Beyond RDS(on): Rethinking MOSFET Selection in Isolated DC-DC Converters

In high-density isolated DC-DC converters, performance depends on more than RDS(on). Switching charge, output capacitance, commutation behavior, and temperature also affect efficiency, thermals, and power density.

This presentation examines a 200W active-clamp forward converter in which two parallel 120V primary MOSFETs were replaced by one 150V SuperQ® MOSFET without changing the topology or gate drive. The change improved efficiency, reduced system loss by approximately 2W, and lowered MOSFET temperature by 31°C.

Attendees will learn how advanced silicon can improve performance and voltage margin while reducing component count and simplifying the power stage.