A Novel Gate Driver of SiC MOSFET for Crosstalk Suppression in Bridge Configuration

摘要

Silicon carbide (SiC) MOSFETs have the advantages of fast switching speed and low on-state resistance, which are gradually used in electric vehicle (EV) charger. However, due to the internal parasitic parameters of SiC MOSFET, crosstalk problem can be easily caused when it is used in the bridge configuration. In this paper, a gate driver is proposed for SiC MOSFET to suppress the positive and negative crosstalk. By applying a passive transistor with a serially capacitor and a diode connected in reverse with the emitter of the transistor, the proposed driver can suppress positive and negative crosstalk spikes effectively without affecting the high switching speed of SiC MOSFET. Meanwhile, the proposed driver can also generate negative turn-off voltage itself. Firstly, the principle of crosstalk generation is explained, and the influence of different driving resistances on the value of crosstalk spike is analyzed. Then, the principle of the proposed driver is described and the parameter design is deduced. Finally, simulation in LTspice is performed to verify the effectiveness of the proposed driver.