Threshold Gate With Magnetic Tunnel Junction For Logic Density

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Solution Overview

Problem

Integrated circuits (ICs) require numerous Boolean gates to implement complex Boolean functions, leading to increased space, power consumption, and volatility, as they cannot store outputs when power is off.

Innovation Solution

Threshold gates utilizing a magnetic tunnel junction (MTJ) element, which is switchable between non-volatile resistive states, implement threshold functions, reducing the number of gates needed and providing compact, fast, and space-efficient operation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If numerous Boolean gates are used to implement complex Boolean functions, then the functionality is achieved, but the space required increases

Engineering Contradiction:

ImproveBoolean function implementation capabilityVSAvoidIC space

Core Design Contradiction:

Adaptability or versatilityVSArea of stationary object

Solution Approach 1:

The patent merges multiple Boolean gate functions into a single threshold gate by using a threshold logic element that evaluates multiple inputs against a threshold value. This consolidation reduces the number of discrete gates needed, directly addressing the space consumption problem while maintaining complex Boolean function implementation capability.

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The threshold gate serves as a universal logic element that can implement various Boolean functions (AND, OR, NAND, NOR, XOR, etc.) by adjusting threshold values and input weights. This multi-functionality allows a single gate type to replace multiple specialized gates, reducing overall IC space requirements.

Inventive Principle:

Principle #6Universality (Multi-functionality)

2Adaptability or versatility

If numerous Boolean gates are used to implement complex Boolean functions, then the functionality is achieved, but the power consumption increases

Engineering Contradiction:

ImproveBoolean function implementation capabilityVSAvoidIC power consumption

Core Design Contradiction:

Adaptability or versatilityVSUse of energy by stationary object

Solution Approach 1:

By combining multiple gate operations into a single threshold gate evaluation, the patent reduces the total number of switching operations required. Fewer switches mean less dynamic power consumption, directly addressing the power efficiency problem while maintaining full Boolean function capability.

Inventive Principle:

Principle #5Merging (Combining)

3Adaptability or versatility

If numerous Boolean gates are used to implement complex Boolean functions, then the functionality is achieved, but the circuit speed decreases

Engineering Contradiction:

ImproveBoolean function implementation capabilityVSAvoidoutput generation speed

Core Design Contradiction:

Adaptability or versatilityVSSpeed

Solution Approach 1:

The patent merges multiple sequential gate delays into a single threshold evaluation operation. Since the threshold gate evaluates all inputs simultaneously against a threshold rather than propagating signals through multiple gate stages, the overall propagation delay is reduced, improving circuit speed while maintaining complex logic functionality.

Inventive Principle:

Principle #5Merging (Combining)

4Adaptability or versatility

If Boolean gates are used, then the logic function is implemented, but the output cannot be stored when power is turned off due to volatility

Engineering Contradiction:

ImproveBoolean function implementation capabilityVSAvoidoutput storage capability

Core Design Contradiction:

Adaptability or versatilityVSReliability

Solution Approach 1:

The patent introduces a magnetic tunnel junction (MTJ) element as an intermediary between the threshold logic element and the output. The MTJ provides non-volatile memory capability, storing the threshold gate output state even when power is removed. This mediator enables the system to maintain both fast threshold logic operation and reliable non-volatile storage.

Inventive Principle:

Principle #24Intermediary (Mediator)

5Reliability

If a magnetic tunnel junction (MTJ) element is used to provide non-volatile storage, then output storage capability is improved, but the device complexity increases

Engineering Contradiction:

Improveoutput storage capabilityVSAvoidthreshold gate structure

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The patent merges the threshold logic function and non-volatile storage function into a single integrated threshold gate structure. The MTJ element is directly coupled to the threshold logic element, combining computation and memory functions in one device unit. This integration reduces overall system complexity compared to separate logic and memory components.

Inventive Principle:

Principle #5Merging (Combining)

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

Threshold gates can generate outputs similar to complex Boolean functions with fewer gates, offering improved compactness, speed, and power efficiency while maintaining non-volatile storage of outputs.

Implementation Method 1

a magnetic tunnel junction (MTJ) element. The MTJ element is switchable from a first resistive state to a second resistive state

Methodology Applied

Scientific EffectMagnetic tunnel junction effect: Magnetoresistance

Data Source

PatentUS9306151B2Threshold gate and threshold logic array

Publication Date: 2016.04.05 THE ARIZONA BOARD OF REGENTS ON BEHALF OF THE UNIV OF ARIZONA

AI summary

Threshold gates and related circuitry are disclosed. In one embodiment, a threshold gate includes a threshold realization element and a magnetic tunnel junction (MTJ) element. The MTJ element is switchable from a first resistive state to a second resistive state. To realize a threshold function with the MTJ element, the threshold realization element is configured to switch the magnetic tunnel junction element from the first resistive state to the second resistive state in accordance with the threshold function. In this manner, the threshold gate may implement a threshold function that provides an output just like a complex Boolean function requiring several Boolean gates.