A New Soft-Switching Forward DC-DC Converter Operating in Discontinuous Conduction Mode

The paper presents a simple soft-switching forward DC-DC converter suitable for low power applications. A lossless passive turn-off snubber is employed to provide zero voltage turn off of the switch as well as transformer reset. Moreover, the choice to operate the converter in discontinuous conduction mode (DCM), while providing zero current turn on of the switch, also allows to simplify the topology by eliminating the inductive output filter. A detailed converter analysis, aimed to highlight advantages and drawbacks of the presented topology, is reported, together with a suitable design procedure. Experimental results are also included to verify the theoretical expectations.