| 摘要 |
A phase-locked loop includes: a voltage-controlled oscillator (VCO) system receiving one or more control signals and in response thereto generating a PLL output signal; a plurality of phase detectors for comparing a reference signal having a reference frequency to a PLL feedback signal having a PLL feedback frequency derived from the PLL output signal, and in response thereto to output a comparison signal; and a plurality of signal processing paths each connected to an output of a corresponding one of the phase detectors for outputting a phase detection output signal. The signal processing paths have different frequency responses from each other. In operation only one of the phase detectors is activated, and a switching arrangement selectively switches between outputs of the signal processing paths to select the phase detection output signal from the activated phase detector to generate the control signal(s) for the VCO system.
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