Using surface mounted resistor for power module switching current measurement

This paper introduces a novel approach of using surface mount resistor (SMR) for measuring switching current in power module applications. To overcome the challenge of the SMR parasitic inductance on measurement results, the SMR impedance is characterised first and used to compensate the switching current measurement results. To validate the approach, a SiC-MOSFET half-bridge circuit is built and both Rogowski coil and SMR are used to measure the switching current. The switching current measured by SMR using our proposed approach shows agreement with the results obtained by Rogowski coil. The measurement error without using our proposed approach is quantified, and illustrates that our proposed approach helps to reduce the measurement error. Thus, it provides a compact switching current measurement solution by comparing with state-of-the-art current measurement approaches, which shows that it is promising for future highly integrated wide bandgap power module application.