Active Gate Drive Circuit with Auxiliary Drive Branch for SiC MOSFET

Silicon Carbide (SiC) MOSFET has a fast switching speed and is sensitive to parasitic parameters, which is easy to cause higher turn-off transient overshoot voltage, which directly threatens the stability and safety of SiC MOSFET devices and causes excessive switching losses. To suppress voltage and current surges and oscillations during switching, this paper proposes an active drive circuit with an auxiliary gate drive branch. By adjusting the switching time of the auxiliary switching tube of the auxiliary driving branch, the gate current can be reduced in the sensitive stage of overshoot and oscillation, and the gate current can be increased in the non-sensitive stage to reduce the switching loss. A SiC MOSFET drive circuit simulation and experimental test platform is built to verify the effectiveness of the drive circuit. The experimental results show that the proposed SiC MOSFET active gate drive circuit reduces the gate current overshoot by 48.5% during the turn-on process, and reduces the drain-source voltage overshoot by 52.4% during the turn-off process.