Reference Potential Generation Circuit Without External Ground

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Solution Overview

Problem

Existing reference potential generation circuits require an external ground potential for operation, necessitating an external terminal for supply, which limits their application in electronic devices.

Innovation Solution

A reference potential generation circuit comprising a low-pass filter and a linear regulator, where a start pulse signal is used to generate a reference potential without external ground potential, utilizing a low-pass filter with a resistor and capacitor, and a linear regulator with p-channel and n-channel transistors to produce a potential equal to ground potential.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If an external ground potential is supplied to generate a reference voltage, then the reference voltage can be generated, but an external terminal for supplying ground potential is necessary

Engineering Contradiction:

Improvereference voltage generationVSAvoidexternal terminal requirement

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The circuit generates its own reference potential using internal power supply potentials (first power supply potential and second power supply potential with opposite polarity) without requiring external ground potential supply. The operational amplifier and resistor network create a virtual ground reference point internally, making the circuit self-sufficient and eliminating external grounding terminals.

Inventive Principle:

Principle #25Self-service

Solution Approach 2:

Instead of using external ground potential as the reference basis, the invention inverts the approach by using two power supply potentials of opposite polarity and generating the reference potential internally through circuit elements. This inversion eliminates the need for external ground connection while achieving the same reference function.

Inventive Principle:

Principle #13The other way round (Inversion)

2Ease of operation

If a ground potential is supplied from outside, then the electronic device can operate, but the number of external terminals increases

Engineering Contradiction:

Improvedevice operationVSAvoidnumber of external terminals

Core Design Contradiction:

Ease of operationVSDevice complexity

Solution Approach 1:

The electronic device generates its own reference potential using internal power supply connections, eliminating the need for external ground terminals. The circuit uses the available power supply potentials to create the necessary reference point, reducing external terminal requirements while maintaining full operational capability.

Inventive Principle:

Principle #25Self-service

Solution Approach 2:

The power supply terminals serve dual functions: providing power to the circuit and simultaneously establishing the reference potential. This multi-functionality eliminates the need for separate ground terminals, reducing the total number of external connections required while maintaining device operation.

Inventive Principle:

Principle #6Universality (Multi-functionality)

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 electronic devices to operate without an external ground potential supply, providing a stable reference potential for normal operation, reducing the need for external grounding terminals.

Implementation Method 1

a low-pass filter including a first terminal, a second terminal, and a third terminal

Methodology Applied

Scientific EffectLow-pass filtering: Filter (electronic)

Implementation Method 2

a linear regulator including a first terminal, a second terminal, a third terminal, and a fourth terminal

Methodology Applied

Scientific EffectLinear regulation:

Data Source

PatentUS9939835B2Reference potential generation circuit

Publication Date: 2018.04.10 SEMICON ENERGY LAB CO LTD

AI summary

A reference potential generation circuit is provided. The reference potential generation circuit includes first to third input terminals, first and second output terminals, a low-pass filter including first to third terminals, and a linear regulator including first to fourth terminals. In the reference potential generation circuit, the first terminal of the low-pass filter is electrically connected to the second input terminal. The second terminal of the low-pass filter is electrically connected to the first input terminal or the third input terminal. The third terminal of the low-pass filter is electrically connected to the first terminal of the linear regulator. The second terminal of the linear regulator is electrically connected to the first input terminal and the first output terminal. The third terminal of the linear regulator is electrically connected to the second output terminal. The fourth terminal of the linear regulator is electrically connected to the third input terminal.