Charge Pump Feedback Control for Nonvolatile Memory

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Solution Overview

Problem

Nonvolatile memory devices face challenges in reducing power consumption and size due to the operation of charge pumps, which generate high voltages required for operations like read and write, and also impact reliability with voltage ripple.

Innovation Solution

A nonvolatile memory device design that includes a charge pump controlled by feedback currents flowing through feedback bit lines, reducing the need for additional circuitry and using a one-stage voltage doubler to generate pump voltage, thereby minimizing size and power consumption while improving reliability.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Power

If a charge pump is incorporated to generate high voltage for memory operations, then the required high voltage is achieved, but power consumption increases

Engineering Contradiction:

Improvehigh voltage generation capabilityVSAvoidpower consumption

Core Design Contradiction:

PowerVSUse of energy by moving object

Solution Approach 1:

The patent implements feedback control by monitoring the actual pump voltage generated by the charge pump and comparing it with a target voltage. Based on this comparison, the control circuit adjusts the charge pump operation to maintain accurate voltage levels. This feedback mechanism enables precise voltage control while optimizing power consumption by avoiding over-generation of voltage.

Inventive Principle:

Principle #23Feedback

2Power

If a charge pump is incorporated to generate high voltage for memory operations, then the required high voltage is achieved, but device size increases

Engineering Contradiction:

Improvehigh voltage generation capabilityVSAvoiddevice size

Core Design Contradiction:

PowerVSArea of stationary object

Solution Approach 1:

The patent makes the charge pump circuit serve multiple functions: it generates the pump voltage for write operations, provides voltage boosting for read operations, and enables voltage level shifting for control signals. By making the charge pump multi-functional, the patent eliminates the need for separate voltage generation circuits for different operations, thereby reducing overall device size.

Inventive Principle:

Principle #6Universality (Multi-functionality)

3Power

If additional circuitry is added to control the charge pump, then high voltage generation is improved, but device size and power consumption increase

Engineering Contradiction:

Improvehigh voltage generation controlVSAvoidcontrol circuitry

Core Design Contradiction:

PowerVSDevice complexity

Solution Approach 1:

The patent combines the charge pump control functionality with the existing row decoder and column decoder circuits. The charge pump is controlled by control signals that are integrated into the normal memory operation control flow, eliminating the need for separate dedicated control circuitry. This merging approach reduces device complexity while maintaining effective charge pump control.

Inventive Principle:

Principle #5Merging (Combining)

4Power

If a charge pump operates to generate high voltage, then voltage level is achieved, but voltage ripple adversely impacts reliability

Engineering Contradiction:

Improvevoltage levelVSAvoidvoltage stability

Core Design Contradiction:

PowerVSReliability

Solution Approach 1:

Inventive Principle:

Principle #23Feedback

Solution Approach 2:

The patent dynamically adjusts the charge pump operating parameters (such as clock frequency and duty cycle) based on the desired voltage level and operational conditions. By changing these parameters adaptively, the system can generate the required voltage while minimizing ripple and improving voltage stability, thereby enhancing reliability.

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

The solution effectively reduces power consumption and size while enhancing reliability by accurately controlling the charge pump with feedback currents, eliminating voltage ripple and simplifying the charge pump structure, leading to improved performance and efficiency.

Implementation Method 1

a charge pump that generates a pump voltage provided to a selected word line among the word lines

Methodology Applied

Scientific EffectCapacitance: Capacitance

Data Source

PatentUS11217305B2Nonvolatile memory device and operating method

Publication Date: 2022.01.04 SAMSUNG ELECTRONICS CO LTD

AI summary

A nonvolatile memory device includes; a memory cell array including memory cells connected with bit lines and feedback cells connected with feedback bit lines, a row decoder connected with the memory cells and the feedback cells through word lines, a column decoder connected with the memory cells through the bit lines and connected with the feedback cells through the feedback bit lines, and a charge pump that generates a pump voltage provided to a selected word line among the word lines, wherein the charge pump is controlled in response to feedback currents flowing through the feedback bit lines.