| 摘要 |
A PLL circuit includes first and second charge pump circuits controlling an output voltage according to an output signal of a phase comparator, a first filter filtering out predetermined frequency component included in a signal generated according to current output from the first charge pump circuit, and outputting the signal as a first voltage signal, a second filter inputting a current output from the second charge pump circuit and outputting a predetermined constant voltage as a second voltage signal, a voltage control unit outputting a third voltage signal according to a comparison result between the first voltage signal output from the first filter and a reference voltage signal, and a voltage controlled oscillator that has a first low gain property, a second low gain property, and a high gain property, and is controlled by the first to third voltage signals to generate an oscillating frequency.
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