Experimental and Modeling Comparison of Different Damping Techniques to Suppress Switching Oscillations of SiC MOSFETs

摘要

The switching oscillations associated with the ultrafast switching characteristics of silicon carbide (SiC) MOSFETs seriously limit the potential of high frequency and high power density applications. To understand and mitigate this behavior, it is critical to analyze and compare different damping techniques for the oscillation suppression. This paper presents a simple RLC circuit model for SiC MOSFET turn-off switching oscillation, where the mitigation design guidelines are provided based on modeling analysis. The calculation, simulation and experimental results indicate that the switching oscillations can be properly controlled with the methods presented in this work. It is observed that the RC snubber and ferrite bead techniques offer more effective damping solution than the gate driver slowdown or extra gate resistor approaches.