Ring Delay Line A/D Conversion With Temperature Compensation

Solution Overview

Problem

Existing A/D converter circuits face challenges in suppressing variations in digital data due to ambient temperature changes, requiring complex arithmetic processing that is not suitable for high-speed conversion and increasing production costs with the use of GaAs devices.

Innovation Solution

The proposed A/D converter circuit employs two pulse circulating circuits with counters to count pulse signal circulations, using a reference voltage to output digital data that cancels out temperature-induced variations, eliminating the need for complex arithmetic processing.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If complex arithmetic processing is used to correct temperature variations, then measurement precision is improved, but device complexity increases and productivity decreases

Engineering Contradiction:

Improvedigital data accuracyVSAvoidarithmetic processing circuit

Core Design Contradiction:

Measurement precisionVSDevice complexity

Solution Approach 1:

The patent creates a reference pulse circulating circuit that copies the structure and temperature characteristics of the measurement circuit. By measuring the reference circuit's pulse circulation time under the same temperature conditions and using it to correct the measurement data, the system achieves temperature compensation without complex arithmetic processing, thus resolving the contradiction between measurement precision and device complexity

Inventive Principle:

Principle #26Copying

Solution Approach 2:

The patent introduces a reference voltage signal and reference pulse circulating circuit as intermediaries between the temperature variations and the measurement system. The reference circuit acts as a mediator that captures temperature effects and transmits this information to the correction mechanism, enabling simple temperature compensation while maintaining measurement accuracy

Inventive Principle:

Principle #24Intermediary (Mediator)

2Measurement precision

If complex arithmetic processing is used to correct temperature variations, then measurement precision is improved, but productivity decreases due to extended processing time

Engineering Contradiction:

Improvedigital data accuracyVSAvoidA/D conversion speed

Core Design Contradiction:

Measurement precisionVSProductivity

Solution Approach 1:

The patent creates a reference pulse circulating circuit that copies the structure and temperature characteristics of the measurement circuit. By measuring the reference circuit's pulse circulation time under the same temperature conditions and using it to correct the measurement data, the system achieves temperature compensation without complex arithmetic processing, thus resolving the contradiction between measurement precision and device complexity

Inventive Principle:

Principle #26Copying

Solution Approach 2:

The patent enables continuous A/D conversion by implementing temperature compensation through parallel reference measurements rather than sequential arithmetic corrections. The reference pulse circulating circuit operates continuously alongside the measurement circuit, allowing immediate correction of temperature effects without extending conversion time, thereby maintaining high productivity

Inventive Principle:

Principle #20Continuity of useful action

3Productivity

If GaAs devices are used for high-speed arithmetic processing, then productivity is improved, but manufacturing precision requirements increase and cost increases

Engineering Contradiction:

Improvearithmetic operation speedVSAvoidsemiconductor production

Core Design Contradiction:

ProductivityVSManufacturing precision

Solution Approach 1:

The patent creates a reference pulse circulating circuit that copies the structure and temperature characteristics of the measurement circuit. By measuring the reference circuit's pulse circulation time under the same temperature conditions and using it to correct the measurement data, the system achieves temperature compensation without complex arithmetic processing, thus resolving the contradiction between measurement precision and device complexity

Inventive Principle:

Principle #26Copying

Solution Approach 2:

The patent replaces expensive GaAs devices with standard semiconductor components by implementing temperature compensation through the reference pulse circulating circuit approach. This substitution uses conventional, cost-effective materials and manufacturing processes while achieving the same functional outcome, thereby resolving the contradiction between productivity and manufacturing precision requirements

Inventive Principle:

Principle #27Cheap short-living objects (Disposable)

Data Source

PatentUS7639169B2A/D converter circuit and A/D conversion method

Publication Date: 2009.12.29 DENSO CORP

AI summary

An A/D converter circuit has a first ring delay line and a second ring delay line configured to vary respective characteristics in the same manner relative to a change in the ambient temperature. A reference voltage, which is free from a change in temperature, is fed as a power supply voltage to the second ring delay line. Digital data produced by the first ring delay line is temperature-compensated by digital data produced by the second ring delay line.