Digital Gain Correction Circuit for Low-Frequency Distortion
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Solution Overview
Problem
Existing data processing systems, such as perpendicular recording systems, face challenges in effectively mitigating low frequency gain distortion due to fly height variation, which analog gain control loops are unable to adequately address.
Innovation Solution
The implementation of a post processing gain correction system that includes a data detector circuit, filter circuit, gain error generation circuit, and multiplier circuit, operating in the digital domain to calculate and apply a gain feedback value for correcting gain distortion, with error accumulation and reliability filtering to enhance data processing accuracy.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If an analog gain control loop is used to correct low frequency gain distortion, then the system structure is simple, but the gain distortion correction effectiveness is insufficient
Solution Approach 1:
The patent replaces the analog gain control loop (mechanical/electrical system) with a digital post-processing gain correction system that operates on detected data. The digital system calculates gain errors based on detected output and applies corrections through multiplication, achieving superior correction effectiveness while maintaining reasonable complexity.
Solution Approach 2:
The patent performs gain error calculation and correction preparation in advance by analyzing the relationship between detected output and filtered output, then applies the pre-calculated gain feedback value to correct the data. This preliminary analysis enables more accurate correction compared to continuous analog adjustment.
2Reliability
If digital post processing gain correction is implemented, then gain distortion correction effectiveness is improved, but device complexity increases
Solution Approach 1:
The patent merges the gain correction function with the existing data detection and filtering processes. The gain error generation circuit utilizes the detected output and filtered output that are already being processed in the system, combining multiple functions into an integrated digital correction approach rather than adding a completely separate system.
Solution Approach 2:
The digital post-processing gain correction system uses the system's own detected output and filtered output to calculate the gain error and generate the feedback value. The system self-corrects by utilizing its internal signals, eliminating the need for external calibration equipment or additional sensing mechanisms.
3Measurement precision
If error accumulation and reliability filtering are applied, then data processing accuracy is improved, but processing time increases
Solution Approach 1:
The patent applies reliability filtering selectively based on confidence thresholds rather than processing all data points with equal computational effort. When the reliability indicator exceeds the threshold, the system uses the full error accumulation calculation; otherwise, it may use simplified processing, achieving high accuracy for critical data while reducing overall processing time.
Data Source
AI summary
Various embodiments of the present invention provide circuits, systems and methods for data processing. For example, a data processing system is disclosed that includes: a data detector circuit, a filter circuit, a gain error generation circuit, and a multiplier circuit. The data detector circuit is operable to apply a data detection algorithm to a data set to yield a detected output. The filter circuit is operable to filter the detected output to yield a filtered output. The gain error generation circuit is operable to calculate an error value based upon a combination of an instance of the data set and a corresponding instance of the filtered output. The multiplier circuit operable to multiply the instance of the data set by a gain feedback value to yield a gain corrected output. The gain feedback value is derived from the error value.