A Criterion for an Optimal Switching of Power Transistors

Power converters, especially those exploiting fast-switching devices, suffer from ringing, which worsens efficiency, EMI performance and increases the stress of components. Traditional approaches, such as RC snubber and series gate resistance, only partially mitigate the problem, whereas, active gate driver implies sub-optimal switching waveforms. This paper presents a new criterion for controlling the turn-on and the turn-off of a power transistor using a three-levels current driver, which results in optimal switching waveforms. The method shows better performance in terms of efficiency and transient slopes compared to traditional approaches.