An analytical switching model of SiC MOSFET considering the junction temperature characteristics

Abstract

In order to provide convenience in the design work as the manufacturer-supplied models of silicon carbide (SiC) metal oxide semiconductor field effect transistor (MOSFET) are generally only applicable to specific software, an analytical switching model of SiC MOSFET considering the junction temperature characteristics based on MATLAB is proposed in this article. The junction temperature characteristics of the parameters required for the switching process, including threshold voltage, on-resistance and transfer characteristics of SiC MOSFET, threshold voltage and output characteristics of body diode, which are extracted from the datasheet of the SiC MOSFET provided by the manufacturer. Then a model for the transient process of the test circuit, including the non-linear capacitance, the parasitic resistance and parasitic inductance from package and the printed circuit board is created. After that, each sub-stage of the switching process is analyzed in detail, then the analytical model is solved numerically using MATLAB. Finally, the SiC MOSFET C3M0075120K manufactured by Wolfspeed is selected as the case study to verify the built model, and the accuracy is validated by comparing with the LTspice simulation and experiment results. As a result, the proposed model can be applied, especially in designs involving junction temperatures.