A self-bias supply scheme for the control circuit in power converter

This paper proposes a novel self-bias supply scheme for the control circuit in dc-dc converters to improve the efficiency. Compared with existing methods such as auxiliary winding, linear voltage regulator, the proposed method can achieve better efficiency and more stable voltage for the control circuit. An auxiliary switch paralleled with the main switch is used to get the bias voltage for control circuit. This auxiliary switch works in an intermittent mode which can reduce the switching losses. The proposed method is validated on a 64-W flyback converter prototype.