| 摘要 |
PURPOSE:To improve the rise of PLL at the starting of a horizontal period by supplying a signal phase-modulated by the remaining jitter of a color video signal to a phase comparator and reducing the remaining jitter with an output oscillated from a VCO. CONSTITUTION:A PLL30 consists of a phase comparator 31, a low-pass filter 34, a VCO32, and a divider circuit 33. When a phase modulating signal Sm is supplied to the PLL30, a signal Sh is supplied to a VCO32 as a start/stop controlling signal for the oscillation of the VCO and the signal Sh=''1'', the VCO32 oscillates. The signal Sh is supplied to the circuit 33 as a clear signal and the circuit 33 is cleared at the signal Sh=''0''. When the signal Sh is supplied to an error reset circuit 42, an error control signal Se is formed and supplied to the circuit 31. When the signal Sh is changed from ''0'' to ''1'', the circuit 42 outputs error voltage of prescribed level to the circuit 31. |
