Phase shift circuit and power factor correction circuit including the same

A power factor correction circuit, comprising:

• a detection circuit unit detecting current flowing in inductors included in a main circuit and a sub circuit, respectively, to generate a voltage pulse signal;
• a control unit operating a switch device during every period of the voltage pulse signal to charge and discharge a capacitor and generate a control signal;
• and
• a driving circuit unit determining operations of switches included in the main circuit and the sub circuit, respectively, based on the control signal and the voltage pulse signal,
• wherein the control unit charges and discharges the capacitor to generate a ramp signal and compares a reference signal determined from the ramp signal with the ramp signal to generate a clock signal, and
• a negative or positive value of offset components included in the reference signal or the ramp signal is changed during every operating period of the switch device.