Temperature Sensitive Electrical Parameters for Condition Monitoring in SiC Power MOSFETs

This paper presents an analysis of the turn ON transient for SiC power MOSFETs and defines a Temperature Sensitive Electrical Parameter (TSEP) which is suitable for condition monitoring.The drain current switching rate dIDS/dt and its temperature dependency have been measured and analysed for commercially available 1.2 kV/10 A, 1.2 kV/24 A and 1.2 kV/42 A SiC MOSFETs from Wolfspeed showing that at lower switching speeds, i.e. using high gate resistances, it can be a suitable TSEP for condition monitoring.The impact of temperature on the switching speed indicates that the current switching rate is a more effective TSEP for higher current rated devices and the evaluation of the switching losses suggests that the sacrifice in switching speed for enabling the ability of estimating the junction temperature is not a major trade-off.