This paper discusses further modifications of the recent popular qZS-based DC/DC converter design by the introduction of the resonant LC circuit in series to the primary winding of the isolation transformer. The primary aim is to achieve the zero voltage and zero current switching of transistors. As an additional benefit of the resonant LC circuit, the converter is able to perform the voltage buck function simply by changing the switching frequency of the transistors. The control principle of the converter and its main operating modes are explained. The theoretical assumptions are experimentally verified by help of the small-scale testbench of the converter.
