A Novel Control Scheme of Synchronous Buck Converter for ZVS in Light-Load Condition

This paper proposes a new control technology that enables a synchronous rectifier (SR) buck converter to realize zero voltage switching (ZVS) in light load condition. The SR control technique is applicable to dc low voltage output because the replacement of output rectifier diode by MOSFET can minimize conduction losses and increase the efficiency of the whole circuit. However, the technique cannot achieve good efficiency in light load condition. The control technique introduced in this paper enables an SR buck converter to carry out ZVS in light load condition to increase efficiency. No extra auxiliary switches or RLC passive components are required; thus, it is low cost and easy to control. The output of buck converter with 5 V/25 W featured by SR is developed in this paper; the availability of the technique introduced, herein, is also proven. The experimental results are satisfactory.