Comparison and analysis of short circuit capability of 1200V single-chip SiC MOSFET and Si IGBT

Abstract

Short circuit capability of commercial SiC MOSFETs is analyzed, which is compared with that of commercial Si IGBTs. Junction temperatures during short circuit tests are analyzed in this work. A test bench is designed for short circuit tests of discrete MOSFETs and IGBTs. Commercially available 1200V SiC MOSFETs from Wolfspeed (C2M0080120D) and 1200V Si IGBTs from Infineon (IKW25N120H3) with similar current rating are tested. The short circuit withstand time (tcr) of the 1200V SiC MOSFET is much shorter than that of the 1200V Si IGBT. A 1-D transient finite element thermal model based on structure parameters is constructed to investigate the junction temperature curves during short circuit. According to the analysis of heat generation, short circuit capability of the SiC MOSFET is mainly restricted by high electric field at the P-N junction and high short circuit current density.