A novel LLC multi-resonant DC-DC converter with an anti-resonant circuit

A novel LLC multi-resonant DC-DC converter with an anti-resonant circuit is presented in this paper. The LLC DC-DC converter proposed herein can improve the sensitivity of voltage conversion ratio in the step-down area, and then achieve the excellent performance on the output voltage and power regulations by pulse frequency modulation (PFM) under soft switching conditions. The theoretical analysis and the experiment results on the essential switching and steady-state performances of the proposed DC-DC converter are described, and the practical effectiveness is verified. In addition, the performance comparison between the voltage doubler (VD) and full bridge (FB) diode rectifier applied for the proposed LLC DC-DC converter is discussed in terms of a conversion efficiency and soft switching performances.