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Phase-locked loop circuit, semiconductor integrated circuit, electronic device, and control method of phase-locked loop circuit

  • US 20110215875A1
  • Filed: 02/15/2011
  • Published: 09/08/2011
  • Est. Priority Date: 03/08/2010
  • Status: Active Grant
First Claim
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1. A phase-locked loop circuit comprising:

  • a phase and frequency comparing section configured to compare a phase of an external reference clock signal with a phase of a comparison clock signal, and generate an error signal corresponding to a result of comparison;

    an oscillating section configured to generate an internal clock signal of an oscillation frequency corresponding to said error signal;

    a frequency dividing section configured to generate said comparison clock signal by frequency-dividing said internal clock signal by a predetermined frequency dividing ratio;

    an oscillator control section configured to generate an oscillation control signal for controlling frequency of said internal clock signal output from said oscillating section on a basis of said error signal; and

    a frequency divider control section configured to generate a frequency division control signal for controlling a bias current of said frequency dividing section on a basis of said error signal;

    wherein said oscillator control section and said frequency divider control section are configured such that said oscillation control signal and said frequency division control signal respond having a predetermined relation to each other on a basis of said error signal both in a pull-in process and at a time of locking.

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