MR-SOT Magnetic Field Sensor for 360° Angle Drift Compensation

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Solution Overview

Problem

Existing angle sensors, particularly MR sensors, suffer from lifetime drift due to changes in magnetization direction, leading to phase drift and additional angle errors, which are not adequately addressed by current technologies.

Innovation Solution

Combining an MR sensor component with a spin-orbit torque (SOT) sensor component to redundantly measure the magnetic field, with the SOT component compensating for the lifetime drift of the MR component, thereby maintaining accurate angle measurements over time.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If MR sensor technology (GMR/TMR) is used to achieve full 360 degree periodicity, then measurement range is improved, but lifetime drift occurs due to complex multilayered sensor element stack

Engineering Contradiction:

Improvemeasurement rangeVSAvoidlifetime drift

Core Design Contradiction:

Adaptability or versatilityVSReliability

Solution Approach 1:

The sensor is divided into two independent components: an MR sensor component for primary measurement and a SOT sensor component for drift compensation. Each component has a simpler structure than a full GMR/TMR sensor, but together they achieve the functionality while reducing lifetime drift through the SOT component's stability.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The SOT sensor component acts as an intermediary that measures lifetime drift independently and provides compensation data. The SOT component's different measurement principle and structural simplicity allow it to serve as a stable reference for correcting MR sensor drift over time.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Reliability

If AMR-based angle sensors are used to achieve negligible lifetime drift, then reliability is improved, but measurement range is limited to 180 degree periodicity

Engineering Contradiction:

Improvelifetime driftVSAvoidmeasurement range

Core Design Contradiction:

ReliabilityVSAdaptability or versatility

Solution Approach 1:

The patent combines AMR-based SOT sensor component with another sensor component to create a hybrid system. The SOT component provides stable lifetime performance with 180 degree periodicity, while the combination with the additional component extends the overall measurement capability to full 360 degree periodicity.

Inventive Principle:

Principle #5Merging (Combining)

3Adaptability or versatility

If GMR- or TMR-angle sensors are used to achieve full 360 degree periodicity, then measurement range is improved, but manufacturing complexity increases due to complex multilayered sensor element stack

Engineering Contradiction:

Improvemeasurement rangeVSAvoidsensor element stack

Core Design Contradiction:

Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The complex GMR/TMR sensor structure is segmented into separate functional components. Instead of using a single complex multilayered stack, the system uses simpler MR and SOT sensor components that can be manufactured separately and integrated, reducing overall manufacturing complexity while maintaining measurement capabilities.

Inventive Principle:

Principle #1Segmentation

4Measurement precision

If MR sensor component is used to achieve high field sensitivity, then measurement precision is improved, but lifetime phase drift occurs due to change in magnetization direction

Engineering Contradiction:

Improvefield sensitivityVSAvoidlifetime phase drift

Core Design Contradiction:

Measurement precisionVSReliability

Solution Approach 1:

The SOT sensor component provides continuous feedback on lifetime drift characteristics. By independently measuring the magnetic field with a different physical principle, the SOT component enables detection and compensation of phase drift in the MR sensor, maintaining long-term measurement accuracy.

Inventive Principle:

Principle #23Feedback

Solution Approach 2:

The system changes the measurement parameters by using two different sensor types with different physical principles (MR and SOT). This allows the system to operate in a parameter space where both high sensitivity (from MR) and long-term stability (from SOT) can be achieved through coordinated measurement and compensation.

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 combination of MR and SOT sensor components provides a cost-effective solution with full 360-degree periodicity, reducing lifetime drift and maintaining sensor performance, similar to GMR/TMR sensors but with improved stability and reduced complexity.

Implementation Method 1

magnetoresistance sensors (MR)

Methodology Applied

Scientific EffectMagnetoresistance: Magnetoresistance

Implementation Method 2

spin-orbit torque (SOT) sensor component

Methodology Applied

Scientific EffectSpin-orbit torque:

Data Source

PatentUS12366616B2Magnetic field sensor, method for producing same, and method for measuring a magnetic field

Publication Date: 2025.07.22 INFINEON TECHNOLOGIES AG

AI summary

The present disclosure relates to a magnetic field sensor, in particular an angle sensor, including a magnetoresistive sensor component and a spin-orbit torque, SOT, sensor component.