A soft-switching synchronous buck converter for Zero Voltage Switching (ZVS) in light and full load conditions

This paper proposes a new soft switching synchronous Buck converter to provide complete ZVS conditions for both high and low side MOSFETs under the light- or no-load, as well as full load conditions. In the continuous conduction mode (CCM) with a heavy load current condition, the high side MOSFET is generally turned ON while the body diode of low side MOSFET is in the conducting condition in a dead-time region, which causes switching loss in the high side MOSFET. A proposed soft-switching Buck converter consists of the conventional synchronous Buck converter with additional L and C. By using a resonance with the additional L and C, the inductor current in CCM can be effectively commutated from the low side body diode to the high side body diode of the two MOSFETs during the dead time region. The detailed modes of operation with experimental results are provided to verify performance.