A low surge voltage and fast speed gate driver for SiC MOSFET with switched capacitor circuit

Abstract

We propose a low surge voltage and fast speed gate driver with switched capacitor circuit for Silicon-Carbide (SiC) MOSFET. Because of the high switching frequency of SiC MOSFET, the surge voltage becomes a serious problem which cause a high switching loss and may break the SiC MOSFET. There is a trade-off between surge voltage and switching speed. It is hard to fulfill both of them at the same time by using conventional gate drivers. With the switched capacitor circuit, the proposed gate driver can reduce the surge voltage by 17.2% and the switching time by 8.4% at the turn-off transient. Compared to conventional gate drivers without the switched capacitor circuit, the proposed gate driver can generate negative gate-source voltage without any isolated power supply.