Online Junction Temperature and Current Simultaneous Extraction for SiC MOSFETs With Electroluminescence Effect

In this letter, a junction-temperature and current extraction method is presented based on the electroluminescence mechanism of the SiC mosfet body diode. Starting from the observation of two characteristic peaks in the emitted light spectrum, we proved that the junction temperature and the drain current can be simultaneously measured. This novel method consists of decoupling the relationship between the intensity of the electroluminescence peaks, the current, and the temperature. Through this optical method with inherent electrical isolation, the junction temperature and current in the SiC chip can be simultaneously measured with high precision. The total error of the junction temperature estimation is within ±3 °C, and the error of the current estimation is about ±0.2 A.