Gate-Source-Dependent Soft- and Hard-Switching Losses of 1200V SiC MOSFETs Utilizing Heatsinkless Calorimetric Measurements Based on Optical Sensors

Design automation is becoming increasingly prevalent in addressing the ever-increasing requirements for efficiency and power density in modern power electronics. To achieve this, accurate loss models of the used power semiconductors are essential for soft- and hard-switching applications. While the double pulse test is a well-established fast electrical characterization method for hard-switching losses, accurately determining soft-switching losses for wide bandgap semiconductors requires calorimetric measurements. Therefore an automated double pulse testbench is modularly adjusted to enable fast calorimetric measurements within the same setup. For this, a new rapid calorimetric approach is realized utilizing an external optical temperature sensor, which enables accurate measurement during operation without electromagnetic interference and improves the accuracy of loss interpolation. Furthermore, the heatsinkless approach reduces the cooldown times significantly accelerating the overall measurement speed. With the modular setup hard- and soft-switching losses in dependence of the gate-source voltage are characterized for 1200V Silicon Carbide devices.