Abstract: An adaptive lock position circuit includes a jitter distribution extremity detector and a phase shifting circuit. The jitter distribution extremity detector receives an input data signal and is operable to compare the input data signal with one or more clock signals derived from a recovered clock signal from a clock and data recovery (CDR) circuit to generate one or more control signals that define the boundaries of a jitter extremity detection window. The phase shifting circuit is coupled in a feedback loop with the jitter distribution extremity detector and receives the one or more control signals from the jitter distribution extremity detector and also receives the recovered clock signal. The phase shifting circuit is operable to shift the phase of the recovered clock signal as a function of the one or more control signals to generate a retiming clock signal such that an edge of the retiming clock signal is interpolated within the jitter extremity detection window.

Abstract: In accordance with the teachings described herein, systems and methods are provided for a precision adaptive equalizer. A variable gain equalizer may be used to apply a variable gain to an input signal to generate an equalized output signal. A phase and pattern detector circuit may be coupled in a feedback loop with the variable gain equalizer. The phase and pattern detector circuit may be used to identify a high frequency data pattern in the equalized output signal and compare the high frequency data pattern with a clock signal to detect a high frequency phase error. The phase and pattern detector circuit may be further operable to generate an automatic gain control signal as a function of the high frequency phase error, the automatic gain control signal being fed back to the variable gain equalizer to control the variable gain applied to the input signal.

Abstract: In accordance with the teachings described herein, systems and methods are provided for automatically correcting duty cycle distortion. A slicer may be used to receive a data input signal and compare the data input signal with a slicer offset voltage to generate a sliced data signal. The slicer may also receive an offset control signal to automatically adjust the slicer offset voltage. A phase detector may be used to receive the sliced data signal and a recovered clock signal and to compare the sliced data signal with the recovered clock signal to generate a rising edge output signal and a falling edge output signal. The rising edge output signal may correspond to a phase difference between a rising edge of the sliced data signal and an edge of the recovered clock signal. The falling edge output signal may correspond to a phase difference between a falling edge of the sliced data signal and an edge of the recovered clock signal.