Line Driver Power Efficiency via Dynamic Voltage Switching

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Solution Overview

Problem

The power consumption of line drivers in DSL communications systems remains high due to the use of high dynamic range voltage supplies, which are necessary to amplify both low and high signal peaks without distortion, leading to increased energy usage despite advancements in semiconductor technology.

Innovation Solution

A dual channel line driver system that switches between low and high voltage power supply rails based on signal peak amplitude, using a charge pump to adjust the voltage only when high peaks are detected, thereby reducing overall power consumption by minimizing the use of high voltage and optimizing power efficiency.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If high dynamic range voltage supplies are used to amplify both low and high signal peaks without distortion, then signal quality is improved, but power consumption increases

Engineering Contradiction:
Improvesignal qualityVSAvoidpower consumption
Core Design Contradiction:
ReliabilityVSUse of energy by moving object

Solution Approach 1:

The patent implements dynamic voltage switching that adapts the power supply voltage based on the instantaneous signal amplitude. The line driver switches between high voltage (for high signal peaks) and low voltage (for low signal levels) to match the actual signal requirements, thereby maintaining signal quality while reducing power consumption during low-amplitude periods

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The invention changes the voltage parameter dynamically by detecting signal peak amplitude and adjusting the power supply voltage accordingly. When signal peaks exceed a threshold, high voltage is applied; when peaks remain below the threshold, low voltage is used, thus optimizing the balance between signal fidelity and energy efficiency

Inventive Principle:
Principle #35Parameter changes

2Reliability

If high voltage is used continuously to ensure adequate amplification headroom, then signal distortion is prevented, but energy efficiency deteriorates

Engineering Contradiction:
Improvesignal distortion preventionVSAvoidenergy efficiency
Core Design Contradiction:
ReliabilityVSLoss of energy

Solution Approach 1:

The patent employs a peak detector that monitors signal amplitude in advance and triggers voltage switching before distortion can occur. By detecting peaks ahead of time and pre-switching to high voltage when needed, the system prevents signal distortion while avoiding unnecessary high-voltage operation during low-amplitude periods, thus improving energy efficiency

Inventive Principle:
Principle #10Preliminary action

3Use of energy by moving object

If voltage switching is implemented to reduce power consumption, then energy efficiency is improved, but system complexity increases

Engineering Contradiction:
Improveenergy efficiencyVSAvoidsystem complexity
Core Design Contradiction:
Use of energy by moving objectVSDevice complexity

Solution Approach 1:

The patent introduces a peak detector as an intermediary component that simplifies the control logic for voltage switching. Instead of requiring complex real-time analysis of signal characteristics, the peak detector provides a simple threshold-based control signal that triggers voltage transitions, thereby achieving energy efficiency improvements while keeping the added complexity manageable

Inventive Principle:
Principle #24Intermediary (Mediator)

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

This approach significantly reduces the power consumption of the line driver by using low voltage for most of the transmission time and activating the charge pump only for high signal peaks, resulting in improved power efficiency and reduced energy usage.

Implementation Method 1

a charge pump, wherein the charge pump adjusts a voltage level of a power supply rail from a first level to a second level in response to a control signal

Methodology Applied
Scientific EffectCharge pump voltage conversion:

Data Source

PatentEP2955890B1Improving power efficiency of a line driver
Publication Date: 2017.06.14 HUAWEI TECH CO LTD
  • EP2955890B1 patent drawingFigure 1
  • EP2955890B1 patent drawingFigure 2
  • EP2955890B1 patent drawingFigure 3

AI summary

An line driver including a delay circuit, a DAC, a filter circuit, a peak predictor, a peak detector; and a control interface logic; the line driver further comprising a long timing delay circuit and a short timing delay circuit; wherein the filter circuit is configured to amplify an analog signal, and wherein the long timing delay circuit and a short timing delay circuit may be coupled in parallel to the peak detector and a control interface logic; the long timing delay circuit and the short timing delay circuit introduce a relatively long time delay and a relatively short delay, respectively, to signal on a control path.