Memory Differential Amplifier Offset Compensation During Sensing

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Solution Overview

Problem

Existing memory technologies face inefficiencies in sensing data states due to offset issues in differential amplifiers, which require lengthy pre-charge times to compensate for digit line electrical characteristics, thereby prolonging the time needed to sense memory cell data states.

Innovation Solution

Implementing a differential amplifier with a stored offset to cancel the offset caused by digit line electrical characteristics, reducing the need for pre-charge time by reconnecting amplifier inputs to apply the target voltage without the offset during sensing operations.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If pre-charge is used to compensate for digit line electrical characteristics, then measurement precision is improved, but loss of time increases

Engineering Contradiction:
Improvesensing accuracyVSAvoidpre-charge time
Core Design Contradiction:
Measurement precisionVSLoss of time

Solution Approach 1:

The patent applies preliminary action by pre-charging the capacitor with the offset value before the sensing operation. This prepares the differential amplifier in advance with the correct reference voltage level, eliminating the need for time-consuming pre-charge cycles during actual sensing operations. The offset is captured during a calibration phase and stored for subsequent use.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent uses copying by creating a replica of the offset voltage and storing it in a capacitor. This copied offset value is then used to compensate for digit line electrical characteristics during sensing operations, replacing the need for real-time pre-charge compensation while maintaining measurement accuracy.

Inventive Principle:
Principle #26Copying

2Reliability

If pre-charge is performed to compensate for offset, then reliability is improved, but productivity decreases

Engineering Contradiction:
Improvesensing reliabilityVSAvoidsensing speed
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The differential amplifier is pre-configured with the offset compensation value before sensing operations begin. This preliminary setup ensures reliable sensing throughout the operational phase without repeatedly interrupting to perform pre-charge cycles, thereby maintaining both reliability and high productivity.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

By storing the offset compensation value in a capacitor, the patent enables continuous sensing operations without interruption for pre-charge cycles. The useful action of sensing continues uninterrupted, improving productivity while maintaining reliability through the stored offset compensation.

Inventive Principle:
Principle #20Continuity of useful action

3Measurement precision

If offset compensation is implemented, then measurement precision is improved, but device complexity increases

Engineering Contradiction:
Improvedata state sensing accuracyVSAvoidamplifier circuit complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent introduces a capacitor as an intermediary element to store the offset compensation value. This simple passive component acts as a mediator between the offset generation circuitry and the differential amplifier, enabling precise compensation without adding complex active circuitry or control logic.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent changes the voltage parameter of the capacitor to match the offset value, thereby compensating for digit line electrical characteristics. By adjusting this single parameter (voltage) rather than redesigning the entire amplifier circuit, measurement precision is improved with minimal increase in device complexity.

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 approach decreases the time required to sense memory cell data states, enhancing memory performance by eliminating the need for pre-charge and streamlining the sensing process.

Implementation Method 1

a capacitor coupled to the second input and configured to store an offset of the differential amplifier

Methodology Applied
Scientific EffectCapacitance: Capacitance

Data Source

PatentEP4621778A1Differential amplifier offset in memory
Publication Date: 2025.09.24 MICRON TECHNOLOGY INC
  • EP4621778A1 patent drawingFigure 1A~1B
  • EP4621778A1 patent drawingFigure 2A~2B
  • EP4621778A1 patent drawingFigure 3A

AI summary

The present disclosure includes apparatuses, methods, and systems for differential amplifier offset in memory. An embodiment includes an array of memory cells, a differential amplifier having a first input and a second input, wherein the first input is connectable to a target voltage, and a capacitor coupled to the second input and configured to store an offset of the differential amplifier. The differential amplifier is configured to, during an operation to sense a data state of a memory cell of the array, reconnect the first input and the second input.