New digital control circuit of the series resonant DC-DC converter with auxiliary switches

The series resonant DC-DC converter with auxiliary switches has advantages to keep the power efficiency high for the relatively wide range of the load and to prevent the switching frequency from extreme lowering under the light load condition. This paper presents a new digital control circuit of the series resonant DC-DC converter with auxiliary switches and the analysis of the circuit operation and output characteristics of this digitally controlled DC-DC converter. As a result, it is clarified that using the proposed digital control circuit, the power efficiency is improved in the relatively light load region.