Several topologies of active-clamped DC-DC converters have been proposed before. This paper compares the common-mode noise properties of the conventional type using a pulse transormer for a gate driver and the common-source type proposed recently. Using a noise measuring system composed of LISN (Line Impedance Stabilization Network) and EMSCAN (Electromagnetic Scanning System), it was clarified that the common-source type has the superiority on noise reduction to the conventional one.
