Voltage Mode Driver Calibration for Stable De-Emphasis Levels

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Solution Overview

Problem

Voltage mode drivers in communication systems face challenges in maintaining acceptable de-emphasis levels due to process variations, leading to unacceptable emphasis levels and increased termination design complexity.

Innovation Solution

The implementation of a calibration system for voltage mode drivers that adjusts VMD cells using a calibration component to compensate for voltage dependence effects, ensuring calibrated output levels that meet specified de-emphasis requirements.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If voltage mode drivers are used to perform voltage mode signalling schemes, then communication reliability is improved through de-emphasis techniques, but process variations cause unacceptable emphasis levels and increased termination design complexity

Engineering Contradiction:

Improvecommunication reliabilityVSAvoidtermination design complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The patent applies parameter changes by dynamically adjusting the de-emphasis level through calibration. A calibration component modifies the operating parameters of the voltage mode driver cells to compensate for process variations, ensuring acceptable emphasis levels without increasing termination design complexity. The calibration process adjusts voltage or current parameters to achieve the desired de-emphasis effect despite manufacturing variations.

Inventive Principle:

Principle #35Parameter changes

2Reliability

If de-emphasis techniques are implemented to facilitate communication reliability, then distorted signals are corrected, but process variations lead to unacceptable emphasis levels

Engineering Contradiction:

Improvecommunication reliabilityVSAvoidemphasis level precision

Core Design Contradiction:

ReliabilityVSManufacturing precision

Solution Approach 1:

The patent implements feedback through a calibration system that measures the actual emphasis levels and adjusts the driver parameters accordingly. The calibration component receives feedback about the deviation from target emphasis levels and modifies the operating parameters to correct the deviation, ensuring manufacturing precision is achieved despite process variations.

Inventive Principle:

Principle #23Feedback

Solution Approach 2:

The patent applies preliminary action by performing calibration before normal operation to pre-adjust the driver parameters. The calibration component sets the appropriate de-emphasis levels in advance, compensating for process variations before they affect communication reliability. This preliminary calibration ensures that the driver operates at the correct emphasis levels from the start.

Inventive Principle:

Principle #10Preliminary action

Data Source

PatentUS8742799B2Systems and methods for de-emphasis level calibration in voltage mode drivers

Publication Date: 2014.06.03 TAIWAN SEMICONDUCTOR MANUFACTURING CO LTD

AI summary

A voltage mode driver circuit includes a plurality of VMD cells and a calibration component. The plurality of VMD cells are configured to generate a calibrated emphasis level according to a calibration signal. The calibration component is configured to determine a voltage dependence effect. Additionally, the calibration component is configured to generate the calibration signal according to the determined voltage dependence effect.