Investigation on inherently safe gate drive techniques for normally-on wide bandgap power semiconductor switching devices

Normally-on wide bandgap power semiconductor devices such as SiC JFET or GaN HFET demonstrate great promise for future power electronics applications, but suffer from power bus shoot-through concerns. This paper investigates new gate drive techniques to make the normally-on WBG devices inherently safe against potential power bus shoot-through failures. A fast-acting startup lockup protection circuit is proposed to derive power directly from the DC bus and generate a negative voltage to hold the WBG device in OFF mode. Simulation and experiment results show that the startup lockup source could generate -12 V voltage within a few mus.