Protected Isolation Cells for Power Island Boundary Transient Protection

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Solution Overview

Problem

Portable electronic systems face limitations in battery life due to low power efficiency, and existing power island technologies struggle with overvoltage and undervoltage protection at internal nodes of integrated circuits, leading to transient issues and vulnerability to electromagnetic interference.

Innovation Solution

The integration of protected-isolation cells at power island boundaries, which clamp voltage excursions and isolate digital signals, providing overvoltage and undervoltage protection, thereby enhancing robustness and reducing transient vulnerabilities.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Use of energy by moving object

If power islands technology is used to reduce power consumption, then energy efficiency is improved, but the circuit becomes vulnerable to overvoltage and undervoltage transients at internal nodes

Engineering Contradiction:

Improvepower consumptionVSAvoidvulnerability to transients

Core Design Contradiction:

Use of energy by moving objectVSReliability

Solution Approach 1:

The integrated circuit is divided into multiple independent power islands that can be powered on or off separately. Each power island is isolated from others using isolation cells at their boundaries, allowing selective power management to reduce overall power consumption while containing transient effects within individual islands.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Protected isolation cells are inserted at the boundaries between power islands to act as intermediaries. These isolation cells include overvoltage protection circuitry that mediates between different power domains, blocking transient propagation while allowing controlled signal passage when power islands are active.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Reliability

If standard isolation cells are used at power island boundaries, then signal isolation is achieved, but overvoltage and undervoltage protection is insufficient

Engineering Contradiction:

Improvesignal isolationVSAvoidovervoltage and undervoltage damage

Core Design Contradiction:

ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent combines signal isolation functionality with overvoltage/undervoltage protection functionality into a single integrated protected isolation cell. This merged structure performs both isolation and protection functions simultaneously, eliminating the need for separate protection circuits and reducing overall complexity.

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

Overvoltage protection circuitry is pre-configured within the isolation cells to cushion against voltage transients before they can damage sensitive circuitry. The protection mechanism is in place beforehand to clamp or redirect excessive voltages, preventing harm to power island internal nodes.

Inventive Principle:

Principle #11Beforehand cushioning (Prior cushioning)

Data Source

PatentUS8072719B2Systems, circuits, chips and methods with protection at power island boundaries

Publication Date: 2011.12.06 SANDISK TECHNOLOGIES LLC

AI summary

Integrated circuits where the standard isolation cell, at power island boundaries, also includes a protection device, which clamps transient voltages.