Wide Bandwidth Current Sensors and the Influence on the Switching Loss Characterization

Due to their outstanding properties, wide bandgap semiconductor devices enable better performance and efficiency in power electronic circuits compared to silicon devices. However, characterizing the switching loss of such devices is even more challenging. The limits of measurement equipment, especially for the current measurement, are reached due to the fast rise and fall times. Ideal characterization requires a non-invasive, infinite bandwidth current sensor. This paper presents a galvanically isolated current sensor that combines magnetic field sensors and a printed circuit board integrated Rogowski coil. The insertion inductance of the hybrid current sensor is compared to a commercial coaxial shunt and a low inductance SMD shunt approach. The influence of the different current measurement devices on the switching loss characterization is investigated.