Evaluation of isolated gate driver for SiC MOSFETs

The SiC MOSFETs are finding their niche in 1 kV range, which is currently dominated by Si IGBTs. Thus, the frequencies of power converters could be increased remarkably and the power density could be higher. The gate driver for SiC MOSFET would affect the performance significantly, and a direct transplant of gate driver for Si MOSFET would not be reliable and efficient. This paper attempts to evaluate the design of gate driver for SiC MOSFETs. On the basis of studying the characteristics of SiC MOSFET, new requirements of gate driver for SiC MOSFETs are derived. A magnetic isolated gate driver is fabricated and experimental results based on an open loop BUCK circuit are presented. In order to optimize the performance of SiC MOSFETs, the gate drive loop must be carefully designed.