A Study on Suppressing Surge Voltage of SiC MOSFET Using Digital Active Gate Driver

Wide-bandgap power devices are expected to open the way to achieve an integrated power circuit with higher power density. However, the large surge voltage and ringing caused by the fast switching will lose the reliability of the device and increase electromagnetic interference (EMI) problems. In this paper, we propose a digital active gate driver for SiC power MOSFETs. Active gate drive is one of the solutions to achieve high-frequency switching without the above drawbacks. The digital active gate driver is designed based on the architecture of a digital-to-analog converter. The gate-source voltage waveform of the MOSFET is adjusted flexibly with a multi-bit gate signal sequence. It is experimentally verified that the proposed driver suppresses the surge voltage of SiC MOSFET during turn-off.