Flash Memory Dual Supply Operation via Internal Voltage Generation

Solution Overview

Problem

Flash memory devices face challenges in operating with dual supply voltages, particularly when confined to small packages with limited pins, as they need to interface with both high and low supply voltage integrated circuits without additional pins for a second supply voltage.

Innovation Solution

A flash memory device with a selectable-level buffer and internal supply voltage generator that can operate at either external or internally generated supply voltages, allowing flexibility in interfacing with either low or high supply voltage integrated circuits, and the option to receive an external second supply voltage for dual supply operation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If a flash memory device uses two separate supply pins (VDD and VDDQ) for dual supply operation, then voltage compatibility with different integrated circuits is improved, but the device complexity and package pin requirements increase

Engineering Contradiction:

Improvevoltage compatibilityVSAvoidpin requirements

Core Design Contradiction:

Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The single supply pin VDD is designed to serve multiple functions: it can provide high supply voltage directly to I/O buffers when external high voltage circuits are used, or it can be internally converted to low supply voltage for I/O buffers when external low voltage circuits are used. This multi-functionality eliminates the need for separate VDD and VDDQ pins while maintaining dual supply operation capability.

Inventive Principle:

Principle #6Universality (Multi-functionality)

Solution Approach 2:

The flash memory device includes an internal supply voltage generator that automatically converts the high supply voltage from VDD to a lower internal supply voltage when needed. This self-service mechanism allows the device to generate its own low voltage supply internally without requiring an external low voltage pin, reducing pin requirements while maintaining voltage compatibility.

Inventive Principle:

Principle #25Self-service

2Adaptability or versatility

If the flash memory device operates with a single supply pin at high voltage, then pin limitations are reduced, but the ability to interface with low supply voltage integrated circuits is lost

Engineering Contradiction:

Improveinterface compatibilityVSAvoidinternal voltage generation

Core Design Contradiction:

Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The internal supply voltage generator acts as an intermediary between the high voltage supply pin VDD and the low voltage I/O buffers. It converts the high supply voltage to a lower internal supply voltage, enabling the I/O buffers to interface with low voltage integrated circuits while the device continues to use a single high voltage supply pin.

Inventive Principle:

Principle #24Intermediary (Mediator)

3Adaptability or versatility

If dual supply pins are used for flexible voltage operation, then adaptability to different systems is improved, but the package size and pin count increase

Engineering Contradiction:

Improvesystem compatibilityVSAvoidpackage size

Core Design Contradiction:

Adaptability or versatilityVSVolume of moving object

Solution Approach 1:

The single supply pin VDD is designed to serve multiple functions: it can provide high supply voltage directly to I/O buffers when external high voltage circuits are used, or it can be internally converted to low supply voltage for I/O buffers when external low voltage circuits are used. This multi-functionality eliminates the need for separate VDD and VDDQ pins while maintaining dual supply operation capability.

Inventive Principle:

Principle #6Universality (Multi-functionality)

Solution Approach 2:

The flash memory device includes an internal supply voltage generator that automatically converts the high supply voltage from VDD to a lower internal supply voltage when needed. This self-service mechanism allows the device to generate its own low voltage supply internally without requiring an external low voltage pin, reducing pin requirements while maintaining voltage compatibility.

Inventive Principle:

Principle #25Self-service

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

Enables flexible operation with dual supply voltages in small packages, ensuring compatibility with various integrated circuits and enhancing performance by allowing internal voltage generation and external voltage sourcing, thus overcoming pin limitations and voltage compatibility issues.

Implementation Method 1

a supply voltage generator coupled to the internal power bus for generating an internal voltage from the first supply voltage

Methodology Applied

Scientific EffectVoltage generation:

Data Source

PatentUS9275738B2Flash memory having dual supply operation

Publication Date: 2016.03.01 WINBOND ELECTRONICS CORP

AI summary

A flash memory device may operate from two supply voltages, one being provided externally, and the other being generated within the flash memory device from the external supply voltage. The flash memory device may be provided with a selectable-level buffer for interfacing with either low supply voltage or high supply voltage integrated circuits. To provide even greater flexibility, the flash memory device may be provided with the capability of receiving a second supply voltage from an external source, which may take precedence over the internally-generated second supply voltage or may be combined with the internally-generated second supply voltage.