Influence of the Inverter Dead-time on the Reverse Recovery Characteristics of 3.3-kV SiC MOSFETs and JBSFETs

The switching behavior of the high voltage (HV) SiC MOSFETs is superior to that of HV silicon IGBTs. In medium voltage high switching frequency power conversion applications, the reverse recovery effect of the body diode results in large switching losses. In this work, the reverse recovery behavior of the body diode of the recently developed 3.3 kV SiC MOSFETs is investigated at varying junction temperature and current levels. Two solutions are proposed to reduce the reverse recovery losses - by using the optimized dead-time and by integrating Schottky diode in the MOSFETs. The experimental results validate the proposed solutions. A device physics-based numerical model is used to explain the improvement in the body diode reverse recovery characteristics at the smaller dead-time.