Experimental Validation of CT-Snubber for Multichip SiC MOSFET Power Module

Recently, a "CT-snubber" circuit was shown to enable high bandwidth current measurements and ringing suppression in silicon carbide MOSFETs multi-chip power modules. Preliminary designs increased damping but also increased the voltage overshoot during switching transients. In this work, the associations between CT-snubber impedance characteristics and dynamic performance (e.g. settling time and voltage overshoot) during double-pulse testing are explored using a simulation study. A fabricated CT-snubber prototype is then implemented and integrated into double-pulse testing of a silicon carbide multi-chip power module at a bus voltage of 1 kV and 400 A load, achieving damping ratios with up to 2.78x improvement over tests without the CT-snubber.