Real-Time Measurement of Temperature Sensitive Electrical Parameters in SiC Power MOSFETs

This paper examines a number of techniques for junction temperature estimation of silicon carbide (SiC) MOSFETs devices based on the measurement of temperature sensitive electrical parameters for use in online condition monitoring. Linearity, sensitivity to temperature, and circuit design for practical implementation are discussed in detail. A demonstrator based on the measurement of the quasi-threshold voltage, the turn-on transient characteristic (di/dt), the on-state voltage, and the gate current peak is designed and validated. It is shown that the threshold voltage, the estimation of the gate current peak, and the on-state voltage have potentially good sensitivity to temperature variation and linearity over a wide operating range. Very low sensitivity to temperature is shown for di/dt. The proposed method can provide a valuable tool for continuous health monitoring in emerging applications of SiC devices to high-reliability applications.