Power supply device having improved power conversion efficiency in light load conditions

Abstract

There is provided a phase shift full bridge (PSFB) type power supply device controlling a switching on time of lagging leg switches according to a load state. The power supply device includes a power supply unit supplying preset DC power by switching input power using a full bridge by a phase shift method; and a control unit controlling a switching time of a switch of the full bridge according to a load state in which the DC power is received from the power supply unit.