Stability Modeling for Multichip SiC MOSFET Power Modules

Abstract:
Compared with silicon counterparts, SiC MOSFETs feature more sensitive gate oxide and have more susceptibility to gate failure. To predict and suppress gate voltage oscillations, this paper proposes an accurate stability model for the differential-mode (DM) inter-chip oscillation occurring inside multichip SiC MOSFET power modules. The electrical parameters of SiC MOSFET chips and packages depend on the bias condition which varies significantly during large signal transients. Taking into account all determining factors, e.g., voltage, current, frequency and temperature, the proposed stability model enables to accurately predict the DM inter-chip oscillations for different module layouts and switching conditions. Simulation and experimental results agree well with the theoretical analysis, verifying the accuracy of the proposed stability model.