Distributed Latch-Up Suppression Switches for Transient Overstress

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Solution Overview

Problem

Electronic systems are vulnerable to transient electrical overstress events, which can cause latch-up in integrated circuits (ICs), leading to damage and design failures, especially in mission-critical applications, due to high power dissipation and overvoltage conditions.

Innovation Solution

The integration of distributed latch-up suppression switches and transient electrical overstress detection circuits in ICs, which activate to clamp power rails and inhibit latch-up in mixed-signal circuits, using thyristors and bipolar transistors for rapid and controlled switching to mitigate latch-up risks.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If distributed latch-up suppression switches are integrated near mixed-signal circuits, then latch-up protection effectiveness is improved, but device complexity increases

Engineering Contradiction:

Improvelatch-up protection effectivenessVSAvoiddevice complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The latch-up suppression function is segmented into multiple distributed switches placed at different locations within the IC, each protecting specific mixed-signal circuits. This segmentation allows localized protection without requiring a single complex centralized protection mechanism, thereby improving protection effectiveness while managing device complexity through modular distribution.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Detection circuits act as intermediaries between the power rails and the latch-up suppression switches. These intermediaries detect transient electrical overstress conditions and trigger the suppression switches only when needed, providing intelligent control that improves protection effectiveness while avoiding unnecessary activation that would increase effective device complexity.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Reliability

If latch-up suppression switches are activated during transient electrical overstress, then protection against latch-up is improved, but power dissipation increases

Engineering Contradiction:

Improvelatch-up protectionVSAvoidpower dissipation

Core Design Contradiction:

ReliabilityVSLoss of energy

Solution Approach 1:

The latch-up suppression switches are activated periodically or transiently only during detected electrical overstress events rather than continuously. This periodic activation provides necessary protection during critical moments while minimizing power dissipation during normal operation, resolving the contradiction between protection effectiveness and energy loss.

Inventive Principle:

Principle #19Periodic action

Solution Approach 2:

The detection circuits automatically detect electrical overstress conditions and trigger the suppression switches without external intervention. This self-service mechanism ensures protection is activated precisely when needed based on actual conditions, avoiding unnecessary activation that would increase power dissipation while maintaining reliable protection.

Inventive Principle:

Principle #25Self-service

3Measurement precision

If detection circuits are added to detect transient electrical overstress, then detection precision is improved, but device complexity increases

Engineering Contradiction:

Improvetransient overstress detection precisionVSAvoiddevice complexity

Core Design Contradiction:

Measurement precisionVSDevice complexity

Solution Approach 1:

Detection circuits are placed locally near the power rails and mixed-signal circuits they protect, enabling precise detection of transient electrical overstress conditions at the source. This local placement improves detection precision by capturing conditions where they originate while minimizing the complexity impact through distributed, simple detection logic rather than a complex centralized detection system.

Inventive Principle:

Principle #3Local quality

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 solution effectively prevents latch-up in CMOS core mixed-signal circuits by clamping power rails during transient electrical overstress events, reducing the risk of damage and ensuring reliable operation even before other ESD protection devices activate, with a compact layout suitable for integration near sensitive circuitry.

Implementation Method 1

the latch-up suppression switches temporarily clamp the power rails to one another in response to activation of the transient overstress detection signal to inhibit latch-up of the mixed-signal circuits

Methodology Applied

Scientific EffectClamping:

Data Source

PatentUS10404059B2Distributed switches to suppress transient electrical overstress-induced latch-up

Publication Date: 2019.09.03 ANALOG DEVICES INC

AI summary

Distributed switches to suppress transient electrical overstress-induced latch-up are provided. In certain configurations, an integrated circuit (IC) or semiconductor chip includes a transient electrical overstress detection circuit that activates a transient overstress detection signal in response to detecting a transient electrical overstress event between a pair of power rails. The IC further includes mixed-signal circuits and latch-up suppression switches distributed across the IC, and the latch-up suppression switches temporarily clamp the power rails to one another in response to activation of the transient overstress detection signal to inhibit latch-up of the mixed-signal circuits.