SiC MOSFET Short-Circuit Protection: a Faster Soft Shut Down Method for Gate Drivers

Abstract:
Standard short-circuit protection features implemented in gate drivers are often calibrated for IGBT technology. However, the increase in switching slope of the wide-band Gap semiconductors and their lower reliability/maturity is a challenge for securing these new devices against SC events. Decreasing the delays in protection circuits is hence required to secure the operation of high power SiC MOSFETs. This paper presents an Advanced Soft Shut Down method with a reaction delay of 400ns after detection of a 650nH SC. The principle was demonstrated on a 1.2kV SiC module with a bipolar buffer stage based gate driver.