A Unified Physical PSPICE Model of SiC MOSFET With Automatic Parameter Extraction

Abstract

The terminal capacitances of SiC power devices can significantly influence their switching characteristics. Consequently, it is crucial to accurately characterize the nonlinear characteristics of terminal capacitances. This article provides a unified PSPICE modeling approach for SiC MOSFET that is based on the physical characteristics of nonlinear terminal capacitance. The model takes into account the depletion region variation and structure of terminal capacitance during the operation of planar gate SiC MOSFET. The terminal capacitances are calculated by analyzing their dual dependence on the gate-to-source voltage $V_{\text {gs}}$ and drain-to-source voltage $V_{\text {ds}}$ . More importantly, an automatic parameter extraction method is proposed for the model to extract the unknown parameters that are in accordance with the experimental characteristics. The proposed modeling method precisely depicts the relationship between the three terminal capacitances and the two independent variables, i.e., $V_{\text {gs}}$ and $V_{\text {ds}}$ , thereby circumventing the challenge of acquiring $CV(C$ – $V_{\text {gs}}$ and C– $V_{\text {ds}}$ ) characteristics curves. To confirm the proposed model’s accuracy and generalizability for planar-gate SiC MOSFET, investigations are conducted using two distinct planar-gate SiC MOSFET devices: the SiC MOSFET C2M0080120D (1200 V/36 A) and the SCT30N120 (1200 V/45 A). The measurements from the double-pulse experiments are in good accordance with the results by our model. In addition, the convergence capability of our proposed model is confirmed through PSPICE simulation of a BUCK converter.