Timing extraction circuit

摘要

A timing extraction circuit includes a phase comparator, a charge pump circuit, a filter circuit and a voltage controlled oscillator, these components constituting a phase-locked loop. The phase comparator compares the phases of a digital data signal and a timing signal and supplies first and second difference signals to the charge pump circuit. The charge pump circuit detects a phase error corresponding to the difference between the integrals of the first and second difference signals. The filter circuit supplies a control signal corresponding to the phase error to the voltage controlled oscillator. The voltage controlled oscillator generates the timing signal having a period corresponding to the control signal.