An Integrated Active Gate Driver for Half-bridge SiC MOSFET Power Modules

Abstract

Silicon carbide (SiC) power devices have excellent breakdown field strength, heat dissipation characteristics, and electron saturation velocity. The SiC-based power semi-conductors can operate at higher switching frequencies with higher voltages and better stability than conventional silicon (Si) devices. Therefore, SiC-based power converters can achieve a high-power density. However, the high switching slew rate of SiC devices accompanied by high-speed switching operations can cause EMI noise problems. Conventional gate drivers cannot effectively control such EMI noise issues, including passive and active gate driver techniques under various system environments. This paper proposes an integrated active gate driver (AGD) to solve the EMI noise issues more effectively and flexibly. The proposed AGD controls the switching slew rate through controllable AGD voltages in real-time according to the system variables that can significantly affect switching characteristics such as the DC BUS voltage, output current, and device temperature. The proposed AGD enables switching devices to control the switching speed accurately under various system operational conditions. The proposed AGD method has been verified through experimental results.