Combined transformer-inductor device for application to DC-to-DC converter with synchronous rectifier

A power converter, comprising:

• an input port for accepting a DC voltage;
• an output port for accepting a load to be energized;
• a combined transformer-inductor device including:
• a magnetic core including an upper member, a lower member, and a plurality of legs extending between the upper and lower member such that at least one of the plurality of legs contacts both the upper member and the lower member,
• a primary winding and a secondary winding wound around a first leg of the plurality of legs such that a high reluctance flux path is formed in the first leg, the upper member, a second leg of the plurality of legs and the lower member, and
• an auxiliary winding wound around a third leg of the plurality of legs and connected in series between the secondary winding and the output port such that a low reluctance flux path is formed in the second leg, the upper member, the third leg and the lower member, wherein said primary and said secondary windings perform a transformer function and said auxiliary winding performs an output filter function;
• a clamp switching circuit connected to said input port for periodically providing a full square waveform signal with a positive voltage to said primary winding during a first interval of a cyclic period of said power converter and said full square waveform signal with a negative voltage to reset said primary winding during a second interval other than said first interval, whereby AC flux is cancelled in said second leg to reduce a magnetic loss of said combined transformer-inductor device, wherein said clamp switching circuit further comprises a clamp device for limiting a voltage across said transformer during said second interval of said cyclic period;
• and
• a synchronous rectification circuit connected to the combined transformer-inductor device for enabling conduction from said secondary winding to said output port during said first interval and said second interval of said cyclic period, wherein said auxiliary winding is coupled between said output port and said synchronous rectification circuit for providing an inductance to filter an output signal.