Partitioned Reference Voltage Distribution for Memory Stability

Solution Overview

Problem

In memory devices with multiple banks, the stability of the biasing reference voltage is disturbed during operations, affecting the reliability of data read and verify operations, especially in multilevel memory cells that require high precision.

Innovation Solution

A global reference voltage is applied to multiple partitions via switches, allowing each partition to be electrically isolated during read and verify operations, using capacitance to supply a stable reference voltage that is not affected by circuit activities in other partitions.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If multiple banks share a same biasing reference voltage source, then device complexity is reduced, but stability of the reference voltage deteriorates due to mutual disturbance between banks

Engineering Contradiction:

Improvereference voltage source configurationVSAvoidbiasing reference voltage stability

Core Design Contradiction:

Device complexityVSStability of the object's composition

Solution Approach 1:

The patent divides the memory device into multiple partitions, each with its own separate biasing reference voltage source. This segmentation isolates the reference voltage sources so that operations in one partition do not disturb the reference voltage in other partitions, thereby maintaining stability while supporting multiple concurrent operations.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent introduces switching circuitry as an intermediary between the reference voltage sources and the sense amplifiers. The switches selectively connect or disconnect partitions from their reference voltage sources based on operational state, allowing the reference voltage to be stabilized during standby while enabling operations when needed.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Ease of manufacture

If multiple banks share a same biasing reference voltage source, then manufacturing cost is reduced, but reliability of data read and verify operations deteriorates

Engineering Contradiction:

Improvereference voltage source implementationVSAvoiddata read and verify operation reliability

Core Design Contradiction:

Ease of manufactureVSReliability

Solution Approach 1:

The patent divides the memory device into multiple partitions, each with its own separate biasing reference voltage source. This segmentation isolates the reference voltage sources so that operations in one partition do not disturb the reference voltage in other partitions, thereby maintaining stability while supporting multiple concurrent operations.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent introduces switching circuitry as an intermediary between the reference voltage sources and the sense amplifiers. The switches selectively connect or disconnect partitions from their reference voltage sources based on operational state, allowing the reference voltage to be stabilized during standby while enabling operations when needed.

Inventive Principle:

Principle #24Intermediary (Mediator)

3Measurement precision

If a sense amplifier uses high precision to distinguish multilevel memory cell contents, then measurement precision is improved, but sensitivity to reference voltage disturbance increases

Engineering Contradiction:

Improvesense amplifier measurement precisionVSAvoidreference voltage disturbance sensitivity

Core Design Contradiction:

Measurement precisionVSObject-affected harmful factors

Solution Approach 1:

The patent divides the memory device into multiple partitions, each with its own separate biasing reference voltage source. This segmentation isolates the reference voltage sources so that operations in one partition do not disturb the reference voltage in other partitions, thereby maintaining stability while supporting multiple concurrent operations.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent introduces switching circuitry as an intermediary between the reference voltage sources and the sense amplifiers. The switches selectively connect or disconnect partitions from their reference voltage sources based on operational state, allowing the reference voltage to be stabilized during standby while enabling operations when needed.

Inventive Principle:

Principle #24Intermediary (Mediator)

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 approach ensures accurate and stable voltage measurements for memory cells by isolating each partition from disturbances in other partitions, maintaining the integrity of data read and verify operations.

Implementation Method 1

A capacitance may be electrically connected to an output of the global reference voltage source. The capacitance may supply a reference voltage to circuit elements of the partition

Methodology Applied

Scientific EffectCapacitance: Capacitance

Data Source

PatentUS7903478B1High impedance reference voltage distribution

Publication Date: 2011.03.08 MICRON TECHNOLOGY INC

AI summary

A sense amplifier may be used to measure voltages and/or currents that represent logic levels stored in memory cells of memory devices. Accuracy and stability of such measurements may be improved by selective switching to isolate sense amplifiers from other portions of a circuit.