Method and apparatus for offset and gain correction
AssigneeMarvell World Trade Ltd.
InventorsJin XIE, Bin Ni, Mats Oberg
Life of this patent
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Abstract
Aspects of the disclosure provide a signal processing circuit that has fast response time to sudden profile changes in an electrical signal. The signal processing circuit includes a processing path configured to process an electrical signal that is generated in response to reading data on a storage medium, and a feed-forward correction module. The feed-forward correction module is configured to detect a profile variation based the electrical signal in a time window, and correct the electrical signal in the time window based on the detected profile variation.
Claims19
A read channel, comprising:
- a front-end processing circuit that receives an electrical signal and that includes a feedback control loop that corrects errors in the electrical signal:
- a feed-forward correction circuit that is configured to detect a profile variation of the electrical signal and that includes a feed-forward loop that corrects error in a delayed electrical signal;
- and
- a timing compensation circuit that feedbacks the corrected delayed electrical signal to the front-end processing circuit.
The read channel as recited in 2, wherein
- the feedback offset correction circuit and the feedback gain correction circuit are configured to compensate for offset errors and gain errors, respectively.
The read channel as recited in 1, wherein
- the feed-forward correction circuit detects the profile variation based on samples of the electrical signal in a time window, and correct a sample in the time window based on the detected profile variation.
The read channel as recited in 4, wherein
- the feed-forward correction circuit detects a center sample in the time window based on the detected profile variation.
The read channel as recited in 4, wherein
- the feed-forward correction circuit corrects the sample in the time window when the detected profile variation is larger than a threshold.
The read channel as recited in 6, wherein
- the feed-forward correction circuit corrects a number of samples following the sample in the time window when the detected profile variation is larger than the threshold.
The read channel as recited in 6, wherein
- the feed-forward correction circuit is configured to correct the sample in the time window when profile variations for a number of time windows are larger than the threshold.
A feed-forward correction circuit, comprising:
- an offset correction circuit that detects an offset variation based on samples of an electrical signal in a time window and generates an offset correction;
- a gain error correction circuit that detects an amplitude variation based on the samples of the electrical signal in the time window and generates a gain correction;
- a delay module that delays the electrical signal;
- and
- a multiplier that amplifies an addition of the offset correction and the delayed electrical signal based on the gain correction.
Dependencies are inferred from the claim text.