Nonvolatile Memory Voltage Overshoot Control

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Solution Overview

Problem

Nonvolatile memory devices face the challenge of preventing or reducing overshoot in internal voltage during word-line recovery operations, which can lead to inefficiencies and potential errors in data storage and retrieval.

Innovation Solution

A method and device configuration where the internal voltage connected to unselected word-lines is consumed by a particular circuit not associated with the word-line recovery operation, allowing the voltage level of unselected word-lines to be recovered to an internal voltage level, thereby preventing or reducing overshoot.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Stability of the object's composition

If the internal voltage is connected to unselected word-lines during word-line recovery operation, then the voltage level can be recovered, but overshoot of internal voltage occurs

Engineering Contradiction:

Improvevoltage level stabilityVSAvoidvoltage overshoot

Core Design Contradiction:

Stability of the object's compositionVSObject-generated harmful factors

Solution Approach 1:

The patent extracts the internal voltage connection from the word-line recovery operation by introducing a separate discharge period where the internal voltage is consumed by a particular circuit unrelated to word-line recovery. This separation eliminates the harmful overshoot effect while maintaining the beneficial voltage recovery function.

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The patent implements periodic action by dividing the recovery process into distinct periods: a sensing period where read pass voltage is applied to unselected word-lines, followed by a discharge period where the internal voltage is consumed by a particular circuit. This periodic separation allows voltage recovery without overshoot.

Inventive Principle:

Principle #19Periodic action

2Object-generated harmful factors

If a particular circuit is activated to consume internal voltage during discharge period, then overshoot is prevented, but device complexity increases

Engineering Contradiction:

Improvevoltage overshoot preventionVSAvoidcircuit complexity

Core Design Contradiction:

Object-generated harmful factorsVSDevice complexity

Solution Approach 1:

The patent applies universality by using a particular circuit that performs multiple functions: it consumes internal voltage during the discharge period to prevent overshoot, while also being unrelated to the word-line recovery operation. This multi-functional approach prevents overshoot without significantly increasing device complexity.

Inventive Principle:

Principle #6Universality (Multi-functionality)

Data Source

PatentUS12190964B2Nonvolatile memory device preventing overshoot of internal voltage and method of operating nonvolatile memory device

Publication Date: 2025.01.07 SAMSUNG ELECTRONICS CO LTD

AI summary

In a method of operating a nonvolatile memory device that includes a memory block including cell strings where each of the cell strings includes a string selection transistor, memory cells and a ground selection transistor which are connected in series and disposed in a vertical direction, each of word-lines coupled to the memory cells is set up to a respective target level during a word-line set-up period, a sensing operation on target memory cells is performed by applying a read voltage to a selected word-line coupled to the target memory cells while applying a read pass voltage to unselected word-lines during a sensing period, and while consuming an internal voltage connected to the unselected word-lines in a particular circuit in the nonvolatile memory device, a voltage level of the unselected word-lines is recovered to a level of the internal voltage during a discharge period of a word-line recovery period.