An Active Gate Driver for Suppressing the Current Oscillation of SiC MOSFET

Due to the superior material properties, silicon carbide MOSFETs have been widely used in high-speed and high-frequency applications. The current oscillation, overshoot, and EMI problems caused by higher switching speed are more serious. To solve the problems, the mechanism of the current oscillation during the turn-on process was analyzed. An active gate driver to suppress the oscillation was proposed based on the analysis. During the current rise time, the gate-source voltage is pulled-off to control the current rise rate, which can suppress the overshoot and oscillation. The feasibility was verified by simulation. Besides, a double pulse test was carried out to evaluate the method. The experiment results show that compared to the traditional gate driver, the active gate driver can suppress the current overshoot and high-frequency components with a little increase in losses. Above all, the proposed active gate driver can effectively suppress current oscillations.