Level-Shift Signal Line Clamping for Low-Power IC Transmission

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Solution Overview

Problem

In semiconductor integrated circuits, the current consumption due to signal transitions in transmission lines is high due to repeated charge/discharge cycles between high and low levels, and existing solutions fail to effectively manage voltage fluctuations caused by aggressor circuits, which can lead to breakdown voltage issues.

Innovation Solution

A semiconductor integrated circuit design incorporating a level shift transistor that reduces signal amplitude by outputting signals with a voltage lower than the power supply voltage by its threshold voltage, and a protection circuit that allows current flow when the transmission line voltage exceeds a set voltage, preventing voltage fluctuations and breakdowns.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If signal lines repeatedly transition between high and low levels for data transmission, then data communication between circuit blocks is achieved, but current consumption increases due to charge/discharge of electric charges

Engineering Contradiction:

Improvedata transmission capabilityVSAvoidcurrent consumption

Core Design Contradiction:

ProductivityVSUse of energy by moving object

Solution Approach 1:

The patent changes the voltage parameter of the signal line by connecting a protection circuit that clamps the voltage to a safe level. When voltage exceeds the breakdown voltage, the protection circuit activates to limit the voltage, thereby changing the electrical parameter to prevent excessive current consumption and damage to circuit elements.

Inventive Principle:

Principle #35Parameter changes

2Reliability

If signal amplitude is increased for reliable signal transmission, then signal integrity is improved, but voltage fluctuations may exceed the breakdown limits of connected elements

Engineering Contradiction:

Improvesignal transmission reliabilityVSAvoidvoltage-induced breakdown risk

Core Design Contradiction:

ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The protection circuit is pre-connected to the signal line to provide beforehand cushioning against voltage spikes. The circuit is designed to activate when voltage exceeds a predetermined level, cushioning the signal line and connected elements from harmful voltage fluctuations before they can cause breakdown.

Inventive Principle:

Principle #11Beforehand cushioning (Prior cushioning)

Solution Approach 2:

The protection circuit acts as an intermediary between the signal line and connected elements. It mediates the voltage level by clamping excessive voltage, thereby protecting downstream elements from harmful voltage while allowing normal signal transmission to proceed.

Inventive Principle:

Principle #24Intermediary (Mediator)

3Reliability

If protection circuits are added to prevent voltage breakdown, then element safety is improved, but chip area increases

Engineering Contradiction:

Improveelement protection capabilityVSAvoidchip area

Core Design Contradiction:

ReliabilityVSArea of stationary object

Solution Approach 1:

The protection circuit uses simple, inexpensive components such as diodes or transistors that can be easily integrated into the chip. These components are designed to be replaced or reset if damaged, providing a cost-effective and area-efficient solution for protecting expensive circuit elements.

Inventive Principle:

Principle #27Cheap short-living objects (Disposable)

Solution Approach 2:

The protection circuit changes the electrical parameter (voltage) of the signal line by clamping it to a safe level. This parameter change approach allows for a simple circuit implementation that requires minimal area while providing effective protection against voltage-induced breakdown.

Inventive Principle:

Principle #35Parameter changes

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

This design reduces current consumption and prevents voltage breakdowns by reducing signal amplitude and controlling voltage fluctuations, thereby enhancing the reliability and efficiency of signal transmission in semiconductor integrated circuits.

Implementation Method 1

outputs, to the transmission line, a signal having an amplitude lower than the first voltage by a threshold voltage of the level shift transistor

Methodology Applied

Scientific EffectThreshold voltage effect:

Implementation Method 2

The third circuit allows a current to flow from the transmission line when a voltage of the transmission line exceeds a set voltage

Methodology Applied

Scientific EffectVoltage clamping:

Data Source

PatentUS20230292503A1Semiconductor integrated circuit

Publication Date: 2023.09.14 KIOXIA CORP

AI summary

According to one embodiment, a semiconductor integrated circuit includes a first circuit that includes a level shift transistor, a transmission line through which the signal output from the first circuit propagates, a second circuit that is connected the transmission line to receive the signal propagating through the transmission line, and a third circuit that is connected to the transmission line. The first circuit is connected to a power supply line to which a first voltage is supplied, and outputs, to the transmission line, a signal having an amplitude lower than the first voltage by a threshold voltage of the level shift transistor. The third circuit allows a current to flow from the transmission line when a voltage of the transmission line exceeds a set voltage.