PURPOSE: To provide a free-running frequency in a VCO immediately after power is supplied and to normally operate an AFC immediately by providing a quick charging circuit for quickly charging an LPF corresponding to power supply and stopping quick charging corresponding to the arrival of horizontal synchronizing signals from a horizontal synchronizing separator circuit.

CONSTITUTION: A switch 15 is closed and a power supply voltage is supplied from a power supply 14 to an IC. Then, the quick charging circuit 16 immediately detects that the power supply voltage is supplied and charges the capacitor 12 and the capacitor 13 of the LPF 10. Thus, the voltage of the terminal 50 of the LPF 10 is immediately turned to a prescribed bias voltage. During the time, the oscillation frequecy of a VCO 5 is immediately turned to the free- running frequency corresponding to the voltage of the terminal 50. While the oscillation frequency of the VCO 5 is turned to the free-running frequency, the horizontal synchronizing signals are impressed from a synchronizing separator circuit 4 to the quick charging circuit 16 and the circuit 16 stops a charging operation. Thereafter, the voltage of the terminal 50 is changed corresponding to the output of a circuit 9 and the loop of the AFC circuit is closed.