Shared Level Shifter for Memory Word-Line Drivers

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Solution Overview

Problem

Integrated circuit memory devices face challenges in efficiently managing different voltage levels across various modules, leading to significant power consumption and device area requirements due to the need for voltage level shifting circuits.

Innovation Solution

A memory device design that incorporates a single level shifter connected to multiple driver modules, utilizing PMOS and NMOS transistors to implement a precharge-discharge technique, allowing for efficient voltage level shifting between modules operating at different voltage levels, thereby reducing the area and power consumption.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If voltage level shifting circuits are used to interface between modules operating at different voltage levels, then correct operation across different voltage levels is achieved, but device area and power consumption increase significantly

Engineering Contradiction:

Improvecorrect operation across different voltage levelsVSAvoiddevice area

Core Design Contradiction:

ReliabilityVSArea of stationary object

Solution Approach 1:

The patent merges multiple level shifting functions into a single shared level shifter that serves multiple driver modules. Instead of having dedicated level shifters for each driver module, the invention uses one level shifter that is time-multiplexed across multiple drivers, thereby reducing the total device area while maintaining correct voltage level interfacing between different voltage domains

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The level shifter is designed with universal functionality to interface with multiple driver modules that operate at different voltage levels. The single level shifter can dynamically serve different drivers based on control signals, making it a multi-functional component that replaces what would traditionally require multiple dedicated level shifters

Inventive Principle:

Principle #6Universality (Multi-functionality)

2Reliability

Engineering Contradiction:

Improvecorrect operation across different voltage levelsVSAvoidpower consumption

Core Design Contradiction:

ReliabilityVSUse of energy by stationary object

Solution Approach 1:

By combining multiple level shifting operations into a single shared level shifter, the total power consumption is reduced compared to having multiple independent level shifters. The shared level shifter performs level shifting for multiple drivers sequentially or in a time-multiplexed manner, thereby distributing and reducing the overall power burden while maintaining correct voltage level interfacing

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The level shifter operates in a periodic or time-multiplexed manner, serving different driver modules at different time intervals rather than continuously operating multiple level shifters simultaneously. This periodic operation reduces instantaneous and average power consumption while ensuring that each driver receives the necessary voltage level translation when needed

Inventive Principle:

Principle #19Periodic action

3Productivity

If multiple driver modules are implemented to drive multiple word-lines, then word-line driving capability is improved, but the area required for level shifting increases

Engineering Contradiction:

Improveword-line driving capabilityVSAvoidarea for level shifting

Core Design Contradiction:

ProductivityVSArea of stationary object

Solution Approach 1:

The patent combines the level shifting functionality for multiple driver modules into a single shared level shifter. This merging approach allows multiple drivers to maintain their word-line driving capability while sharing the same level shifting resource, thereby preventing the total area for level shifting from increasing proportionally with the number of drivers

Inventive Principle:

Principle #5Merging (Combining)

4Area of stationary object

If a single level shifter is shared among multiple driver modules, then area and power consumption are reduced, but the complexity of managing voltage levels increases

Engineering Contradiction:

Improvearea for level shiftingVSAvoidcomplexity of managing voltage levels

Core Design Contradiction:

Area of stationary objectVSDevice complexity

Solution Approach 1:

The system employs feedback mechanisms to manage the shared level shifter, where control logic monitors which driver module requires level shifting services and dynamically allocates the level shifter resources accordingly. This feedback-based control manages the complexity of voltage level coordination while enabling efficient sharing of the level shifting function across multiple drivers

Inventive Principle:

Principle #23Feedback

Data Source

PatentUS7940580B2Voltage shifting word-line driver and method therefor

Publication Date: 2011.05.10 ADVANCED MICRO DEVICES INC

AI summary

A memory device is disclosed that includes a plurality of word-lines, with each word-line connected to at least one bitcell. Each of the plurality of word-lines is connected to a corresponding driver module to drive the word-line in response to a corresponding select signal. Further, each driver module is connected to a level shifter to shift the corresponding select signal so that the driver module provides a level-shifted signal at the first word-line in response to assertion of the first select signal. A single level shifter can be connected to multiple driver modules, thereby reducing the area required to implement level-shifting for multiple word-lines.