A New Soft-switching Synchronous Buck Converter without Auxiliary Switch

Soft-switching operation of a synchronous buck converter without auxiliary switch is researched in this paper. The synchronous buck converter uses the auxiliary inductor L-r and the auxiliary capacitor C-r to realize the zero-voltage switching (ZVS) of the main switching device. It can reduce turn-on losses of the buck converter. In this paper, the operating principle of synchronous buck converter is introduced. The main waveforms in each mode are analyzed. Finally, the simulation of proposed synchronous buck converter is carried out and experimental platform is built. Both simulation and experimental results are provided to show that the synchronous buck converter proposed in this paper realizes ZVS operation of the switch and then the efficiency can be improved.