Junction temperature is a key parameter to monitor the reliability of power devices in converters. Currently, the temperature sensitive electrical parameters (TSEPs) are preferable to measure the junction temperature in real-time operation, but there are only a few practical implementations methods. This paper proposed a novel real-time junction temperature monitoring circuit for SiC MOSFET based on its quasi-threshold voltage (quasi-Vth) without complex circuits and current sensors. First, the temperature dependence of its quasi-Vth is analyzed. Then, the principle of the measurement circuit is introduced. Finally, a double pulse test setup is built to validate the measurement circuit. The experimental result shows that the quasi-Vth of SiC MOSFET extracted by the proposed measurement circuit has a sensitivity of -4.37mV/℃ and is independent of load current.
