Voltage Detector With Programmable Reference Voltage Generator

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Solution Overview

Problem

Conventional voltage detectors using reference voltage generator circuits have a fixed reference voltage, limiting their ability to set the threshold voltage at any desired level.

Innovation Solution

A voltage detector with a reference voltage generator comprising a first write MOS transistor, a second write MOS transistor, a first output MOS transistor, and a second output MOS transistor, where the first write MOS transistor and second write MOS transistor include tunnel oxide films for non-volatile storage, allowing for adjustable reference voltage generation through control of electric charges on floating gates, enabling the detection of input voltages relative to a programmable threshold.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If a conventional reference voltage generator circuit is used, then the circuit structure is simple, but the threshold voltage cannot be adjusted to any desired level

Engineering Contradiction:
Improvethreshold voltage adjustabilityVSAvoidcircuit structure complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent applies dynamics by making the reference voltage adjustable rather than fixed. The circuit transitions from a static configuration to a dynamic one where the threshold voltage can be programmed to any desired level by controlling the amount of electric charge stored in the floating gates of the MOS transistors, enabling continuous adaptation to different detection requirements

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent changes the parameter of reference voltage from a fixed value to a programmable value. By varying the electric charge stored in the floating gates through write operations, the threshold voltage parameter can be adjusted to any desired level, resolving the contradiction between adjustability and circuit complexity

Inventive Principle:
Principle #35Parameter changes

2Adaptability or versatility

If electric charges are controlled in floating gates through tunnel oxide film, then the reference voltage can be dynamically adjusted, but the manufacturing process becomes more complex

Engineering Contradiction:
Improvereference voltage programmabilityVSAvoidtunnel oxide film integration
Core Design Contradiction:
Adaptability or versatilityVSEase of manufacture

Solution Approach 1:

The patent applies preliminary action by pre-programming the desired threshold voltage into the floating gates during the manufacturing or initialization phase. The tunnel oxide film structure is prepared in advance to enable charge storage, and the reference voltage is set before the device enters normal operation, simplifying the overall manufacturing process despite the advanced functionality

Inventive Principle:
Principle #10Preliminary action

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 the voltage detector to set and adjust the reference voltage dynamically, allowing for flexible operation and accurate detection of input voltages relative to a variable threshold, enhancing system performance in energy harvesting applications.

Implementation Method 1

a first write MOS transistor including a control gate and a floating gate, a second write MOS transistor connected in series with the first write MOS transistor, where the second write MOS transistor includes a control gate and a floating gate, a first output MOS transistor including a control gate and a floating gate that are electrically connected to the control gate and the floating gate of the first write MOS transistor, and a second output MOS transistor connected in series with the first output MOS transistor, where the second output MOS transistor includes a control gate and a floating gate that are electrically connected to the control gate and the floating gate of the second write MOS transistor. The first write MOS transistor and the second write MOS transistor are non-volatile storage elements each including a tunnel oxide film that allows electric charges to tunnel therethrough to be injected into the floating gate

Methodology Applied
Scientific EffectTunneling:

Data Source

PatentEP3070846B1Voltage detector and method for setting baseline voltage
Publication Date: 2020.04.01 ASAHI KASEI MICRODEVICES CORP
  • EP3070846B1 patent drawingFigure 1
  • EP3070846B1 patent drawingFigure 2
  • EP3070846B1 patent drawingFigure 3

AI summary

A voltage detector for detecting whether an input voltage is no lower than a predetermined threshold voltage, includes a reference voltage generator configured to generate a reference voltage, and a comparator configured to receive the input voltage and the reference voltage and to detect whether the input voltage is no lower than the threshold voltage that is determined by the reference voltage. Here, the reference voltage generator includes a first write MOS transistor, a second write MOS transistor, a first output MOS transistor and a second output MOS transistor each including a control gate and a floating gate.