A Revisit to Resonant Gate Driver and a Hybrid Driver to Improve EMI vs. loss Tradeoff for SiC MOSFET

Abstract:
In the past two decades, numerous active gate drivers were designed or invented to achieve ‘defined switching behavior’ of Si IGBT. The tradeoff between switching loss and electromagnetic interference (EMI) has always been a challenge. With SiC MOSFET having switching speed (drain voltage VDS or drain current ID transient) that could be tenfold ore more compared with Si IGBT, it is not feasible to use closed-loop active gate driver to control EMI generated from SiC MOSFET. In this paper, the concept of using high gate impedance and open-loop driver to control EMI is first discussed. Subsequently, a hybrid driver is invented to further reduce switching loss in addition to EMI. Simulation results confirm that tradeoff between switching loss and EMI can be improved for SiC MOSFET.