Abstract: There are provided a phase shift circuit and a power factor correction circuit including the same. The phase shift circuit includes a switching circuit unit charging power in or discharging power from a capacitor through a plurality of switching devices and comparing a voltage of the capacitor with a predetermined reference voltage, and a clock generating unit generating a reference clock signal based on an output of the switching circuit unit, wherein the switching circuit unit turns the plurality of switching devices on or off, based on currents from inductors respectively included in a main circuit and a sub-circuit of a power factor correction circuit to determine a polarity of the voltage of the capacitor.

Abstract: A phase shift circuit may include a ramp generation unit charging or discharging a capacitor connected to a switch device to generate a ramp signal, a reference signal generation unit generating a predetermined reference signal from the ramp signal, and a comparison unit comparing the ramp signal with the reference signal to generate a clock signal, wherein at least one of the reference signal generation unit and the comparison unit changes a negative or positive value of offset components included in the reference signal or the ramp signal within every operating period of the switch device.

Abstract: There is provided a power factor correction circuit including: 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; 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.

Abstract: The present invention relates to a PFC control circuit, an active PFC circuit, and a PFC control method. According to an embodiment of the present invention, a PFC control circuit including: an inductor current sensing unit for sensing an inductor current of a PFC circuit; an output voltage feedback unit for outputting a feedback output signal; a sensing and feedback signal application unit for outputting a sensing voltage signal during switching duty on of the PFC circuit and adding the feedback output signal to the sensing voltage signal to output the added signal during switching duty off of the PFC circuit; and a PFC control unit for generating a comparison signal and generating a duty control signal from the comparison signal and a first reference signal to make variations due to an internal offset be removed or reduced is provided.

Abstract: There is provided a power factor correction circuit including: 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; 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.

Abstract: There are provided a phase shift circuit and a power factor correction circuit including the same. The phase shift circuit includes a switching circuit unit charging power in or discharging power from a capacitor through a plurality of switching devices and comparing a voltage of the capacitor with a predetermined reference voltage, and a clock generating unit generating a reference clock signal based on an output of the switching circuit unit, wherein the switching circuit unit turns the plurality of switching devices on or off, based on currents from inductors respectively included in a main circuit and a sub-circuit of a power factor correction circuit to determine a polarity of the voltage of the capacitor.