| 摘要 |
PURPOSE:To keep constant the delay ratio of a signal, which is supplied to a delay circuit, to the transmission signal of an oscillator by changing a voltage to control the operation of the delay circuit corresponding to the change of the signal to be sent out by the oscillator. CONSTITUTION:Since the signal of a suitable frequency is sent out from a VCO 4, frequency division is executed by a 1/n frequency divider 5 to the period of a reference clock signal, which is supplied to a phase comparator 1, and the period of the signal sent out by the VCO 4 and phase difference to the period of a signal to be sent out by the said frequency divider 5 is detected by the phase comparator 1. Then, the phase comparator 1 sends out the signal of the period corresponding to the phase difference through an LPF 2 to a control voltage supply part 3. Since a normal state is disturbed by changing the period of the reference clock signal to be supplied to the phase comparator 1, a new normal state is generated in a PLL loop and the voltage to be supplied from the control voltage supply part 3 to a variable delay part 6 is changed as well. |
