Estimating Junction Temperature of SiC MOSFET Using Its Drain Current During Turn-On Transient

Silicon carbide metal-oxide-semiconductor field-effect transistor (SiC MOSFET) has become a promising device due to its excellent material properties. Junction temperature is an important parameter and a significant health index. In this article, drain current during turn-on transient is taken as the thermo-sensitive electrical parameter (TSEP) to monitor the junction temperature of SiC MOSFET. Based on the physical properties of wide bandgap semiconductor materials, the switching behaviors of SiC MOSFET and the variation of drain current with temperature were studied. The influence of temperature dependence of threshold voltage and carrier mobility on drain current is analyzed. It is proven that the drain current has a positive temperature coefficient during turn-on transient. Finally, the validity of the proposed method is verified by the theoretical analysis and experiments.