Characterization of the Junction Temperature of SiC Power Devices via Quasi-Threshold Voltage as Temperature Sensitive Electrical Parameter

Conference: CIPS 2020 - 11th International Conference on Integrated Power Electronics Systems
03/24/2020 - 03/26/2020 at Berlin, Deutschland

Proceedings: ETG-Fb. 161: CIPS 2020

Pages: 6Language: englishTyp: PDF

Sharma, Kanuj; Baron, Kevin Munoz; Hueckelheim, Jan; Kocha, Dominik; Muenzenmayer, Florian; Kallfass, Ingmar (Institute of Robust Power Semiconductor Systems, University of Stuttgart, Germany)
Ruthardt, Johannes (Institute for Power Electronics and Electrical Drives, University of Stuttgart, Germany)

This paper presents a robust and easy-to-implement approach to measure the junction temperature of SiC power devices using quasi-threshold voltage as temperature sensitive electrical parameter with adjustable temperature sensitivity. The voltage drop across the parasitic inductance between Kelvin and power source is used to trigger the data acquisition circuit. The novelty of the proposed method lies in the concept of variable temperature sensitivity where the robustness decreases with the increase in the sensitivity. This concept proposes a trade-off between temperature sensitivity and robustness. A D flip-flop is used to make the acquisition circuit more robust to prevent false triggering while keeping fast switching speed and low noise susceptibility. Basic simulations, static and dynamic measurements are performed successfully on a commercially available 1.2 kV/120 A power module in a buck converter topology. The effect of DC-link voltage and load current invariance is also verified in this paper.