DAC Signal Calibration Using Staged Echo-Canceling Training

Solution Overview

Problem

The interaction among calibration circuits in DAC circuits complicates the training process, making it difficult to achieve effective calibration and echo-canceling.

Innovation Solution

A digital-to-analog conversion apparatus and method that includes multiple conversion circuits, calibration circuits, and a calibration parameter calculating circuit, which perform signal processing and mapping using offset tables and response coefficients to generate calibration signals and offsets, allowing for staged training to avoid circuit interaction.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If multiple calibration circuits are included in the DAC circuit to improve calibration precision, then the calibration precision is improved, but the training difficulty increases due to circuit interaction

Engineering Contradiction:

Improvecalibration precisionVSAvoidtraining difficulty

Core Design Contradiction:

Measurement precisionVSDevice complexity

Solution Approach 1:

The calibration process is segmented into multiple stages: a first training stage where only the first calibration circuit is trained with the first conversion circuit enabled and second conversion circuit disabled, and a second training stage where only the second calibration circuit is trained with the first conversion circuit disabled and second conversion circuit enabled. This segmentation eliminates mutual interference between calibration circuits during training while maintaining both calibration circuits for improved calibration precision during actual operation.

Inventive Principle:

Principle #1Segmentation

2Measurement precision

If multiple calibration circuits are included in the DAC circuit to improve calibration precision, then the calibration precision is improved, but the device complexity increases

Engineering Contradiction:

Improvecalibration precisionVSAvoidcircuit complexity

Core Design Contradiction:

Measurement precisionVSDevice complexity

Solution Approach 1:

The calibration process is segmented into multiple stages: a first training stage where only the first calibration circuit is trained with the first conversion circuit enabled and second conversion circuit disabled, and a second training stage where only the second calibration circuit is trained with the first conversion circuit disabled and second conversion circuit enabled. This segmentation eliminates mutual interference between calibration circuits during training while maintaining both calibration circuits for improved calibration precision during actual operation.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent applies preliminary action by performing staged training of calibration circuits before actual DAC operation. The first calibration circuit is trained first using predetermined training data, followed by training of the second calibration circuit. This preliminary staged training establishes proper calibration parameters for each circuit before they are both activated, reducing the complexity of coordinating multiple calibration circuits during normal operation.

Inventive Principle:

Principle #10Preliminary action

3Ease of operation

If staged training is implemented to reduce training difficulty, then the training process becomes easier, but the training time increases

Engineering Contradiction:

Improvetraining easeVSAvoidtraining time

Core Design Contradiction:

Ease of operationVSLoss of time

Solution Approach 1:

The calibration process is segmented into multiple stages: a first training stage where only the first calibration circuit is trained with the first conversion circuit enabled and second conversion circuit disabled, and a second training stage where only the second calibration circuit is trained with the first conversion circuit disabled and second conversion circuit enabled. This segmentation eliminates mutual interference between calibration circuits during training while maintaining both calibration circuits for improved calibration precision during actual operation.

Inventive Principle:

Principle #1Segmentation

Data Source

PatentUS11784654B2Digital-to-analog conversion apparatus and method having signal calibration mechanism

Publication Date: 2023.10.10 REALTEK SEMICON CORP

AI summary

The present invention discloses a DAC method having signal calibration mechanism. A first conversion circuit generates a first analog signal according to an input digital signal. A second conversion circuit generates a second analog signal according to the input digital signal and a pseudo-noise digital signal. An echo transmission circuit processes a signal on an echo path to generate an echo signal. A first and a second calibration circuits generate a first and a second calibration signals. A calibration parameter calculation circuit performs calculation according to a difference between the echo signal and a sum of the first and the second calibration signals and related path information to generate a first and a second offsets. The first and the second calibration circuits converge first and second response coefficients and update a first and a second codeword offset tables according to the first and the second offsets.