This paper presents a new desaturation protection method for silicon carbide (SiC) power MOSFETs. The proposed method provides an extra charging loop for the fault detection part of desaturation protection circuit by utilizing the difference of drain-source voltage between fault and normal condition. It can effectively reduce the overall response time and the acceleration is partly self-adaptive according to the operating voltage, without compromising its noise immunity. Thus, it achieves a fast and stable protection for SiC devices. The proposed circuit has been simulated and the results verify its performance initially by comparing with conventional desaturation protection circuit. Meanwhile, the relevant theoretical analysis is presented to guide circuit design.

desaturation protection, SiC MOSFET, self-adaptive blanking time