Test Apparatus Dynamic Comparator Switching for Mixed-Signal Measurement

Solution Overview

Problem

Conventional test apparatuses struggle to effectively measure signals that dynamically switch between high-speed and low-speed modes, as required by standards like MIPI, due to limitations in comparator speed and signal handling capabilities.

Innovation Solution

A test apparatus equipped with both low-speed and high-speed comparators, along with a switching section that dynamically selects which comparator to use based on the signal output from the device under test, allowing for accurate measurement of signals in both modes by isolating the high-speed comparator when in low-speed mode and utilizing it for high-speed signals.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Speed

If a single high-speed comparator is used to measure high-speed signals, then measurement speed is improved, but the apparatus cannot accurately measure low-speed signals due to excessive speed causing signal distortion or loss

Engineering Contradiction:

Improvemeasurement speedVSAvoidlow-speed signal measurement accuracy

Core Design Contradiction:

SpeedVSMeasurement precision

Solution Approach 1:

The patent divides the measurement function into two separate comparators: a high-speed comparator for measuring high-speed signals and a low-speed comparator for measuring low-speed signals. Each comparator is optimized for its specific speed range, preventing signal distortion while maintaining measurement accuracy for both signal types.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent implements a dynamic switching mechanism that automatically selects which comparator to use based on the signal speed being measured. The switching section responds to signal characteristics in real-time, routing appropriate signals to the suitable comparator, thereby adapting the measurement system to varying signal conditions.

Inventive Principle:

Principle #15Dynamics

2Measurement precision

If a single low-speed comparator is used to measure low-speed signals, then measurement accuracy for low-speed signals is improved, but the apparatus cannot measure high-speed signals due to insufficient speed causing signal distortion or loss

Engineering Contradiction:

Improvelow-speed signal measurement accuracyVSAvoidhigh-speed signal measurement capability

Core Design Contradiction:

Measurement precisionVSSpeed

Solution Approach 1:

The patent divides the measurement function into two separate comparators: a high-speed comparator for measuring high-speed signals and a low-speed comparator for measuring low-speed signals. Each comparator is optimized for its specific speed range, preventing signal distortion while maintaining measurement accuracy for both signal types.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent implements a dynamic switching mechanism that automatically selects which comparator to use based on the signal speed being measured. The switching section responds to signal characteristics in real-time, routing appropriate signals to the suitable comparator, thereby adapting the measurement system to varying signal conditions.

Inventive Principle:

Principle #15Dynamics

3Adaptability or versatility

If dual comparators are used to cover both high-speed and low-speed modes, then adaptability is improved, but device complexity increases due to additional components and switching mechanisms

Engineering Contradiction:

Improvecompatibility with multiple signal modesVSAvoidnumber of comparators and switching components

Core Design Contradiction:

Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent creates a universal measurement apparatus that can handle both high-speed and low-speed signals through a multi-functional design. The switching section acts as a universal interface that routes different signal types to appropriate comparators, allowing a single apparatus to serve multiple measurement functions without requiring separate dedicated systems.

Inventive Principle:

Principle #6Universality (Multi-functionality)

Solution Approach 2:

The switching section serves as an intermediary component that manages the complexity of having dual comparators. It automatically determines signal characteristics and routes signals to the appropriate comparator, shielding the user from the underlying complexity while enabling versatile measurement capabilities.

Inventive Principle:

Principle #24Intermediary (Mediator)

Data Source

PatentUS9157934B2Test apparatus

Publication Date: 2015.10.13 ADVANTEST CORP

AI summary

A test apparatus for testing a device under test, includes a low-speed comparator, a high-speed comparator that is operable faster than the low-speed comparator, and a switching section that switches, according to a signal output from the device under test, which one of the low-speed comparator and the high-speed comparator is used to measure a signal under measurement output from the device under test. The test apparatus may further include a termination resistance that is arranged in parallel with the high-speed comparator.