Turn-on loss is the dominant part of the switching loss for SiC MOSFETs in hard switching. The turn-on loss is difficult to reduce with conventional voltage source gate drives (VSG) because of limited gate voltage rating and large internal gate resistance of SiC MOSFETs. A charge pump gate drive (CPG) is presented in this paper that can help improve the switching speed and reduce turn-on loss. By pre-charging the charge-storage capacitor in the gate drive with a charge pump circuit, the gate drive output voltage is pumped up to provide higher gate current during the turn-on transient. Moreover, due to the charge transfer from the charge-storage capacitor to the MOSFET gate capacitance, the pumped output voltage can naturally drop back to a normal value, avoiding gate overcharging. The structure of the gate drive is simple, and no additional control is needed. The proposed CPG is verified with double pulse tests. The turn-on switching time is reduced by 67.4% at full load condition with the proposed CPG.
