For dynamic measurements, the increase in switching speed offered by GaN transistors requires good measurement technology, as well as good techniques to capture important details of high-speed waveforms. AN023 Accurately Measuring High-Speed GaN Transistors application note focuses on how to leverage the measurement equipment for the user’s requirement and measurement techniques to accurately evaluate high-performance GaN transistors. In particular, differential probes specifically intended for this type of measurement are recommended like Tektronix IsoVu, LeCroy DL-ISO, and PMK Firefly probes.
Switching loss measurement is common. However, GaN devices are small and fast, so adding probes significantly impacts the measurement. To capture a reliable and high-fidelity waveform, it is important to use a proper probing technique together with a probe having low input capacitance and a short ground loop connection feature.
Effect of measurement techniques and choice of measurement point
For additional information on repeatable, reliable dynamic characterization of low-voltage GaN FETs, see the article Accurate Characterization of Low-Voltage, Small-Form–Factor GaN FETs.