Abstract: For use with a power converter having a rectifier that receives current from a secondary side of transformer and delivers the current to an output thereof via an output inductor, a low loss clamp for, and method of, attenuating ringing energy in the secondary side. In one embodiment, the clamp includes: (1) an auxiliary transformer coupled across a component in the secondary side and (2) an auxiliary switch, interposed between the auxiliary transformer and the output, that operates as a function of a voltage of the output to cause the auxiliary transformer to receive at least a portion of the ringing energy and deliver the portion to the output.

Abstract: For use in a power converter having a controlled full bridge coupled to a transformer, the bridge delivering power received from an input of the power converter to a primary winding of the transformer, a circuit for, and method of decreasing conducted and radiated electromagnetic interference of the power converter. In one embodiment, the circuit includes a switching circuit, coupled across at least a portion of the primary winding, that closes to short the portion as a function of a state of the full bridge to stabilize a voltage level of the primary winding and reduce ringing caused by the intrinsic capacitance, thereby decreasing the conducted and radiated electromagnetic interference.