SOFT-SWITCHED SQUARE-WAVE HALF-BRIDGE DC-DC CONVERTER

A constant-frequency zero-voltage-switched square-wave dc-dc converter is introduced, and results from experimental half-bridge implementati ons are presented, A nonlinear magnetic element produces the advantage ous square waveforms, and provides isolated terminals from which the o utput voltage may be controlled. Semiconductor stresses and losses are minimized both by the square waveforms and by low switching losses. T he active switches and the output rectifiers both exhibit zero-voltage switching. The active switches (metal-oxide-semiconductor field-effec t transistors (MOSFETs)) are operated at a fixed frequency with 50% du ty cycle, which allows the use of a simple open-loop gate drive. Exper imental implementations verify predicted operation.