Accurate Calorimetric Switching Loss Measurement for 900 V 10 mΩ SiC MOSFETS

This letter presents and evaluates three accurate (+/- 20 %) calorimetric switching loss measurement methods, which are capable of measuring hard- and soft-switching losses at high speed (20-25 min/point) compared to other calorimetric methods. A comprehensive switching loss measurement data accuracy analysis is done, setting the benchmark for the accuracy analysis of switching loss data. The high accuracy in the switching loss data is obtained by a high ratio of switching losses to total measured losses in the Device Under Test. This is achieved by using a full-bridge configuration, where the conduction losses are reduced up to 80% in the Device Under Test by utilizing the duty cycle as an additional degree of freedom compared to a half-bridge configuration. Furthermore, the proposed calorimetric methods yield more reliable switching loss data than electrical methods, particularly than the double pulse test. Switching loss data are presented for the 900 V, 75 A, 10 m Omega SiC MOSFETS from CREE, that are one of the first discrete SiC MOSFETS to come with a TO-247-4 package.