Short Circuit Protection Investigation on Wide Bandgap Devices

Power management is one of the biggest issues of modern society because of the growing need of electrical power in our daily lives. The most important figure of merit of power converters is the efficiency, a measure of how ideal they are. For the sake of enhancing the efficiency of any power converter, new power transistors technology has been developed and improved in recent years as SiC and GaN. The more efficient these devices are, the lower their short circuit withstand time and reliability is, though. IGBTs had a short circuit withstand time in the order of 10us, SiC in the order of 1us, GaN short circuit withstand time is still not known exactly but is even shorter. This means that more care needs to be taken for the design of short circuit protection circuits. Little established methodologies exist to reliably protect GaN transistors in commercial drivers. This project aims to explore both d-mode and e-mode GaN reliability by measuring their degradation, through unrecoverable parameter drift detection, after they experienced a set of short circuit pulses, in different circuit state conditions.