Timing signal recovery circuit for a data transmission system

摘要

A timing signal recovery circuit for recovering a timing signal from a received signal includes a circuit for extracting a timing signal from the received signal; a voltage-controlled oscillator (VCO) to generate a local timing signal; a phase-difference detecting circuit for detecting a phase difference between the extracted timing signal and the local timing signal; a loop filter responsive to the detected phase difference for generating a VCO control voltage supplied to the VCO; and a circuit for controlling the loop filter such that the VCO control voltage remains substantially within a predetermined voltage range. The loop filter control circuit substantially prevents instability of the VCO.