Voltage overshoot and ring will occur during metal-oxide semiconductor field-effect transistor (MOSFET) turn-off, when it is embedded in circuits with inductive load and operates in pulse width modulation mode. The voltage overshoot and ring not only increase the system voltage stress, but also produce radiated and conducted electromagnetic interference. Based on the analysis of the influence of the gate voltage on the MOSFET turn-off behaviour, this study presents an active closedloop gate voltage control method to mitigate the voltage overshoot and ring. The proposed method senses the instant when the MOSFET drain current starts to fall by comparing the drain voltage with the bus voltage. Once the instant has been detected, a turn-off assistance voltage with proper amplitude and adjustable duration is generated and applied to the gate to mitigate the overshoot and ring. The delay of the gate control loop, including the delay of the comparator, can be compensated by proper choice of the components. Both simulations and experiments results indicate that the MOSFET turnoff voltage overshoot is largely reduced and the ring is almost completely eliminated. At the same time, the turn-off loss and EMI are also minimised.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.