Is an antiparallel SiC-Schottky diode necessary? Calorimetric analysis of SiC-MOSFETS switching behavior

Within this paper the switching losses of a Wolfspeed 25mOhm bare die SiC-MOSFET are measured in a hard switching 800 V DCDC-converter with five different commutation partners. A small and a large SiC Schottky diode, an SiC-MOSFET body diode and a combination of body and Schottky diode are compared at different switching speeds and switching currents. The results show quite well the reverse recovery charge dependence of SiC-MOSFET's body diode on switching speed. In contrast to common electric measurements where losses are calculated, the calorimetric measurements reveal exactly what shall be quantified: The temperature rise of the switching MOSFET.