Stepwise Threshold Voltage Circuit for ADC-Free Variation Detection

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Solution Overview

Problem

Existing voltage variation detection circuits rely on A/D converters, resulting in large-scale circuitry and inefficiencies, which is undesirable for compact and efficient voltage monitoring applications.

Innovation Solution

A voltage variation detection circuit that uses threshold voltage generation and comparison with stepwise adjustments, eliminating the need for A/D converters by employing a controller to manage first and second threshold voltages, allowing for detection of voltage variations without A/D conversion.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If an A/D converter is used to detect voltage variations, then voltage detection accuracy is improved, but circuit scale increases

Engineering Contradiction:
Improvevoltage detection accuracyVSAvoidcircuit scale
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The invention extracts only the essential function of voltage threshold comparison from the complete A/D conversion process. By removing the complex digital conversion stages and keeping only the critical threshold detection capability through comparator circuits, the circuit achieves voltage variation detection without the large scale of full A/D converters.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The invention replaces expensive, complex A/D converter components with simpler, more economical comparator circuits. The threshold voltage generation circuit and comparators provide adequate detection capability for voltage variation monitoring at a fraction of the complexity and cost of A/D converters.

Inventive Principle:
Principle #27Cheap short-living objects (Disposable)

2Device complexity

If threshold voltage is adjusted stepwise with controller management, then circuit complexity is reduced, but detection response time may increase

Engineering Contradiction:
Improvecircuit complexityVSAvoiddetection response time
Core Design Contradiction:
Device complexityVSLoss of time

Solution Approach 1:

The invention implements dynamic threshold voltage adjustment where the threshold voltage changes stepwise based on control signals. The threshold voltage generation circuit responds to control inputs by adjusting threshold levels in discrete steps, providing adaptive detection capability while maintaining relatively simple circuit architecture through controlled dynamic behavior.

Inventive Principle:
Principle #15Dynamics

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 detection of voltage variations with reduced circuit complexity, preventing glitches and allowing for overvoltage and low-voltage notifications, while maintaining accurate monitoring without A/D converters.

Implementation Method 1

a first comparator arranged to compare a variation detection-target voltage and the first threshold voltage to each other; a second comparator arranged to compare the variation detection-target voltage and the second threshold voltage to each other

Methodology Applied
Scientific EffectVoltage comparison:

Data Source

PatentEP3333581B1Voltage variation detection circuit, semiconductor integrated circuit, and vehicle
Publication Date: 2020.11.18 ROHM CO LTD
  • EP3333581B1 patent drawingFigure 1~3
  • EP3333581B1 patent drawingFigure 4~5
  • EP3333581B1 patent drawingFigure 6~7

AI summary

The voltage variation detection circuit includes: a threshold voltage generation circuit (1, 2A and 3) arranged to generate a threshold voltage; a comparator (4A) arranged to compare a variation detection-target voltage and the threshold voltage to each other; and a controller (5A) arranged to control the threshold voltage generation circuit based on output of the comparator. Repeated are operations of: decreasing the threshold voltage stepwise; when the variation detection-target voltage has come to the threshold voltage or more, first increasing the threshold voltage by specified steps and then again decreasing the threshold voltage stepwise; and when the variation detection-target voltage has come to the threshold voltage or more, increasing the threshold voltage by specified steps. The controller detects a variation of the variation detection-target voltage based on control results at time points when the variation detection-target voltage comes to the threshold voltage or more.