Fast Power Semiconductors Switching Current Measurement by Current Surface Probe^*

With the advantage of high bandwidth and small insertion impedance, a current surface probe (CSP) used to measure switching current waveforms is presented in this paper. Its transfer impedance is characterized and validated by measuring an IGBT switching current that is compared with those obtained with a current probe (CP), a current shunt (CS) and a Hall effect current probe (HECP). Furthermore, by comparing with a CS to measure a GaN-HEMT switching current, it is shown that CSP is able to measure a switching current of a few nanoseconds, while it brings no influence on transistor voltage waveform measurement. The obtained results show that, the use of CSP brings little parasitic inductances in the measurement circuit and it does not bring the connection of the ground to the power converter, which is the case for the CS.