Audio Codec Feedback Circuit for Harmonic Distortion Compensation

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Solution Overview

Problem

Audio CODECs face challenges in achieving high sound quality due to harmonic distortion, which blurs sounds and degrades overall audio quality, especially after processing through non-linear systems.

Innovation Solution

An audio CODEC circuit and method that includes a digital-to-analog conversion circuit, an amplifying circuit, and a mixing circuit to eliminate the main-tone component by feeding back harmonic distortion and noise, allowing for compensation of audio data to improve sound quality.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Power

If audio data is processed through non-linear systems (amplifying circuit), then the audio signal is amplified, but harmonic distortion is generated that degrades sound quality

Engineering Contradiction:

Improveaudio signal amplificationVSAvoidharmonic distortion

Core Design Contradiction:

PowerVSObject-generated harmful factors

Solution Approach 1:

The patent implements a feedback mechanism where the output audio signal is fed back through a mixing circuit that eliminates the main-tone component. This feedback path allows the system to detect harmonic distortion generated by the amplifying circuit and compensate for it by adjusting the original audio data, thereby resolving the contradiction between signal amplification and harmonic distortion generation

Inventive Principle:

Principle #23Feedback

Solution Approach 2:

The patent converts the harmful harmonic distortion into a useful feedback signal. By eliminating the main-tone component from the output signal and feeding it back, the system uses the harmonic distortion and noise that would normally degrade quality as information to adjust and compensate the original audio data, thereby improving sound quality

Inventive Principle:

Principle #22Blessing in disguise (Convert harm into benefit)

2Object-generated harmful factors

If feedback mechanism is added to eliminate main-tone component, then harmonic distortion is reduced, but device complexity increases

Engineering Contradiction:

Improveharmonic distortion suppressionVSAvoidCODEC circuit complexity

Core Design Contradiction:

Object-generated harmful factorsVSDevice complexity

Solution Approach 1:

The patent merges multiple functions into existing circuit components. The mixing circuit performs both the function of combining audio signals and the function of eliminating the main-tone component for feedback. The amplifying circuit simultaneously amplifies the audio signal and generates the feedback signal through its non-linear characteristics, reducing the need for separate dedicated circuits

Inventive Principle:

Principle #5Merging (Combining)

Data Source

PatentUS11018634B2Audio codec circuit and method for processing audio data

Publication Date: 2021.05.25 REALTEK SEMICON CORP

AI summary

A circuit includes a digital-to-analog conversion circuit, an amplifying circuit, a mixing circuit, and an analog-to-digital converter. The digital-to-analog conversion circuit is configured to receive and convert audio data in the digital domain and output audio data in the analog domain. The audio data includes a main-tone component. The amplifying circuit is configured to output an audio signal according to the audio data in the analog domain. The mixing circuit is configured to eliminate the main-tone component according to the audio data in the analog domain and the audio signal and to output a feedback signal. The analog-to-digital converter is configured to convert the feedback signal from the analog domain to the digital domain.