Challenges in switching waveforms measurement for a high-speed switching module

As SiC MOSFET is moving towards high current rating through parallel devices in a module, the ability to switch it fast with minimum switching loss becomes a new challenge. Amid this new challenge, power converter designers need to deal with more demanding measurement method to obtain correct switching waveforms. Switching waveforms are an important asset for converter designers because they can reveal vital parasitic information, indicate any potential overshoot or undershoot and estimate the switching loss. This paper shares the experimental work results, its measurement techniques (current and voltage) and test setup use to obtain minimum voltage overshoot of a 5 parallel SiC devices module. The cable length (of voltage probe) is shown to directly affect the switching loss estimation especially when a fast 5Ω gate driver resistance is used.