| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a phase locked loop device with a load capacitor varied by a frequency. <P>SOLUTION: The present invention comprises a phase detector, a charge pump and a voltage controlled oscillator (VCO). The VCO comprises a control signal generator and an internal signal generator. The control signal generator inputs a pumping signal outputted from the charge pump, generates an inactive variable control signal if a frequency of an external clock signal is higher than that of an internal clock signal, and generates an active variable control signal if the frequency of the external clock signal is lower than that of the internal clock signal. The internal signal generator comprises an inverter for feeding back the internal clock signal for inputting, and inverting this input to generate the internal clock signal, a load capacitor connected in parallel to an output terminal of the inverter, and an MOS transistor, connected in series to the load capacitor, to be active when the variable control signal is active, or to be inactive when the variable control signal is inactive. <P>COPYRIGHT: (C)2006,JPO&NCIPI |
