On-Chip Time-Domain Reflectometry for Non-Invasive Defect Detection

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Solution Overview

Problem

Existing methods for detecting defective parts in electronic circuits are cumbersome and disruptive, requiring disassembly and dedicated hardware for time-domain reflectometry, which is inefficient, especially in large-scale systems like data centers.

Innovation Solution

The integration of time-domain reflectometry (TDR) circuits directly into electronic systems, allowing for non-invasive defect detection using shared hardware and methods that determine defect location and characteristics without disrupting system operations, employing both non-digitizing and digitizing techniques to identify defects such as open or short circuits and impedance deviations.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If dedicated TDR hardware is used for defect detection, then measurement precision is improved, but device complexity increases

Engineering Contradiction:
Improvedefect detection precisionVSAvoidhardware complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent combines TDR measurement functionality with existing communication transceivers by sharing the same transmit path, receive path, and signal processing resources. The TDR measurement is performed by injecting test signals through the existing transmit path and analyzing reflections through the receive path, eliminating the need for separate dedicated TDR hardware while maintaining measurement precision.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The transceiver is designed to perform multiple functions: normal data communication and TDR-based defect detection. The same hardware components (transmit path, receive path, signal processor) are utilized for both communication operations and TDR measurements, allowing a single device to serve dual purposes and reducing overall system complexity.

Inventive Principle:
Principle #6Universality (Multi-functionality)

2Measurement precision

If dedicated TDR hardware is used for defect detection, then measurement precision is improved, but manufacturing cost increases

Engineering Contradiction:
Improvedefect detection precisionVSAvoidmanufacturing cost
Core Design Contradiction:
Measurement precisionVSEase of manufacture

Solution Approach 1:

The patent merges TDR measurement functionality with existing communication transceivers, eliminating the need to manufacture separate dedicated TDR hardware. By sharing transmit paths, receive paths, and signal processing resources, the manufacturing process is simplified and costs are reduced while maintaining the precision of defect detection.

Inventive Principle:
Principle #5Merging (Combining)

3Difficulty of detecting and measuring

If traditional defect detection methods are used, then defect detection capability is achieved, but productivity decreases due to system disruption

Engineering Contradiction:
Improvedefect detection capabilityVSAvoidsystem operational efficiency
Core Design Contradiction:
Difficulty of detecting and measuringVSProductivity

Solution Approach 1:

The system performs TDR measurements during normal operation without requiring preliminary disassembly or shutdown. The defect detection is integrated into the operational workflow, allowing measurements to be taken at any time without disrupting system productivity.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The TDR measurement process is designed to operate continuously alongside normal communication functions. The transceiver can perform defect detection while maintaining data transmission, ensuring that useful actions (both communication and measurement) continue uninterrupted and productivity is maintained.

Inventive Principle:
Principle #20Continuity of useful action

4Measurement precision

If multiple selectable clock signals with different delays are used, then measurement precision is improved, but device complexity increases

Engineering Contradiction:
Improvedefect location precisionVSAvoidclock signal management complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The system dynamically selects from multiple clock signals with different delays based on the measurement requirements. The clock selection is adapted to the specific defect location being measured, allowing precise timing adjustment without requiring all clock signals to be active simultaneously, thus managing complexity while maintaining precision.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The system changes the timing parameter by selecting different clock signals with varying delays. This allows precise adjustment of the measurement timing to match the round-trip propagation time for defects at different locations, improving measurement precision while using a manageable set of discrete clock options rather than continuous timing control.

Inventive Principle:
Principle #35Parameter changes

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

Enables efficient and non-disruptive detection of defects in electronic systems, reducing design and fabrication costs and improving the ability to identify and characterize defects within complex systems, thereby enhancing system reliability and reducing maintenance downtime.

Implementation Method 1

receiving a second signal transition arising in response to a reflection of the first signal transition from the defect

Methodology Applied
Scientific EffectReflection: Reflection

Data Source

PatentEP3796010B1System and methods for on-chip time-domain reflectometry
Publication Date: 2023.10.04 MEDIATEK SINGAPORE PTE LTD
  • EP3796010B1 patent drawingFigure 1
  • EP3796010B1 patent drawingFigure 2A~2B
  • EP3796010B1 patent drawingFigure 2C

AI summary

Systems and methods for detecting the presence and/or location of defects (e.g., incomplete solders, broken cables, misconnections, defective sockets, opens, shorts, etc.) along electrical lines are described. The systems and methods described herein may use time-domain reflectometry (TDR), a measurement technique used to determine the characteristics of electrical lines by observing reflected waveforms. TDR may be performed in some embodiments by determining the times when a first event and a second event occur, and by determining the space traveled by a probe signal based on these times. The first event may occur when a first signal transition crosses a first threshold and the second event may occur when a second signal transition crosses a second threshold, where the second signal transition may arise in response to the first signal transition reflecting against a defect along the electrical line.