Automated Calorimetric Measurement with a Peltier Element for Switching Loss Characterization

In this work a novel approach for an automated calorimetric measurement of soft-switching losses of wide-bandgap semiconductors with the aid of a Peltier element is shown. The Peltier element is used to either cool down or heat up the heat-sink and the device under test in a thermally isolating chamber. The derivation of the losses in dependence of the individual thermal properties as well as a simplified solution is given. Finally, measurements are shown which prove the functional principle for soft-switching losses of SiC and GaN transistors and confirm excellent match between the modeled and calorimetrically determined and electrically measured losses.