Modeling of SiC MOSFET with temperature dependent parameters and its applications

A model of Silicon carbide (SiC) MOSFET based on PSpice is proposed in this paper, which is suitable for a wide temperature range especially at low temperature. The static characteristics of SiC MOSFET are described by introducing temperature dependent voltage source and current source. The effect of negative turn-off gate drive voltage is also taken into account in the modeling. In order to reflect the low temperature characteristics of SiC MOSFET accurately, low temperature (-25°C) measurements are carried out, which provide the modeling basis. The determinations of key parameters in the model are analyzed in detail, including on-state resistor, internal gate resistor, temperature dependent sources, and some capacitors. The proposed model is verified by the experimental tests on a Buck converter prototype at different input voltages, input currents and temperatures. Simulation results on the proposed model coincide well with the experimental results, in terms of switching waveforms and power losses even at low temperature. The comparison between SiC MOSFET and Si MOSFET on switching characteristics and the efficiency comparison of Buck converter using SiC devices and Si devices are presented, which demonstrate the attractive advantage of SiC devices in power loss reduction.