US 9,917,607 B1 · Baseline wander correction gain adaptation

Abstract

Embodiments include systems and methods for baseline wander correction gain adaptation in receiver circuits. Some embodiments operate in context of an alternating current coupled transceiver communicating data signals over a high-speed transmission channel, such that the receiver system includes an AC-coupled data input and a feedback loop with a data slicer and an error slicer. A baseline wander correction (BWC) circuit can be part of the feedback loop and can generate a feedback signal corresponding to low-pass-filtered bits data from the data slicer output and having a gain generated according to pattern-filtered error data from the error slicer output. For example, gain adaptation is performed according to error information corresponding to a detected relatively high-frequency data pattern following a long low-frequency pattern.

Claims24

Dependent claims

A receiver system comprising:

an alternating current coupled (AC-coupled) data input;
a summer circuit coupled with the AC-coupled data input and a feedback input and having a summer output, the summer output generated according to a sum of the AC-coupled data input and the feedback input;
a feedback circuit coupled with the summer output and having a data slicer output and an error slicer output, the data slicer output comprising data samples generated according to the summer output, and the error slicer output comprising error samples generated according to the summer output;
and
a baseline wander correction (BWC) circuit coupled with the data slicer output and the error slicer output, and having a feedback output coupled with the feedback input, the feedback output having a gain adapted as a function of gain error data temporally corresponding to a detected data pattern, the gain error data derived from the error slicer output, and the detected data pattern derived from the data slicer output.

2 more elements

A method for baseline wander correction gain adaptation, the method comprising:

detecting, in a receiver system coupled with a data channel, a predefined data pattern as having a higher-frequency pattern of data bits immediately following a lower-frequency pattern of data bits, the lower frequency pattern of data bits being at least a predetermined length, and the data bits derived from a data sampler of the receiver system;
and
generating a gain adaptation output as a function of gain error data accumulated over a voting window triggered according to the detecting, the gain error data being derived from an error sampler of the receiver system,
wherein the data channel is an AC-coupled data channel having a characteristic AC pole frequency;
wherein the data bits are derived from a data signal received via the data channel;
and
wherein the detecting comprises low-pass filtering the data signal according to a low-frequency pole that substantially matches the AC pole frequency.

4 more elements

A method for baseline wander correction gain adaptation, comprising:

detecting, in a receiver system coupled with a data channel, a predefined data pattern as having a higher-frequency pattern of data bits immediately following a lower-frequency pattern of data bits, the lower frequency pattern of data bits being at least a predetermined length, and the data bits derived from a data sampler of the receiver system;
and
generating a gain adaptation output as a function of gain error data accumulated over a voting window triggered according to the detecting, the gain error data being derived from an error sampler of the receiver system,
wherein the detecting the predefined data pattern comprises:
generating a plurality of DAC codes, each characterizing a corresponding string of N consecutive data bits according to its proportion of matching data bits;
generating a pattern trigger in response to detecting that each of at least a predetermined run length of the plurality of DAC codes comprises at least a threshold proportion of the matching bits, the matching bits having a common bit value for all the predetermined run length of the plurality of DAC codes;
and
triggering the voting window according to the pattern trigger.

5 more elements

Dependencies are inferred from the claim text.

Baseline wander correction gain adaptation

Life of this patent

Baseline wander correction gain adaptation

Life of this patent

Abstract

Claims24