Patent ID: 9225235
Filing Date: 2015-12-29
Classification: H02M,Y02B

Abstract:
1. A power factor correction circuit comprising: a power conversion circuit unit controlling an inductor current according to a switching signal applied to a main switch to convert an external input voltage into an output voltage having a predetermined range; an imbalance detection circuit outputting an imbalance state signal when the external input voltage is in an unbalanced state by using the inductor current, wherein when a level of the inductor current is equal to or lower than a pre-set level and an ON time of the switching signal is equal to or longer than a pre-set duration, the imbalance detection circuit unit determines that the external input voltage is in the unbalanced state; and a soft start circuit unit performing soft starting by adjusting the switching signal when the imbalance state signal is output by the imbalance detection circuit unit.