New Resonant Step-Down/Up Converters

This paper presents two new resonant step-down/up converters, where all active elements operate under soft-switching condition independent of load and operating voltages. One of the proposed converters has positive voltage gain and the other has negative voltage gain. Although, the proposed topologies are similar to that of the single ended primary inductor converter, operations of the proposed converters are completely different. In fact, the inductors and coupling capacitor create resonant networks. Thereby, not only soft-switching condition is achieved, but also the passive components size is reduced considerably. Experimental results from a 250 W laboratory prototype verify the presented operation and theoretical analysis of the proposed converters.