Pre-charge and Equalization Devices Using Lower Supply Voltage

Solution Overview

Problem

Existing pre-charge and equalization devices in DRAM consume high power due to the use of high voltage VPP, leading to increased size and reduced speed due to thick gate oxide requirements, which is inefficient and slows down the devices.

Innovation Solution

A lower supply voltage VPP2 is used to generate a high voltage for pre-charge and equalization, allowing the use of regular gate oxide thickness devices, reducing power consumption and maintaining an acceptable stress level, while ensuring sufficient voltage for bit line pre-charge and equalization.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If high voltage VPP is used to power pre-charge and equalization devices, then sufficient voltage for bit line pre-charge and equalization is maintained, but power consumption increases

Engineering Contradiction:

Improvevoltage sufficiency for bit line pre-charge and equalizationVSAvoidpower consumption of pre-charge and equalization devices

Core Design Contradiction:

ReliabilityVSUse of energy by moving object

Solution Approach 1:

The patent segments the voltage supply system by introducing a dedicated lower voltage source VPP2 specifically for pre-charge and equalization devices, separate from the high voltage VPP1 used for word line activation. This segmentation allows each component to receive appropriate voltage levels, reducing overall power consumption while maintaining operational reliability.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent changes the voltage parameter from high VPP1 to a lower optimized VPP2 for pre-charge and equalization devices. This parameter change reduces power consumption (P=V²/R) while still providing sufficient voltage headroom for proper bit line pre-charge and equalization operation, as verified by the acceptable stress levels on gate oxide.

Inventive Principle:

Principle #35Parameter changes

2Reliability

If thick gate oxide is used in pre-charge and equalization devices to withstand high voltage VPP, then device reliability improves, but device size increases and speed decreases

Engineering Contradiction:

Improvevoltage withstanding capabilityVSAvoiddevice operation speed

Core Design Contradiction:

ReliabilityVSSpeed

Solution Approach 1:

The patent changes the voltage parameter from high VPP1 to a lower optimized VPP2 for pre-charge and equalization devices. This parameter change reduces power consumption (P=V²/R) while still providing sufficient voltage headroom for proper bit line pre-charge and equalization operation, as verified by the acceptable stress levels on gate oxide.

Inventive Principle:

Principle #35Parameter changes

3Reliability

If thick gate oxide is used in pre-charge and equalization devices to withstand high voltage VPP, then device reliability improves, but device area increases

Engineering Contradiction:

Improvevoltage withstanding capabilityVSAvoiddevice die area

Core Design Contradiction:

ReliabilityVSArea of stationary object

Solution Approach 1:

The patent changes the voltage parameter from high VPP1 to a lower optimized VPP2 for pre-charge and equalization devices. This parameter change reduces power consumption (P=V²/R) while still providing sufficient voltage headroom for proper bit line pre-charge and equalization operation, as verified by the acceptable stress levels on gate oxide.

Inventive Principle:

Principle #35Parameter changes

Data Source

PatentUS8681576B2Pre-charge and equalization devices

Publication Date: 2014.03.25 TAIWAN SEMICONDUCTOR MANUFACTURING CO LTD

AI summary

A circuit comprises a set of pre-charge and equalization devices, a control signal line, and a word line. The set of pre-charge and equalization devices is configured to pre-charge and equalize a pair of data lines. The control signal line is configured to control the pre-charge and equalization devices. The word line is configured to electrically couple a memory cell to a data line of the pair of data lines. A first voltage value provided to the control signal line is from a first voltage source different from a second voltage source that generates a second voltage value for the word line.