Patent ID: 6542038
Filing Date: 2003-04-01
Classification: H03L

Abstract:
A PLL circuit for producing an output signal synchronized with a received reference signal, comprising:a phase comparator for comparing the reference signal and a comparison signal with each other in terms of a phase; a charge pump for producing a control voltage from an output of the phase comparator; a low pass filter for smoothing the control voltage; a voltage controlled oscillator (VCO) for producing an output having a frequency according to the smoothed control voltage; a phase-offset detecting phase comparator for comparing the reference signal and the output of the VCO in terms of a phase to detect phase offset, and producing first and second delay control signals corresponding to the phase offset; a first delay element for adding delay to the output of the VCO by the first delay control signal to produce the comparison signal; and a second delay element for adding delay to the output of the VCO by the second delay control signal to produce the output signal.