公开(公告)号：US20140321174A1

公开(公告)日：2014-10-30

申请号：US14330667

申请日：2014-07-14

Applicant: RENESAS ELECTRONICS CORPORATION

Inventor： Kazuhito AYUKAWA ,  Nobutoshi KASAI ,  Daisuke IIJIMA

IPC: H02M7/217

CPC classification number: H02M7/2176 ,  H02M1/4225 ,  H02M2001/0032 ,  Y02B70/126 ,  Y02B70/16

Abstract: Switching loss is reduced by decreasing the switching frequency of a PFC power supply in light load condition, whereas the switching frequency is maintained high in heavy load operation. Efficiency in light load operation is thus improved without enlarging a boosting inductor and an output smoothing capacitor. A capacitor is provided in a triangular wave generating circuit and the triangular wave generating circuit outputs a triangular wave by charging and discharging this capacitor. Charging and discharging of the capacitor are controlled by an oscillation frequency control circuit output current which is input to a comparator.

Abstract translation: 通过在轻负载条件下降低PFC电源的开关频率来减少开关损耗，而在重负载操作中开关频率保持较高。 因此，在不增大升压电感器和输出平滑电容器的情况下，轻载操作的效率得到改善。 在三角波产生电路中提供电容器，并且三角波产生电路通过对该电容器进行充电和放电来输出三角波。 电容器的充电和放电由输入到比较器的振荡频率控制电路输出电流来控制。