The Method to Evaluate the SOA of Drain-Source Voltage for SiC MOSFET

Silicon Carbide (SiC) MOSFETs have superior material characteristics, including high switching frequency and high-temperature. They are widely used in high-density power electronic system. In order to access its full potential, especially in high-frequency and high-temperature applications, in this paper, a method to evaluate the safe operating area (SOA)defined by the drain-source voltage peak during switching transient is proposed. Firstly, theoretical treatment on the switching transient and the failure mechanism during turnoff transient for SiC MOSFET is conducted. Then, the temperature dependency of the drain-source overshoot is derived. Finally, double pulse test platform is designed for different temperature conditions, and the SOA defined by the drain-source voltage overshoot has been investigated. The conclusion of this paper implies that the device can be operated on a higher switching speed under high temperature conditions, which will provide some guidance on accessing the full advantage of the high frequency and high temperature characteristics of SiC MOSFET.