulse transformer, which includes T1. One end of an electrical capacitor C2 is connected to pin 6 of the T1. The other end of the capacitor C2 is electrically connected to pin 3 of a rectifier VD2. Pin 1 of the rectifier VD2 is electrically connected to pin 4 of a high-speed optocoupler PHT1. Pin 2 of the rectifier VD2 and pin 7 of the T1 are respectively electrically connected to pin 6 of the high-speed optocoupler PHT1. One end of an electrical capacitor C8 is connected to pin 10 of the T1. The other end of the capacitor C8 is electrically connected to pin 3 of a rectifier VD5. Pin 1 of the rectifier VD5 and pin 9 of the T1 are respectively electrically connected to pin 4 of the high-speed optocoupler PHT2. Pin 2 of the rectifier VD5 is electrically connected to pin 6 of the high-speed optocoupler PHT2. Pin 4 of the T1 is electrically connected to capacitor C12.

[0011] As a further limitation of this technical solution, it also includes a transformer primary-side drive circuit, which includes a chip U2. Pin 1 of the chip U2 is electrically connected to one end of resistor R15. Pins 2 and 4 of the chip U2 are electrically connected to one end of resistor R4 and resistor R14, respectively. Pins 5 and 7 of the chip U2 are electrically connected to pin 5 of the T1, pin 6 of the chip U2 is electrically connected to capacitor C14, and pin 8 of the chip U2 is electrically connected to resistor R16.

[0012] As a further limitation of this technical solution, it also includes an oscillation circuit, which includes a chip U1. Pin 4 of the chip U1 is electrically connected to one end of resistor R5 and capacitor C21. Pin 6 of the chip U1 is electrically connected to the other end of resistor R4. Pin 7 of the chip U1 is electrically connected to one end of capacitor C22. Pin 7 of the chip U1 is electrically connected to one end of capacitor C3 and the other end of resistor R5.

[0013] As a further limitation of this technical solution, it also includes an LDO step-down circuit, which includes filter capacitors C13, C19, and C1, an integrated circuit LM317K, diodes VD12 and VD13, and feedback resistors R7 and R8. Pin 1 of the integrated circuit LM317K is electrically connected to one end of resistor R8, capacitor C19, and resistor R7. Pin 2 of the integrated circuit LM317K is electrically connected to one end of capacitor C1 and the other end of resistor R7. Pin 2 of the integrated circuit LM317K is electrically connected to pin 1 of diode VD13. Pin 3 of diode VD13 is electrically connected to pin 1 of diode VD12. Pin 3 of diode VD12, one end of capacitor C13, and pin 3 of integrated circuit LM317K are respectively electrically connected to pin 1 of connector XS3.

[0014] As a further limitation of this technical solution, the other end of resistor R1 is electrically connected to pin 6 of connector XS3, the other end of resistor R10 is electrically connected to pin 5 of connector XS3, the other end of resistor R3 is electrically connected to pin 4 of connector XS3, the other end of resistor R11 is electrically connected to pin 3 of connector XS3, pin 5 of high-speed optocoupler PHT1 is electrically connected to pins 1 and 2 of connector XS2, the other ends of capacitor C4, resistor R2, Zener diode VD4 and capacitor C6 are respectively electrically connected to pins 3 and 4 of connector XS2, pin 5 of high-speed optocoupler PHT2 is electrically connected to pins 3 and 4 of connector XS1, and the other ends of capacitor C9, resistor R6, Zener diode VD6 and capacitor C11 are respectively electrically connected to pins 1 and 2 of connector XS1.

[0015] Compared with related technologies, the silicon carbide MOSFET half-bridge drive circuit with high reliability provided by this utility model has the following beneficial effects:

[0016] (1) The main solution is to address the issue of adjustable VGS control voltage in silicon carbide MOSFETs. Discrete components are used, resulting in smaller size and better heat dissipation.

[0017] (2) The silicon carbide MOSFET half-bridge drive circuit design uses pulse transformer T1 to achieve power supply isolation and high-speed optocouplers PHT1 and PHT2 to achieve drive signal isolation. The dual isolation circuit improves the reliability and safety of silicon carbide MOSFET operation. Attached Figure Description

[0018] Figure 1 The circuit principle of this utility model Figure 1 .

[0019] Figure 2 The circuit principle of this utility model Figure 2 .

[0020] Figure 3 This is a functional block diagram of the silicon carbide MOS half-bridge driver of this utility model.

[0021] Figure 4 This is a waveform diagram of the silicon carbide MOS transistor driving according to this utility model. Detailed Implementation

[0022] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0023] A highly reliable silicon carbide MOSFET half-bridge drive circuit includes: an isolation circuit and a dual-channel VGS positive / negative voltage generation circuit. The isolation circuit is electrically connected to the dual-channel VGS positive / negative voltage generation circuit. The isolation circuit isolates the drive signals of the dual silicon carbide MOSFETs and includes two identical isolation circuits for the upper and lower MOSFETs. The isolation circuit includes high-speed optocouplers PHT1 and PHT2. Pin 1 of the high-speed optocoupler PHT1 is electrically connected to resistor R12, capacitor C17, and one end of resistor R1. Pin 3 of the high-speed optocoupler PHT1 is electrically connected to one end of resistor R10. Pin 3 of the high-speed optocoupler PHT1 is also electrically connected to resistor R12 and capacitor C17. At the other end of capacitor C17, pin 1 of the high-speed optocoupler PHT2 is electrically connected to one end of resistor R13, capacitor C18, and resistor R3. Pin 3 of the high-speed optocoupler PHT2 is electrically connected to one end of resistor R11. Pin 3 of the high-speed optocoupler PHT2 is electrically connected to the other end of resistor R13 and capacitor C18. The working logic of the upper transistor is as follows: the input signal is stepped down by resistors R1, R10, and R12, and high-frequency interference signals are filtered out by absorption capacitor C17. The infrared LED of the primary side of the optocoupler is driven. The infrared light is transmitted to the phototransistor of the secondary side. The secondary side of the optocoupler is powered by the positive and negative voltage generated by the VGS positive and negative voltage generation circuit. Finally, the signal required for driving the silicon carbide MOS half-bridge is output.The dual-channel VGS positive / negative voltage generation circuit, in conjunction with a transformer, provides the +18V and -2.7V drive voltages required by the silicon carbide half-bridge MOS. Similar to the isolation circuit, it has two paths: one for the upper transistor and one for the lower transistor. The dual-channel VGS positive / negative voltage generation circuit includes: filter capacitors C4, C5, C6, C7, C15, C9, C10, C11, C16, C20, and C15; current-limiting resistors R2 and R6; Zener diodes VD4 and VD6; and rectifier diode VD8. Pin 4 of the high-speed optocoupler PHT1 is electrically connected to one end of capacitors C5, C7, C15, C6, and Zener diode VD4. Pin 4 of the high-speed optocoupler PHT1 is electrically connected to pin 1 of rectifier diode VD8. Pin 6 of the high-speed optocoupler PHT1 is electrically connected to the other end of capacitors C5, C7, and C15. Pin 6 of the high-speed optocoupler PHT1 is electrically connected to... Pin 2 of the rectifier VD8; pin 6 of the high-speed optocoupler PHT1 is electrically connected to one end of the capacitor C4 and the resistor R2; pin 5 of the high-speed optocoupler PHT1 is electrically connected to pin 3 of the rectifier VD8; pin 4 of the high-speed optocoupler PHT2 is electrically connected to one end of the capacitors C10, C20, C16, C11, and the Zener diode VD6; pin 4 of the high-speed optocoupler PHT2 is electrically connected to pin 1 of the rectifier VD9; pin 6 of the high-speed optocoupler PHT2 is electrically connected to the other end of the capacitors C10, C20, and C16; pin 6 of the high-speed optocoupler PHT2 is electrically connected to pin 2 of the rectifier VD9; pin 6 of the high-speed optocoupler PHT2 is electrically connected to one end of the capacitor C9 and the resistor R6; pin 5 of the high-speed optocoupler PHT2 is electrically connected to pin 3 of the rectifier VD9.

[0024] VD8 and VD9 rectify the two secondary windings of the transformer and, together with the filter capacitor, obtain a positive voltage of 18V. VD4 and VD6 are Zener diodes, which, together with the current-limiting resistors R2 and R6 and the filter capacitor, provide a stable negative voltage for the drive circuit. R2 and R6 are selected as BZT52C2V7, and the resulting negative voltage is -2.7V.

[0025] It also includes a pulse transformer, which is responsible for isolation transformation. The core material is PC95, with one primary winding and two secondary windings. The turn ratio of the primary and secondary windings of the transformer is 14:14:14. In the circuit, C12 is the DC blocking capacitor of the primary winding, and C2 and C8 are the DC blocking capacitors of the secondary windings of the upper and lower transistors, respectively. The pulse transformer includes T1. Pin 6 of T1 is connected to one end of capacitor C2. The other end of capacitor C2 is electrically connected to pin 3 of rectifier VD2. Pin 1 of rectifier VD2 is electrically connected to pin 4 of high-speed optocoupler PHT1. Pin 2 of rectifier VD2 and pin 7 of T1 are electrically connected to pin 6 of high-speed optocoupler PHT1. Pin 10 of T1 is connected to one end of capacitor C8. The other end of capacitor C8 is electrically connected to pin 3 of rectifier VD5. Pin 1 of rectifier VD5 and pin 9 of T1 are electrically connected to pin 4 of high-speed optocoupler PHT2. Pin 2 of rectifier VD5 is electrically connected to pin 6 of high-speed optocoupler PHT2. Pin 4 of T1 is electrically connected to capacitor C12.

[0026] It also includes a transformer primary-side drive circuit, which is responsible for driving the primary coil of the pulse transformer. The circuit includes: enable pull-up resistors R15 and R16; energy storage filter capacitor C14; integrated circuit U2; and drive voltage divider resistors R4 and R14. This part of the circuit amplifies the 126kHz drive signal from the oscillation circuit and drives the transformer. The transformer primary-side drive circuit includes chip U2. Pin 1 of chip U2 is electrically connected to one end of resistor R15. Pins 2 and 4 of chip U2 are electrically connected to one end of resistors R4 and R14, respectively. Pins 5 and 7 of chip U2 are electrically connected to pin 5 of T1, pin 6 of chip U2 is electrically connected to capacitor C14, and pin 8 of chip U2 is electrically connected to resistor R16.

[0027] It also includes an oscillation circuit, which provides a drive signal to the primary drive circuit of the transformer. The circuit includes: filter capacitors C3 and C22, integrated circuit U1, and oscillation resistors and capacitors C21 and R5. The oscillation frequency of the oscillation circuit is: F = 1.72 / (2 * R5 * C21) = 126kHz. Adjusting C21 and R5 can change the output frequency. Based on the characteristics of the transformer core, a frequency of 126kHz is chosen. The oscillation circuit includes chip U1. Pin 4 of chip U1 is electrically connected to one end of resistor R5 and capacitor C21; pin 6 of chip U1 is electrically connected to the other end of resistor R4; pin 7 of chip U1 is electrically connected to one end of capacitor C22; and pin 8 of chip U1 is electrically connected to one end of capacitor C3 and the other end of resistor R5.

[0028] It also includes an LDO step-down circuit, which adjusts the input 24V voltage to the positive voltage required for driving the silicon carbide MOSFET and supplies power to the oscillation circuit and the primary-side drive circuit of the transformer. The LDO step-down circuit includes filter capacitors C13, C19, and C1, an integrated circuit LM317K, diodes VD12 and VD13, and feedback resistors R7 and R8. Pin 1 of the integrated circuit LM317K is electrically connected to one end of resistor R8, capacitor C19, and resistor R7. Pin 2 of the integrated circuit LM317K is electrically connected to one end of capacitor C1 and the other end of resistor R7. Pin 2 of the integrated circuit LM317K is electrically connected to pin 1 of diode VD13. Pin 3 of diode VD13 is electrically connected to pin 1 of diode VD12. Pin 3 of diode VD12, one end of capacitor C13, and pin 3 of integrated circuit LM317K are respectively electrically connected to pin 1 of connector XS3.

[0029] The output voltage of the LDO step-down circuit is: VCC = 1.25V * (R7 + R8) / R7 = 15V. Adjusting R8 can change the output voltage, thereby changing the positive voltage required to drive the silicon carbide MOSFET.

[0030] The other end of resistor R1 is electrically connected to pin 6 of connector XS3, the other end of resistor R10 is electrically connected to pin 5 of connector XS3, the other end of resistor R3 is electrically connected to pin 4 of connector XS3, the other end of resistor R11 is electrically connected to pin 3 of connector XS3, pin 5 of high-speed optocoupler PHT1 is electrically connected to pins 1 and 2 of connector XS2, the other ends of capacitor C4, resistor R2, Zener diode VD4 and capacitor C6 are electrically connected to pins 3 and 4 of connector XS2 respectively, pin 5 of high-speed optocoupler PHT2 is electrically connected to pins 3 and 4 of connector XS1, and the other ends of capacitor C9, resistor R6, Zener diode VD6 and capacitor C11 are electrically connected to pins 1 and 2 of connector XS1 respectively.

[0031] The working principle of the silicon carbide MOSFET half-bridge drive circuit with high reliability provided by this utility model is as follows:

[0032] The 24V voltage is reduced to a stable 18V voltage by the LDO step-down circuit. This 18V voltage powers the oscillation circuit and the primary drive circuit of the transformer. After isolation by the pulse transformer, the dual-channel VGS positive and negative voltage generation circuits generate dual-channel 18V and dual-channel -2.7V voltages.

[0033] The isolation circuit receives dual TTL level pulse signals as input and outputs 18V and -2.7V isolation voltages to obtain the VGS signal required for driving the half-bridge silicon carbide MOSFET. We can change the positive 18V voltage by altering R8 in the LDO step-down circuit, and we can also change the negative -2.7V voltage by changing the types of Zener diodes VD4 and VD6, thus adapting to the driving requirements of various silicon carbide MOSFETs both domestically and internationally.

[0034] The above description is merely an embodiment of this utility model and does not limit the patent scope of this utility model. Any equivalent structural or procedural transformations made based on the content of this utility model specification and drawings, or direct or indirect applications in other related technical fields, are similarly included within the patent protection scope of this utility model.

Claims

1. A highly reliable silicon carbide MOSFET half-bridge drive circuit, characterized in that, include: An isolation circuit and a dual-channel VGS positive / negative voltage generation circuit are provided, wherein the isolation circuit is electrically connected to the dual-channel VGS positive / negative voltage generation circuit. The isolation circuit includes high-speed optocouplers PHT1 and PHT2; pin 1 of high-speed optocoupler PHT1 is electrically connected to resistor R12, capacitor C17, and one end of resistor R1; pin 3 of high-speed optocoupler PHT1 is electrically connected to one end of resistor R10; pin 3 of high-speed optocoupler PHT1 is electrically connected to the other end of resistor R12 and capacitor C17; pin 1 of high-speed optocoupler PHT2 is electrically connected to resistor R13, capacitor C18, and one end of resistor R3; pin 3 of high-speed optocoupler PHT2 is electrically connected to one end of resistor R11; pin 3 of high-speed optocoupler PHT2 is electrically connected to the other end of resistor R13 and capacitor C18.

2. The silicon carbide MOSFET half bridge drive circuit with high reliability according to claim 1, characterized by: The dual-channel VGS positive / negative voltage generation circuit includes: filter capacitors C4, C5, C6, C7, C15, C9, C10, C11, C16, C20, and C15; current-limiting resistors R2 and R6; Zener diodes VD4 and VD6; and rectifier diodes VD8 and VD9. Pin 4 of the high-speed optocoupler PHT1 is electrically connected to one end of capacitors C5, C7, C15, and C6, and one end of Zener diode VD4. Pin 4 of the high-speed optocoupler PHT1 is electrically connected to pin 1 of the rectifier VD8. Pin 6 of the high-speed optocoupler PHT1 is electrically connected to the other end of capacitors C5, C7, and C15. Pin 6 of the high-speed optocoupler PHT1 is electrically connected to pin 2 of the rectifier VD8. Pin 6 of the high-speed optocoupler PHT1 is electrically connected to one end of capacitor C4 and resistor R2. Pin 5 of the high-speed optocoupler PHT1 is electrically connected to pin 3 of the rectifier VD8. Pin 4 of the high-speed optocoupler PHT2 is electrically connected to one end of capacitors C10, C20, C16, C11, and Zener diode VD6. Pin 4 of the high-speed optocoupler PHT2 is electrically connected to pin 1 of rectifier diode VD9. Pin 6 of the high-speed optocoupler PHT2 is electrically connected to the other end of capacitors C10, C20, and C16. Pin 6 of the high-speed optocoupler PHT2 is electrically connected to pin 2 of rectifier diode VD9. Pin 6 of the high-speed optocoupler PHT2 is electrically connected to one end of capacitor C9 and resistor R6. Pin 5 of the high-speed optocoupler PHT2 is electrically connected to pin 3 of rectifier diode VD9.

3. The SiC MOSFET half bridge drive circuit with high reliability according to claim 2, characterized in that: It also includes a pulse transformer, which includes T1. Pin 6 of T1 is connected to one end of capacitor C2. The other end of capacitor C2 is electrically connected to pin 3 of rectifier VD2. Pin 1 of rectifier VD2 is electrically connected to pin 4 of high-speed optocoupler PHT1. Pin 2 of rectifier VD2 and pin 7 of T1 are electrically connected to pin 6 of high-speed optocoupler PHT1. Pin 10 of T1 is connected to one end of capacitor C8. The other end of capacitor C8 is electrically connected to pin 3 of rectifier VD5. Pin 1 of rectifier VD5 and pin 9 of T1 are electrically connected to pin 4 of high-speed optocoupler PHT2. Pin 2 of rectifier VD5 is electrically connected to pin 6 of high-speed optocoupler PHT2. Pin 4 of T1 is electrically connected to capacitor C12.

4. The silicon carbide MOSFET half bridge drive circuit with high reliability according to claim 3, characterized by: It also includes a transformer primary-side drive circuit, which includes a chip U2. Pin 1 of the chip U2 is electrically connected to one end of resistor R15. Pins 2 and 4 of the chip U2 are electrically connected to one end of resistors R4 and R14, respectively. Pins 5 and 7 of the chip U2 are electrically connected to pin 5 of the T1, pin 6 of the chip U2 is electrically connected to capacitor C14, and pin 8 of the chip U2 is electrically connected to resistor R16.

5. The silicon carbide MOSFET half bridge drive circuit with high reliability according to claim 4, characterized by: It also includes an oscillation circuit, which includes a chip U1. Pin 4 of the chip U1 is electrically connected to one end of a resistor R5 and a capacitor C21. Pin 6 of the chip U1 is electrically connected to the other end of the resistor R4. Pin 7 of the chip U1 is electrically connected to one end of a capacitor C22. Pin 7 of the chip U1 is electrically connected to one end of a capacitor C3 and the other end of the resistor R5.

6. The SiC MOSFET half bridge drive circuit with high reliability according to claim 2, characterized by: It also includes an LDO step-down circuit, which includes filter capacitors C13, C19, and C1, an integrated circuit LM317K, diodes VD12 and VD13, and feedback resistors R7 and R8. Pin 1 of the integrated circuit LM317K is electrically connected to one end of resistor R8, capacitor C19, and resistor R7. Pin 2 of the integrated circuit LM317K is electrically connected to one end of capacitor C1 and the other end of resistor R7. Pin 2 of the integrated circuit LM317K is electrically connected to pin 1 of diode VD13. Pin 3 of diode VD13 is electrically connected to pin 1 of diode VD12. Pin 3 of diode VD12, one end of capacitor C13, and pin 3 of integrated circuit LM317K are respectively electrically connected to pin 1 of connector XS3.

7. The SiC MOSFET half bridge drive circuit with high reliability according to claim 6, characterized by: The other end of resistor R1 is electrically connected to pin 6 of connector XS3, the other end of resistor R10 is electrically connected to pin 5 of connector XS3, the other end of resistor R3 is electrically connected to pin 4 of connector XS3, the other end of resistor R11 is electrically connected to pin 3 of connector XS3, pin 5 of high-speed optocoupler PHT1 is electrically connected to pins 1 and 2 of connector XS2, the other ends of capacitor C4, resistor R2, Zener diode VD4 and capacitor C6 are electrically connected to pins 3 and 4 of connector XS2 respectively, pin 5 of high-speed optocoupler PHT2 is electrically connected to pins 3 and 4 of connector XS1, and the other ends of capacitor C9, resistor R6, Zener diode VD6 and capacitor C11 are electrically connected to pins 1 and 2 of connector XS1 respectively.

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