Patent ID: 8213193
Filing Date: 2012-07-03
Classification: H02M

Abstract:
1. A flyback DC-DC converter for converting a DC input voltage to a DC output voltage, comprising: a transformer for receiving the DC input voltage, converting the DC input voltage to the DC output voltage, and generating a feedback voltage, wherein the transformer comprises: an output transistor, wherein the first secondary winding is coupled between a source terminal of the output transistor and ground and wherein the third secondary winding is coupled between the source terminal and a gate terminal of the output transistor; an input switching circuit coupled to the transformer; an analog controller coupled to the input switching circuit and operable for triggering a skip operation if the feedback voltage is higher than a preset reference voltage at the end of a turn-off period of the input switching circuit and also for regulating the DC output voltage according to the DC input voltage and the feedback voltage; and a first switch coupled to the second secondary winding, and controlled by the analog controller, wherein the first switch is switched on during the skip operation, and switched off during the turn-off period.