Page Buffer With Segmented Precharge Circuits For Nonvolatile Memory

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Solution Overview

Problem

As semiconductor memory devices integrate, interferences between neighboring sensing nodes in nonvolatile memory devices increase, leading to sensing errors and degradation of memory cell distributions.

Innovation Solution

A page buffer circuit with a first precharge circuit for bitlines and a second precharge circuit for sensing nodes, electrically separated from the first path, allows for unconditional precharge of bitlines and selective precharge of sensing nodes based on memory cell states, reducing interference and enhancing sensing accuracy.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Quantity of substance

If integration of nonvolatile memory devices is increased, then device density and capacity are improved, but interferences between neighboring sensing nodes increase causing sensing errors

Engineering Contradiction:

Improvedevice densityVSAvoidsensing accuracy

Core Design Contradiction:

Quantity of substanceVSReliability

Solution Approach 1:

The patent divides the precharging function into two separate circuits: a first precharge circuit for bitlines and a second precharge circuit for sensing nodes. This segmentation allows independent control and optimization of each precharging operation, reducing interference between neighboring sensing nodes while maintaining high device density.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent performs preliminary precharging of sensing nodes through the second precharge circuit before the actual sensing operation. This preliminary action ensures that sensing nodes are properly initialized and isolated from interference, improving sensing accuracy in high-density configurations.

Inventive Principle:

Principle #10Preliminary action

2Quantity of substance

If integration of nonvolatile memory devices is increased, then device density is improved, but sensing errors increase due to interference between sensing nodes

Engineering Contradiction:

Improvedevice densityVSAvoidsensing precision

Core Design Contradiction:

Quantity of substanceVSMeasurement precision

Solution Approach 1:

The patent segments the precharging function into two independent circuits, allowing the second precharge circuit to specifically target sensing nodes with tailored precharging operations. This segmentation enables precise control over sensing node voltages, maintaining sensing precision despite increased device density.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent applies different precharging strategies to different parts of the system: the first precharge circuit handles bitlines with one approach, while the second precharge circuit handles sensing nodes with a different approach. This local quality differentiation ensures optimal precharging for each component, preserving sensing precision in high-density devices.

Inventive Principle:

Principle #3Local quality

3Device complexity

If a single precharge circuit is used for both bitlines and sensing nodes, then device complexity is reduced, but interference between neighboring sensing nodes increases

Engineering Contradiction:

Improvecircuit complexityVSAvoidsensing node interference

Core Design Contradiction:

Device complexityVSObject-generated harmful factors

Solution Approach 1:

The patent divides the precharge function into two separate circuits, which increases device complexity but eliminates sensing node interference. The first precharge circuit handles bitlines while the second precharge circuit exclusively manages sensing nodes, preventing harmful interference despite the added complexity.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent extracts the sensing node precharging function from the bitline precharge circuit and places it in a dedicated second precharge circuit. This extraction removes the source of interference between neighboring sensing nodes, addressing the harmful effect despite increasing overall circuit complexity.

Inventive Principle:

Principle #2Taking out (Extraction)

Data Source

PatentUS10204686B2Page buffer, method of sensing a memory cell using the same, and nonvolatile memory device including the same

Publication Date: 2019.02.12 SAMSUNG ELECTRONICS CO LTD

AI summary

A page buffer includes a first precharge circuit, a second precharge circuit, and a sense amplifying circuit. The first precharge circuit includes a first path for precharging a bitline connected to a nonvolatile memory cell. The second precharge circuit includes a second path for precharging a sensing node connected to the bitline. The second path is electrically separated from the first path. The sensing node is used to detect a state of the nonvolatile memory cell. The sense amplifying circuit is connected to the sensing node and the second precharge circuit, and stores state information representing the state of the nonvolatile memory cell. The second precharge circuit is configured to perform a first precharge operation for the sensing node and configured to selectively perform a second precharge operation for the sensing node based on the state of the nonvolatile memory cell after the first precharge operation.