Push-pull current-fed multiple-output regulated wide-input-range DC/DC power converter with only one inductor and with 0 to 100% switch duty ratio: operation at duty ratio below 50%

Abstract

The circuit has only one inductor for any number of outputs, one transformer and low sensitivity to transformer volt-second unbalance, only two power switches, and no need for two power switches in cascade. It is suitable for operation from 0 to <100% switch duty ratio (buck-like or boost-like action), accomodating a very wide range of input voltage. A previous paper [2] gave design equations for operation at duty ratios of 50% or more (boost-like operation). That analysis is extended here to include duty ratios below 50% (buck-like operation). Unusual features of the circuit are described and the most-important design equations are presented.