Analog Signal Coupling Circuit With Shared Reference Path

Solution Overview

Problem

Conventional signal coupling circuits require multiple pins and coupling capacitors for each input signal and its corresponding reference signal, leading to increased circuit cost and complexity as the number of input signals grows.

Innovation Solution

A signal coupling method and circuit that utilizes a common reference signal shared among multiple input signals, reducing the number of pins and coupling capacitors by using a single coupling unit for the reference signal and separate units for the input signals, with multiplexers to select and transmit the appropriate signals to the processing circuit.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If separate reference signals are coupled for each input signal, then noise resistance is improved, but the number of device pins and coupling capacitors increases

Engineering Contradiction:

Improvenoise resistanceVSAvoidnumber of device pins

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The patent merges multiple separate reference signal coupling paths into a single shared reference signal path. Instead of providing separate reference signals ref_A, ref_B, ref_C for each input signal sig_A, sig_B, sig_C, the invention couples all processing circuits to a common reference signal through a single shared coupling capacitor, thereby reducing the number of device pins and external components while maintaining noise resistance through the common reference.

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The shared coupling capacitor and common reference signal pin serve multiple functions simultaneously - they provide the reference signal for all processing circuits (first processing circuit, second processing circuit, third processing circuit) through a single component, making the reference signal coupling path universal for all channels rather than dedicated to each individual channel.

Inventive Principle:

Principle #6Universality (Multi-functionality)

2Reliability

If separate reference signals are coupled for each input signal, then noise resistance is improved, but circuit cost increases

Engineering Contradiction:

Improvenoise resistanceVSAvoidcircuit cost

Core Design Contradiction:

ReliabilityVSEase of manufacture

Solution Approach 1:

The patent merges multiple separate reference signal coupling paths into a single shared reference signal path. Instead of providing separate reference signals ref_A, ref_B, ref_C for each input signal sig_A, sig_B, sig_C, the invention couples all processing circuits to a common reference signal through a single shared coupling capacitor, thereby reducing the number of device pins and external components while maintaining noise resistance through the common reference.

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The invention uses a single shared coupling capacitor to replicate the reference signal coupling function for multiple processing circuits simultaneously, rather than using separate physical capacitors for each circuit. This copying approach reduces component count and cost while maintaining the functional equivalence of separate coupling paths.

Inventive Principle:

Principle #26Copying

3Adaptability or versatility

If multiple coupling capacitors are used for reference signals, then each signal can be coupled independently, but the number of coupling capacitors increases

Engineering Contradiction:

Improvesignal coupling independenceVSAvoidnumber of coupling capacitors

Core Design Contradiction:

Adaptability or versatilityVSQuantity of substance

Solution Approach 1:

The patent merges multiple separate reference signal coupling paths into a single shared reference signal path. Instead of providing separate reference signals ref_A, ref_B, ref_C for each input signal sig_A, sig_B, sig_C, the invention couples all processing circuits to a common reference signal through a single shared coupling capacitor, thereby reducing the number of device pins and external components while maintaining noise resistance through the common reference.

Inventive Principle:

Principle #5Merging (Combining)

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 reduces the number of device pins and coupling capacitors, thereby decreasing circuit cost and complexity while maintaining noise resistance by using a common reference signal for multiple input signals.

Implementation Method 1

the ac component of the signal is usually coupled into the device in a capacitor coupling way

Methodology Applied

Scientific EffectCapacitor coupling: Capacitance

Data Source

PatentUS7586359B2Signal coupling circuit and method

Publication Date: 2009.09.08 XUESHAN TECH INC

AI summary

The invention provides a signal coupling circuit and method for coupling an analog input signal to a processing circuit. The signal coupling circuit includes a number of first coupling units, a second coupling unit and a first multiplexer. The first coupling units are coupled to a first input terminal of the processing circuit, for respectively receiving a plurality of input signals. The first multiplexer is coupled between the first coupling units and the processing circuit for selecting one of the input signals and transmitting the selected input signal to the processing circuit. The second coupling unit is coupled to a second input terminal of the processing circuit, for receiving a common reference signal, wherein the processing circuit uses the common reference signal as reference for processing some or all of the input signals.