Subcircuit Based Modelling of SiC MOSFET in MATLAB/SIMULINK

Silicon carbide (SiC) metal-oxide-semiconductor field-effect transistor (MOSFET) has been widely used in numerous industrial applications owning to their characteristics of low on-state resistance, high thermal conductivity, and high operating temperature. To fully utilize the potential of SiC MOSFET, an accurate device model is desired to evaluate the device performance before fabrication. In this article, an accurate subcircuit based model is used to describe the SiC MOSFET dynamic performance. In the model, the non-linearity of device parasitic capacitance is considered by extracting capacitance values under multiple drain-source voltage values from datasheet. All the possible circuit parasitic inductances are extracted by using ANSYS Q3D. To reduce the model complexity, the threshold voltage based model for MOSFET is adopted. Finally, the subcircuit based model is implemented in MATLAB/SIMULINK. The developed model has the advantages of high accuracy, convenient, fast execution time. The model would be a convenient tool to evaluate the device performance and help understanding the experiment phenomena. To validate the accuracy of the developed model, double pulse test (DPT) results of a 1.2 kV SiC MOSFET (ROHM) from both simulation and experiment are compared, the results shown that the developed model is an effective evaluation tool for the SiC MOSFET performance.