Spin-Based ADC Using Magnetoresistive Comparators

Solution Overview

Problem

Conventional transistor-based flash analog-to-digital converters (ADCs) consume high power and occupy large chip areas, limiting their efficiency and resolution.

Innovation Solution

The use of magnetoresistive devices as comparators in spin-based ADCs, which require less power and area, allowing for faster and more efficient analog-to-digital conversion by utilizing spin-currents to set magnetization states for digital representation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Speed

If transistor-based comparators are used in flash ADCs, then high-speed conversion is achieved, but power consumption increases and chip area expands

Engineering Contradiction:

Improveconversion speedVSAvoidpower consumption

Core Design Contradiction:

SpeedVSUse of energy by moving object

Solution Approach 1:

The patent replaces transistor-based comparators with magnetoresistive device-based comparators. This substitution uses magnetic field effects and spin-current mechanisms instead of conventional transistor switching, achieving comparable high-speed performance while significantly reducing power consumption and chip area requirements.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The invention changes the fundamental operating parameters of the comparator by using magnetoresistive devices with different resistance states (high and low resistance) to represent binary values. This parameter change from voltage-based transistor switching to resistance-based magnetic state comparison enables lower power operation while maintaining fast conversion speeds.

Inventive Principle:

Principle #35Parameter changes

2Speed

If transistor-based comparators are used in flash ADCs, then high-speed conversion is achieved, but chip area increases

Engineering Contradiction:

Improveconversion speedVSAvoidchip area

Core Design Contradiction:

SpeedVSArea of stationary object

Solution Approach 1:

The patent replaces transistor-based comparators with magnetoresistive device-based comparators. This substitution uses magnetic field effects and spin-current mechanisms instead of conventional transistor switching, achieving comparable high-speed performance while significantly reducing power consumption and chip area requirements.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The invention employs composite magnetic tunnel junction structures consisting of multiple ferromagnetic layers separated by thin insulating barriers. This composite material approach enables compact device fabrication with high-density integration, reducing the overall chip area while maintaining fast switching capabilities.

Inventive Principle:

Principle #40Composite materials

3Use of energy by stationary object

If magnetoresistive devices are used as comparators, then power consumption and chip area are reduced, but manufacturing complexity increases

Engineering Contradiction:

Improvepower consumptionVSAvoidmanufacturing complexity

Core Design Contradiction:

Use of energy by stationary objectVSEase of manufacture

Solution Approach 1:

The invention changes the fundamental operating parameters of the comparator by using magnetoresistive devices with different resistance states (high and low resistance) to represent binary values. This parameter change from voltage-based transistor switching to resistance-based magnetic state comparison enables lower power operation while maintaining fast conversion speeds.

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent introduces reference voltages as intermediary elements that facilitate the comparison process. By using reference voltages applied to magnetoresistive devices, the system enables straightforward determination of magnetization states through simple resistance measurements, simplifying the overall manufacturing and operation despite the advanced device physics involved.

Inventive Principle:

Principle #24Intermediary (Mediator)

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 spin-based ADCs achieve lower power consumption and smaller chip area while maintaining high sampling rates and non-volatile storage capabilities, enabling higher resolution and scalability compared to traditional flash ADCs.

Implementation Method 1

a conductive layer configured to output a spin-current based on an analog input value

Methodology Applied

Scientific EffectSpin-current: Spin Coating

Implementation Method 2

The magnetization state of each of the magnetoresistive devices is set by respective reference voltages and the spin-current

Methodology Applied

Scientific EffectMagnetization state: Magnetism

Data Source

PatentUS9240799B1Spin-based logic device

Publication Date: 2016.01.19 REGENTS OF THE UNIVERSITY OF MINNESOTA

AI summary

A device including a conductive layer configured to output a spin-current based on an analog input value, a plurality of magnetoresistive devices, and an encoder configured to output a digital value. Each of the magnetoresistive devices may be configured to receive a different reference voltage on a first side and the spin-current on a second side. The magnetization state of each of the magnetoresistive devices is set by respective reference voltages and the spin-current. The encoder may include a plurality of digital bits that is a digital representation of the analog input value based on the magnetization states of the magnetoresistive devices.