Systems and methods for correcting gain error due to transition density variation in clock recovery systems

摘要

In one embodiment, the present invention is directed to a system for processing a data stream. The system comprises: a voltage controlled oscillator (VCO) that generates a VCO signal in response to a tuning signal; a phase detector that generates an error signal that is indicative of a phase difference between a data signal and the VCO signal; a first filter that filters a reference signal that is indicative of an occurrence of a data transition; a second filter that filters the error signal, wherein the first filter and second filter are low-pass filters that possess a bandwidth that approximately equals one half of the reciprocal of: a unit interval multiplied by a maximum run length; and a divider circuit that divides the filtered error signal by the filtered reference signal.