Self-Oscillating DC-DC Resonant Converter

Analysis and design of a self-oscillating DC-DC resonant converter are presented. This converter is capable to operate with high switching frequency without driver integrated circuits. The driver function is implemented with a small self-oscillating low-power resonant tank independent of the resonant power tank for the DC load. With this scheme, the advantages of the self-oscillating resonant converters like high power density, reliability and low cost are obtained, as well as independence between load and switching frequency are reached. The self-oscillating tank is analyzed with descriptive function method. Finally, analysis and proposed scheme is validated with the implementation of a 500 kHz, 24 to 130V step-up converter. Error in switching frequency prediction is -1.3 %, power consumption of the driver is around 2.1W.