ADC Verification Using Quantization Noise for Fault Detection

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Solution Overview

Problem

Existing analog-to-digital converters (ADCs) in power delivery systems often fail to accurately detect faults, leading to unintended operations due to false or inaccurate data, which can result in system malfunctions and safety risks, as current error detection methods are either costly, inaccurate, or take too long to detect failures.

Innovation Solution

The proposed solution involves verifying the quantization noise properties of ADCs using noise-shaping techniques, such as delta-sigma modulators, by monitoring deviations from expected noise characteristics, employing bandpass filters to compare RMS values across frequency bands, and using threshold comparisons to determine ADC health and detect errors.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If traditional error detection methods are used in ADCs, then system cost increases, but detection accuracy does not improve significantly

Engineering Contradiction:
Improvefault detection accuracyVSAvoidsystem cost
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The ADC system performs self-verification by monitoring its own quantization noise characteristics. The verification module analyzes the noise properties of the ADC output without requiring external test equipment or additional sensors, enabling the system to detect its own failures autonomously

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The invention converts the harmful quantization noise, which is normally considered a source of error and distortion, into a useful verification signal. By analyzing the statistical properties and spectral characteristics of this noise, the system can detect ADC failures without requiring separate test signals or additional hardware

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

2Reliability

If traditional error detection methods are used in ADCs, then system reliability decreases, but detection time increases

Engineering Contradiction:
Improvesystem reliabilityVSAvoiddetection time
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

The verification module continuously monitors the quantization noise characteristics of the ADC in real-time during normal operation. This continuous verification ensures that failures are detected immediately when they occur, maintaining high system reliability without introducing detection delays

Inventive Principle:
Principle #20Continuity of useful action

Solution Approach 2:

The system performs preliminary verification of ADC health by continuously analyzing quantization noise properties before critical failures occur. The verification process checks statistical parameters and spectral characteristics proactively, enabling early detection of degradation trends before they lead to complete system failure

Inventive Principle:
Principle #10Preliminary action

3Measurement precision

If quantization noise verification is implemented, then ADC failure detection accuracy improves, but computational complexity increases

Engineering Contradiction:
Improvefailure detection accuracyVSAvoidcomputational complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The verification process is segmented into distinct analytical stages: extracting quantization noise from the ADC output, computing statistical parameters (mean, variance, skewness), performing spectral analysis, and comparing results against reference thresholds. This segmentation allows each computational task to be optimized independently and implemented efficiently in hardware or firmware

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The system implements verification at appropriate levels of detail without unnecessary complexity. Rather than performing exhaustive analysis of all signal characteristics, the verification module focuses on specific quantization noise properties (statistical moments and spectral density) that are most indicative of ADC health, achieving high detection accuracy with computationally efficient algorithms

Inventive Principle:
Principle #16Partial or excessive action

Data Source

PatentUS9985646B1Analog-to-digital converter verification using quantization noise properties
Publication Date: 2018.05.29 SCHWEITZER ENGINEERING LABORATORIES INC
  • US9985646B1 patent drawing
  • US9985646B1 patent drawing
  • US9985646B1 patent drawing

AI summary

Disclosed are systems and methods for identifying and reporting failures of an analog-to-digital converter (ADC). Specifically, the systems and methods described herein evaluate quantization noise properties of ADCs, including delta-sigma ADCs and successive approximation register (SAR) ADCs, to verify functionality and/or identify failures. Quantization noise properties can be evaluated in the frequency domain by, for example, comparing RMS values, magnitudes, frequency spectrums, and the like, in various frequency bands to threshold values and/or to verify an expected noise shape. Quantization noise properties can additionally or alternatively be evaluated in the time domain by, for example, comparing counts of pulse widths, average pulse widths, and/or number of transitions within a sequence of pulses to threshold values and/or to similar identifiable characteristics in other pulse width bands.