A Gate Voltage Clamping Method to Improve the Short-Circuit Characteristic of SiC MOSFET

The Short-Circuit Withstand Time (SCWT) of SiC MOSFET is generally considered as around 3μs at rated condition. This is considered to be much shorter than its counterpart Si-IGBT, which also limits its popularity to some extent. In this paper, the Gate Voltage Clamping (GVC) method is proposed to extend the SCWT of SiC MOSFET to l0μs by clamping the gate driving voltage. The proposed GVC method does not interfere with the static characteristics of SiC MOSFET, meanwhile using as few components as possible. To calibrate the proposed method, a whole set of destructive tests under different gate driving voltages are made to extract the suitable clamping target value for the GVC circuit. It is experimentally validated that the proposed GVC method can extend the SCWT of DUT to l0μs, by using two types of simulated short-circuit (SC) failures.