| 摘要 |
PROBLEM TO BE SOLVED: To provide a PLL circuit whose operation is stabilized. SOLUTION: The PLL circuit is provided with a control means 14 that controls a charge pump current depending on a frequency of an input signal and with a switch circuit that controls an output current of a voltage current converter synchronously with the operation of a charge pump 15 to provide a prescribed frequency deviation to an output signal from a current controlled oscillator 18 and controlling the charge pump current in response to the frequency of the input signal can stabilize the operation of the PLL circuit independently of the frequency of the input signal. Since the output current of the voltage current converter is controlled synchronously with the operation of the charge pump, a prescribed frequency deviation is provided to the output signal of the current controlled oscillator and omitting a loop filter resistor can avoid a band widthωn from being fixed.
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