Characterization and Modeling of a SiC MOSFET's Turn-Off Overvoltage

摘要

The overvoltage during hard switching limits the full utilization of devices due to higher blocking voltage requirement. The faster switching speed of a SiC MOSFET worsens the trade-off, and the understanding of the overvoltage's mechanism is crucial for better utilization. In this work, experimental characterizations on the influence of circuit parasitic parameters and gate resistances on overvoltage were performed. Furthermore, a SPICE-based device behavioral model is built and found capable of accurately predicting the overvoltage. The same method could be applied to device rating selection in converter design.