Abstract: A new ZVCS CLL resonant push-pull DC-DC converter is presented in which the resonant circuit is located at the secondary side of the transformer. The proposed converter topology is suitable for unregulated low voltage to high voltage power conversion, as in battery- powered system. The MOSFET primary switches and output rectifier turn-on and turn-off operate under zero-voltage and zero-current switching conditions. Circuit simulations and experimental results are presented and are shown to have excellent agreement with fundamental mode analysis.