| 摘要 |
PROBLEM TO BE SOLVED: To obtain the PLL circuit with low power consumption that realizes a high-speed lockup. SOLUTION: This phase-locked lop circuit has a phase difference conversion circuit consisting of a voltage controlled oscillator 108, a frequency divider 102 that frequency-divides an output of the voltage controlled oscillator 108, a reference frequency generator 101, a phase comparator 103 that compares a phase of an output of the reference frequency generator 101 with the phase of an output of the frequency divider 102, a charge pump 104 that converts a phase difference signal outputted from the phase comparator 103 into a control voltage of the voltage-controlled oscillator 108, and a low-pass filter 107. Furthermore, the phase-locked loop circuit also has a means that compares a phase difference obtained from an output of the phase comparator 103 with a reference value, to decide the quantity of the phase difference and a means that changes a power supply voltage applied to the phase comparator 103 and the charge pump 104, based on the decision result. |
