A passive clamp circuit for BIFRED converter

BIFRED is a well-known single-stage AC/DC converter. The converter integrates a power factor corrector stage and a DC-DC stage to a single switch converter. Due to this integration the leakage inductance of the transformer has a pronounced effect on the voltage stress of the switch. In this paper we propose a passive clamp circuit that clamps the voltage over the switch to a relatively low and predictable value. This allows for the use of a switching device of a lower voltage rating and, therefore, a device with a lower on-resistance and conduction losses.