MOSFET 양단 전압 감지 기반 선택적 동작이 가능한 고효율 RM 스너버

Abstract

With the rapid adoption of electric vehicles, there are increasing demands for the miniaturization and weight reduction of power‐conversion systems. Although raising the switching frequency enables dowonsizing passive ‐components, the high-frequency resonance between MOSFET’s output capacitance and parasitic inductance induces severe voltage ringing. Conventional RC, LC, and active snubbers can mitigate those side effects but suffer from excessive loss, increased volume, and control complexity. This paper proposes a snubber topology that replaces snubber’s capacitor with a MOSFET, thereby reducing equivalent capacitance and power losses in the snubber. An integrated overvoltage detection circuit at the MOSFET’s gate driver actively damps ringing and secures precise voltage regulation. Experimental validation on a 60 W flyback converter demonstrates power loss reduction of 0.3–0.6 W in the snubber circuit compared with a conventional RC snubber, alongside enhanced voltage‐control performance. The proposed snubber circuit thus offers a compact and high‐efficiency solution for high frequency power converters.