An Integrated Multi-level Active Gate Driver for SiC Power Modules

Abstract

Silicon carbide (SiC) power devices have advantages, such as excellent breakdown field strength, heat dissipation characteristics, and electron saturation velocity. Thus, the SiC-based power semiconductors can operate at higher switching frequencies with higher voltages and better stability than conventional silicon (Si) devices resulting in a high-power density. However, the high switching slew rate of SiC devices 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. Therefore, this paper proposes an integrated multi-level active gate driver (AGD) to solve the EMI noise issues effectively and flexibly. The proposed AGD controls the turn-on switching slew rate through controllable AGD voltages in real-time. The leg controller generates multi-level drive voltages 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 accurately control the turn-on switching slew rates under various system operational conditions. The proposed AGD method has been verified through experimental results.