Current controlled active gate driver for 1200V SiC MOSFET

1200V SiC MOSFETs have superior characteristics compared to silicon (Si) IGBTs. However due to parasitic inductances in the converter layout, one to one replacement of Si IGBT with SiC MOSFET may result in higher overshoot in the device voltage and current. Active gate driving mechanism can control these unwanted stresses on the device without compromising its switching speed. The limited bandwidth of OP-AMP used in a conventional closed loop active gate driver poses a major hindrance to drive fast switching SiC MOSFET. To address this issue a new current controlled Active Gate Driver mechanism is proposed. The proposed AGD can be realized with cheaper electronic components with sufficient bandwidth to drive a SiC MOSFET. The proposed technique ensures better controllability on the device by directly controlling the injected gate current. The proposed AGD has been experimentally verified in a double pulse test set up with a 1200 V, 35 A SiC MOSFET (ROHM make: SCH2080KE).