Multi-Comparator Test Apparatus for Noise-Resistant Signal Transition Detection

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Solution Overview

Problem

Conventional test apparatuses are sensitive to noise and timing jitter, leading to inaccurate detection of signal transitions due to their reliance on 1-bit information from comparators, making it difficult to improve measurement accuracy.

Innovation Solution

A test apparatus comprising multiple comparators with a common reference level and a signal processing section that generates a single result signal based on comparison results, utilizing stochastic sampling to produce multi-bit information for accurate signal comparison and edge timing detection.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If a single comparator is used to compare signal level to reference level, then the device complexity is low, but the measurement precision deteriorates due to sensitivity to noise and timing jitter

Engineering Contradiction:

Improvesignal transition detection accuracyVSAvoidcomparator quantity

Core Design Contradiction:

Measurement precisionVSDevice complexity

Solution Approach 1:

The single comparator function is segmented into multiple comparators (first comparator and second comparator) with different reference levels. Each comparator independently compares the signal to its own reference level, and their results are combined through logical operations to achieve more accurate transition detection that is less sensitive to noise and timing jitter.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The comparison results from multiple comparators are merged through a logical operation unit that performs logical AND operations on the comparison outputs. This combining of multiple independent comparison results produces a more reliable measurement that overcomes the limitations of single-comparator systems.

Inventive Principle:

Principle #5Merging (Combining)

2Loss of information

If 1-bit information from a single comparator is used, then the device complexity is low, but the loss of information increases, making it difficult to improve measurement accuracy

Engineering Contradiction:

Improvesignal characteristic informationVSAvoidsignal processing section complexity

Core Design Contradiction:

Loss of informationVSDevice complexity

Solution Approach 1:

The single 1-bit information output is segmented into multiple parallel comparison results, each containing different aspects of the signal characteristics. By maintaining multiple independent comparison outcomes rather than reducing to a single bit, the system preserves more information about the signal's relationship to reference levels.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The logical operation unit acts as an intermediary that processes multiple comparison results before producing the final output. This intermediary stage allows for sophisticated information processing that extracts meaningful signal characteristics while filtering out noise, thereby reducing information loss.

Inventive Principle:

Principle #24Intermediary (Mediator)

Data Source

PatentUS9213669B2Test apparatus and test method

Publication Date: 2015.12.15 ADVANTEST CORP

AI summary

Provided is a test apparatus that tests a device under test, comprising a plurality of comparators that each receive a signal under measurement output by the device under test, have a common reference level set therein, and compare a signal level of the signal under measurement to the reference level; and a signal processing section that generates a single result signal based on the plurality of comparison results output by the comparators. Also provided is a test method using the test apparatus.