Design and experiments of isolated gate driver using discrete devices for silicon carbide MOSFET

Abstract

The high temperature (HT) characteristics of silicon carbide (SiC) devices enable power electronic converters to operate at higher ambient temperature, and the importance of HT isolated gate drivers is becoming increasingly significant. Compared with the complex silicon on insulator (SOI) HT chips and normal silicon (Si) ICs, the Si‐based discrete devices can well balance the temperature capability and design cost. A feasible isolated gate driver design method is proposed in this paper by using discrete MOSFETs, discrete BJTs and other passive components with consideration of cost and can be with less leakage current than normal integrated circuits. The function of gate driver includes signal isolation and signal amplification. In the signal isolation part, a CMOS‐based isolation circuit is proposed with its merits. In the signal amplification part, normal topologies are improved to get better efficiency and high‐speed capability. SiC power module‐based double pulse test is used to verify the switching performance, and experiments are done to verify the continuous operating capability. The main factors which affect the performance of the proposed isolated gate driver are summarized. This technology provides a novel solution for SiC MOSFET gate driver in HT environment.