Datasheet Driven Silicon Carbide Power MOSFET Model

A compact model for SiC Power MOSFETs is presented. The model features a physical description of the channel current and internal capacitances and has been validated for dc, CV, and switching characteristics with measured data from a 1200-V, 20-A SiC power MOSFET in a temperature range of 25°C to 225°C. The peculiar variation of on-state resistance with temperature for SiC power MOSFETs has also been demonstrated through measurements and accounted for in the developed model. In order to improve the user experience with the model, a new datasheet driven parameter extraction strategy has been presented which requires only data available in device datasheets, to enable quick parameter extraction for off-the-shelf devices. Excellent agreement is shown between measurement and simulation using the presented model over the entire temperature range.

I. Introduction

Unipolar devices like power MOSFETs are very attractive for switch-mode power applications due to several advantages over their bipolar counterparts such as faster switching speed, simpler drive requirements, and better current sharing due to the positive temperature coefficient of on-state resistance [1]– [3]. Despite their various advantages, silicon power MOSFETs are limited to blocking voltages of lower than 200 V due to their high on-state resistance at increased blocking voltages. At higher blocking voltages, bipolar solutions like insulated gate bipolar transistors (IGBTs) and gate turn-off thyristors (GTOs) are used which offer much lower on-state resistance, albeit at a much lower switching speed. Thus, applications requiring higher blocking voltages are limited to lower frequencies of operation which increase overall system cost due to the relatively large size of passive components like the inductors and capacitors.