Self-timer for Sense Amplifier in Flash Memory

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Existing sense amplifiers in flash memory devices fail to compensate for the inherent capacitance of bit lines, which affects the timing and accuracy of read operations.

Innovation Solution

A timing generator is introduced that receives a pre-charged bit line and a reference cell emulating the selected memory cell, generating a control signal to improve the synchronization of sense amplifier operations, thereby compensating for bit line capacitance.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If a sense amplifier uses a reference cell and current mirrors to determine stored values, then the sensing operation can be performed, but the inherent capacitance of the bit line affects the timing and accuracy of the sense amplifier

Engineering Contradiction:

Improvesensing accuracyVSAvoidbit line capacitance effect

Core Design Contradiction:

Measurement precisionVSObject-affected harmful factors

Solution Approach 1:

The patent creates a copy of the bit line capacitance effect by introducing a dummy memory cell with identical capacitance characteristics. This dummy cell is connected to a dummy bit line that replicates the electrical characteristics of the actual bit line. By measuring the discharge characteristics of this dummy cell, the circuit compensates for the capacitance effect without requiring direct measurement of the actual bit line's capacitance, thus resolving the accuracy issue while maintaining simplicity.

Inventive Principle:

Principle #26Copying

2Device complexity

If the sense amplifier operates without compensation for bit line capacitance, then the circuit design remains simple, but the timing and accuracy of read operations are negatively impacted

Engineering Contradiction:

Improvecircuit design simplicityVSAvoidread operation reliability

Core Design Contradiction:

Device complexityVSReliability

Solution Approach 1:

The patent introduces an intermediary compensation circuit that includes a dummy memory cell and control logic. This intermediary system measures the discharge characteristics of the dummy cell and generates a compensation signal that adjusts the sense amplifier's operation. The intermediary circuit acts as a mediator between the bit line capacitance effect and the sense amplifier, allowing the main sensing function to remain simple while adding compensation only where needed to maintain reliability.

Inventive Principle:

Principle #24Intermediary (Mediator)

Data Source

PatentEP2973570B1Self-timer for sense amplifier in memory device

Publication Date: 2018.05.16 SILICON STORAGE TECHNOLOGY INC

Figure 1
Figure 2
Figure 3

AI summary

A self-timer for a sense amplifier in a memory device is disclosed.