Voltage-Mode FFE Transmitter Control Without Driver Segmentation

Solution Overview

Problem

In wired communication, implementing a feed-forward equalizer (FFE) with a voltage-mode driver requires segmentation into multiple cell drivers, which reduces output bandwidth and increases power consumption, affecting the transmitter's maximum bandwidth and efficiency.

Innovation Solution

Integrating FFE coefficient control into an impedance control loop within a control circuit, eliminating the need for segmentation of the driver into multiple cell drivers, allowing for FFE coefficient adjustment and output impedance correction while reducing the number of cell drivers from 567 to 9, thereby optimizing bandwidth and energy efficiency.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If the transmitter is segmented into several cell drivers to implement FFE functions, then the FFE coefficient control is achieved, but the output bandwidth is reduced and power consumption increases

Engineering Contradiction:

ImproveFFE coefficient resolutionVSAvoidoutput bandwidth

Core Design Contradiction:

Measurement precisionVSSpeed

Solution Approach 1:

The patent merges the FFE coefficient control function with the impedance control loop, allowing a single driver structure to perform both functions simultaneously. This integration eliminates the need for separate cell driver segments, thereby maintaining full output bandwidth while achieving precise FFE coefficient control through the unified control mechanism.

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The driver circuit is designed to perform multiple functions: both impedance control and FFE coefficient adjustment. By making the driver universal, the patent eliminates the need for specialized cell drivers, preserving the full bandwidth capability while enabling precise equalization control through the multi-functional control circuit.

Inventive Principle:

Principle #6Universality (Multi-functionality)

2Measurement precision

If the transmitter is segmented into several cell drivers to implement FFE functions, then the FFE coefficient control is achieved, but the power consumption increases

Engineering Contradiction:

ImproveFFE coefficient resolutionVSAvoidpower consumption

Core Design Contradiction:

Measurement precisionVSUse of energy by moving object

Solution Approach 1:

The patent merges the FFE coefficient control function with the impedance control loop, allowing a single driver structure to perform both functions simultaneously. This integration eliminates the need for separate cell driver segments, thereby maintaining full output bandwidth while achieving precise FFE coefficient control through the unified control mechanism.

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The driver circuit is designed to perform multiple functions: both impedance control and FFE coefficient adjustment. By making the driver universal, the patent eliminates the need for specialized cell drivers, preserving the full bandwidth capability while enabling precise equalization control through the multi-functional control circuit.

Inventive Principle:

Principle #6Universality (Multi-functionality)

3Adaptability or versatility

If the transmitter is segmented into several cell drivers, then the FFE functions are implemented, but the number of drivers increases from 9 to 567

Engineering Contradiction:

ImproveFFE functionalityVSAvoidnumber of cell drivers

Core Design Contradiction:

Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent merges the FFE coefficient control function with the impedance control loop, allowing a single driver structure to perform both functions simultaneously. This integration eliminates the need for separate cell driver segments, thereby maintaining full output bandwidth while achieving precise FFE coefficient control through the unified control mechanism.

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The driver circuit is designed to perform multiple functions: both impedance control and FFE coefficient adjustment. By making the driver universal, the patent eliminates the need for specialized cell drivers, preserving the full bandwidth capability while enabling precise equalization control through the multi-functional control circuit.

Inventive Principle:

Principle #6Universality (Multi-functionality)

Data Source

PatentUS12034574B1Feed-forward equalizer and voltage-mode signal transmitter using same

Publication Date: 2024.07.09 NATIONAL TSING HUA UNIVERSITY

AI summary

A feed-forward equalizer (FFE) and a voltage-mode signal transmitter using the same are provided. The FFE includes an output, a plurality of tap drivers, and a control circuit. Each tap driver includes a cell driver. The control circuit includes a FFE control loop and an impedance control loop. The FFE control loop includes a first replica circuit corresponding to a part of the cell drivers. The FFE control loop generates at least one first reference voltage according to the first replica circuit. The impedance control loop includes a second replica circuit corresponding to the cell drivers in the tap drivers. The impedance control loop generates at least one second reference voltage according to the first reference voltage and the second replica circuit. The tap drivers are controlled by the first and second reference voltages to adjust respective output impedance thereof.