Normally open SiC JFET drive circuit having self protection function

The invention solves technical problems and provides a normally open SiC JFET (Junction Field-effect Transistor) drive circuit having a self protection function. When bridge arm direct connection is caused by drive power supply failure, an auxiliary capacitor in a self protection circuit discharges. A negative switching-off voltage is applied to a grid-source electrode of a SiC JFET to force the SiC JFET to be switched off quickly, so that a controller can cut power supply within a safe time period and the protection aim is achieved. Besides, drive output adopts an RCD structure, so that SiC JFET high speed switching-on and switching-off can be realized and grid voltage oscillation caused by Miller current can be inhibited. The normally open SiC JFET drive circuit is suitable for a high-speed bridge arm structure. 本发明所解决的技术问题在于提供种具有自保护功能的常通型SiC JFET驱动电路。当驱动电源故障导致桥臂直通时，自保护电路中辅助电容放电，在SiC JFET栅源极施加个负向关断电压，迫使其快速关断，使控制器能够在安全时间范围内切断电源，达到保护的目的。另外，驱动输出采用RCD结构，既可以实现SiC JFET高速开关，又可以抑制密勒电流引起的栅极电压振荡，是种适用于高速桥臂结构的常通型SiC JF