DAC Circuit Signal Level Stability Against Resistor Variations

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Solution Overview

Problem

The existing communication apparatuses face challenges in maintaining signal levels due to environmental factors affecting resistor resistances, leading to changes in signal current amounts, which are not easily compensated by equivalent impedance changes in transmission channels.

Innovation Solution

A digital to analog conversion (DAC) circuit with a primary conversion circuit and first and second hybrid conversion circuits, operating with currents that include a constant and variable part, respectively, to adapt to resistor changes while maintaining signal levels through voltage drops across reception resistors.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If resistors are used to transmit signals in transmitter and receiver circuits, then signal transmission and reception are enabled, but signal levels become difficult to maintain due to environmental changes affecting resistor resistance

Engineering Contradiction:

Improvesignal level stabilityVSAvoidresistance change adaptability

Core Design Contradiction:

ReliabilityVSAdaptability or versatility

Solution Approach 1:

The patent changes the operating parameters of the DAC circuits based on detected resistance values. When resistance changes are detected in transmission or reception resistors, the reference voltages or current parameters of the DAC circuits are adjusted accordingly to compensate for the resistance changes and maintain stable signal levels.

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent implements feedback mechanisms where resistance detection circuits continuously monitor the resistance values of transmission and reception resistors. The detected resistance information is fed back to control circuits that adjust the DAC operating parameters, creating a closed-loop system that automatically compensates for resistance variations and maintains signal stability.

Inventive Principle:

Principle #23Feedback

2Stability of the object's composition

If environmental factors affect resistor resistance, then resistor values change, but equivalent impedance of transmission channel remains relatively stable

Engineering Contradiction:

Improveequivalent impedance stabilityVSAvoidsignal current stability

Core Design Contradiction:

Stability of the object's compositionVSReliability

Solution Approach 1:

The patent introduces resistance detection circuits and control circuits as intermediary elements between the resistors and the signal transmission path. These intermediary circuits detect resistance changes and mediate compensation by adjusting DAC parameters, thereby isolating the signal transmission from the direct impact of resistance variations while maintaining compatibility with the stable equivalent impedance of the transmission channel.

Inventive Principle:

Principle #24Intermediary (Mediator)

3Reliability

If resistor resistance changes due to environmental factors, then signal current amounts change, but signal transmission level needs to be maintained

Engineering Contradiction:

Improvesignal transmission levelVSAvoidenvironmental factor sensitivity

Core Design Contradiction:

ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent converts the harmful effect of resistance changes into a useful signal by using resistance detection circuits to detect the resistance variations. The detected resistance information is then used to adjust DAC parameters in a way that transforms the previously harmful resistance changes into an opportunity for automatic compensation, thereby maintaining stable signal transmission levels despite environmental variations.

Inventive Principle:

Principle #22Blessing in disguise (Convert harm into benefit)

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

The solution effectively maintains signal transmission levels by compensating for resistor changes due to environmental factors, ensuring consistent signal quality despite resistive variations, and balancing internal resistor effects with unchanged equivalent impedance.

Implementation Method 1

transmit the first reference transmission signal to a first reception resistor disposed between a receiver circuit and the signal transmission path to generate a voltage drop

Methodology Applied

Scientific EffectVoltage drop: Ohm's Law

Data Source

PatentUS11133961B2Communication apparatus and digital to analog conversion circuit thereof

Publication Date: 2021.09.28 REALTEK SEMICON CORP

AI summary

The present disclosure discloses a communication apparatus including a receiver circuit and a transmitter circuit having a signal processing circuit and a DAC circuit having a primary conversion circuit and a first hybrid conversion circuit. The primary conversion circuit converts and transmits a transmission signal from the signal processing circuit to a signal transmission path. The first hybrid conversion circuit converts the transmission signal to a first receiver resistor to generate a voltage drop. The receiver circuit receives a first actual receiving signal through the signal transmission path and the first receiver resistor. The primary conversion circuit operates according to a first current including a first and a second part currents and the first hybrid conversion circuit operates according to a second current. The first part current does not change according to a resistive change. The second part current and the second current change according to the resistive change.