High Voltage Output Characteristics and Short Circuit Robustness of HV SiC MOSFETs

Abstract

The short circuit characteristics of the recently developed high voltage (HV) SiC MOSFETs are essential to ensure the proper functioning of the power converters during the short circuit fault conditions. The short circuit failure time can be estimated using the HV output characteristics of the MOSFETs with reasonable assumptions. The HV output characteristics of the 3.3 kV, 6.5 kV, and 10 kV SiC MOSFETs, developed by Wolfspeed, are measured for the first time. The estimated short circuit failure time is 3.5 μs, 7.4 μs and 8.1 μs for the 3.3 kV, 6.5 kV, and 10 kV SiC MOSFETs, respectively at the gate bias of 15 V. The analytical results are closely matching with the experimental short circuit failure results of the 6.5 kV SiC MOSFET. The short circuit robustness of the single 6.5 kV SiC MOSFET is found to be superior to the two series-connected 3.3 kV SiC MOSFETs.