ESD Protection Circuit With Small RC Timing and Noise Immunity

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Solution Overview

Problem

Conventional electrostatic discharge protection circuits require large design space and are sensitive to noise, with existing solutions often having large RC time constants and inadequate protection against electrostatic damage in advanced semiconductor devices.

Innovation Solution

An electrostatic discharge protection circuit comprising a pulse detection unit, a delay unit, a control unit, and a discharge unit, which achieves effective protection with a small RC time constant, reduces noise influence, and supports two electrostatic discharge modes, thereby enhancing protection capability while minimizing design space.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a large RC time constant is used in the electrostatic discharge protection circuit, then the electrostatic protection capability is improved, but the circuit area increases

Engineering Contradiction:
Improveelectrostatic protection capabilityVSAvoidcircuit area
Core Design Contradiction:
ReliabilityVSArea of stationary object

Solution Approach 1:

The patent changes the RC time constant parameter to a small value, which is contrary to conventional designs. This is achieved by using a discharge transistor with optimized dimensions (width and length) to create a low-resistance discharge path, allowing fast discharge with small RC time constant while maintaining effective electrostatic protection in advanced semiconductor processes

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent employs a dynamically controlled discharge transistor that is activated only when electrostatic discharge is detected. The discharge transistor is turned on quickly during ESD events and turned off during normal operation, providing adaptive protection that reduces the effective RC time constant when needed while minimizing area overhead

Inventive Principle:
Principle #15Dynamics

2Reliability

If a large RC time constant is used in the electrostatic discharge protection circuit, then the electrostatic protection capability is improved, but the design space occupied increases

Engineering Contradiction:
Improveelectrostatic protection capabilityVSAvoiddesign space
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent uses a small RC time constant achieved through optimized transistor dimensions and configuration. The discharge transistor is designed with specific width-to-length ratios to provide low resistance during discharge while occupying minimal design space in advanced semiconductor manufacturing processes

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The protection circuit is designed to handle multiple discharge modes (positive and negative voltage discharge) using the same basic circuit topology, reducing the overall design space requirements while maintaining comprehensive electrostatic protection capability

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

3Reliability

If conventional electrostatic protection circuits are used, then electrostatic discharge protection is provided, but the circuit is sensitive to noise

Engineering Contradiction:
Improveelectrostatic discharge protectionVSAvoidnoise sensitivity
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent incorporates a detection mechanism that monitors for ESD conditions before full discharge activation occurs. The circuit detects voltage transitions and activates the discharge transistor only when genuine ESD events are detected, preventing premature activation by noise while maintaining fast response to actual discharge events

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The discharge transistor is dynamically controlled with optimized switching characteristics that enable fast activation during ESD events while maintaining high impedance during normal operation. The circuit includes detection logic that distinguishes between noise and genuine ESD events, reducing noise sensitivity while maintaining protection capability

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

The proposed circuit provides robust electrostatic protection with a small design footprint, improved noise immunity, and enhanced protection capabilities, effectively addressing the limitations of existing solutions.

Implementation Method 1

a pulse detection unit configured to detect an electrostatic pulse signal

Methodology Applied
Scientific EffectElectrostatic induction: Electrostatic Induction

Implementation Method 2

a discharge unit configured to dissipate the electrostatic pulse signal

Methodology Applied
Scientific EffectElectrical conduction: Conduction (electrical)

Data Source

PatentEP3975248B1Electrostatic discharge protection circuit
Publication Date: 2023.12.20 CHANGXIN MEMORY TECH INC
  • EP3975248B1 patent drawingFigure 1
  • EP3975248B1 patent drawingFigure 2

AI summary

The present application relates to an electrostatic discharge protection circuit, comprising a pulse detection unit, a delay unit, a control unit, and a discharge unit, wherein the pulse detection unit is used for detecting an electrostatic pulse signal, the delay unit is used for delaying or enhancing the drive capability of a pulse detection signal outputted by the pulse detection unit, the control unit is used for generating a control signal according to a first delay signal and a second delay signal outputted by the delay unit, and the discharge unit is used for opening or closing an electrostatic charge discharge path according to a control signal outputted by the control unit.