Multiplexed Integrating Amplifier for Low-Power LOS Detection

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Solution Overview

Problem

Existing loss of signal (LOS) circuits in semiconductor devices require significant space and electrical current due to the need for two identical amplifiers to compare the main data signal with a reference signal without interrupting the data stream, leading to increased circuit footprint and reduced performance.

Innovation Solution

A multiplexed integrating amplifier (MIALOS) system that time-multiplexes the use of a single amplifier between the data signal and a reference signal, allowing for parallel operation with the main data path and reducing the overall circuit size and current draw by eliminating the need for a second identical amplifier.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If two identical amplifiers are used to compare the main data signal with a reference signal without interrupting the data stream, then loss of signal detection accuracy is improved, but circuit footprint and current draw increase significantly

Engineering Contradiction:
Improveloss of signal detection accuracyVSAvoidcircuit footprint
Core Design Contradiction:
Measurement precisionVSArea of stationary object

Solution Approach 1:

The patent combines the functions of two separate amplifiers into a single amplifier by time-multiplexing the reference signal and data signal through a multiplexer. The single amplifier alternates between amplifying the reference signal and the data signal, eliminating the need for two identical amplifiers while maintaining detection accuracy through periodic comparison.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The single amplifier is designed to perform multiple functions by processing both the reference signal and the data signal at different time intervals. This multi-functional approach allows the amplifier to serve both as a reference signal amplifier and a data signal amplifier, reducing the overall component count and circuit footprint.

Inventive Principle:
Principle #6Universality (Multi-functionality)

2Reliability

If two identical amplifiers are used to compare the main data signal with a reference signal, then loss of signal detection reliability is improved, but electrical current consumption increases dramatically

Engineering Contradiction:
Improveloss of signal detection reliabilityVSAvoidcurrent draw
Core Design Contradiction:
ReliabilityVSUse of energy by stationary object

Solution Approach 1:

The patent merges the current consumption of two amplifiers into a single amplifier by time-sharing its operation. The amplifier processes the reference signal during one time interval and the data signal during another, reducing the total current draw while maintaining the reliability needed for accurate loss of signal detection through periodic signal comparison.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The system employs periodic action by alternating between amplifying the reference signal and the data signal in time intervals. This periodic switching, controlled by the multiplexer, allows the single amplifier to maintain reliable detection capabilities while consuming less current than two continuously operating amplifiers would require.

Inventive Principle:
Principle #19Periodic action

3Productivity

If a second identical amplifier is provided for LOS comparison, then data stream continuity is maintained, but device complexity increases

Engineering Contradiction:
Improvedata stream continuityVSAvoidnumber of amplifiers
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The patent merges the functionality of two amplifiers into one by using a multiplexer to time-share the single amplifier between reference signal processing and data signal processing. This reduces the number of amplifiers from two to one, simplifying the device while maintaining data stream continuity through non-intrusive monitoring.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The multiplexer acts as an intermediary that directs the reference signal and data signal to the single amplifier at appropriate time intervals. This intermediary component enables the single amplifier to handle multiple signal types without requiring two separate amplifiers, thereby reducing device complexity while preserving continuous data stream processing.

Inventive Principle:
Principle #24Intermediary (Mediator)

Data Source

PatentEP3614582B1Multiplexed integrating amplifier for loss of signal detection
Publication Date: 2022.02.23 SEMTECH CORP
  • EP3614582B1 patent drawingFigure 1A~2A
  • EP3614582B1 patent drawingFigure 2B
  • EP3614582B1 patent drawingFigure 2C

AI summary

A loss of signal circuit has a multiplexer and a photodiode coupled to a first input of the multiplexer. A reference signal generator is coupled to a second input of the multiplexer. An amplifier is coupled to an output of the multiplexer. A demultiplexer includes an input of the demultiplexer coupled to an output of the amplifier. A first capacitor is coupled to a first output of the demultiplexer. A second capacitor is coupled to a second output of the demultiplexer. A comparator has a first input coupled to the first output of the demultiplexer and a second input of the comparator is coupled to the second output of the demultiplexer.