A simple approach on junction temperature estimation for SiC MOSFET dynamic operation within safe operating area

A simple approach of sensorless junction temperature estimation is proposed for SiC power MOSFET devices. The junction temperature is derived in real-time by finding the instantaneous on-state resistance which is temperature sensitive and can be used as an indicator for device thermal estimation. Based on the scheme, a high-speed circuit is designed to quickly detect the on-state resistance and estimate the corresponding internal temperature. This circuit is able to provide fast thermal estimation within microseconds without using any temperature sensors. The scheme is tested on the SiC power MOSFET C2M0080120D with the laboratory hardware measurement results verified.