Single-Chip Push-Pull Magnetic Sensor Bridge Design

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Solution Overview

Problem

Current methods for manufacturing push-pull magnetic field sensor bridges, such as double deposition, multi-chip packaging, and laser-assisted local magnetic annealing, are complex, costly, and prone to performance inconsistencies, lacking standard methods for setting magnetization direction and resulting in high production costs and potential performance issues.

Innovation Solution

A single-chip push-pull magnetic field sensor bridge design using electrically interconnected magnetoresistive elements with permanent magnet strips to bias the magnetization direction, allowing for uniform magnetic bias fields and adjustable orientation to achieve consistent performance without the need for complex multi-chip assembly or specialized equipment.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If bridge-type magnetic field sensors are implemented using discrete components and integrated circuits, then the sensor functionality can be achieved, but the number of components increases and the chip area occupies more space

Engineering Contradiction:
Improvesensor functionalityVSAvoidnumber of components
Core Design Contradiction:
Ease of manufactureVSDevice complexity

Solution Approach 1:

The patent merges the magnetic field sensor elements, signal processing circuits, and evaluation logic into a single integrated sensor chip. The bridge-type magnetic field sensors are formed directly on the chip using semiconductor fabrication processes, and all necessary circuitry is integrated on the same substrate, eliminating the need for discrete components and multiple separate integrated circuits.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The sensor chip is designed to perform multiple functions: it contains the bridge-type magnetic field sensors for detecting magnetic flux density, integrated signal processing circuits for amplification and differentiation, and evaluation logic for determining rotational movement parameters. This multi-functional integration reduces the overall system complexity while maintaining full sensor functionality.

Inventive Principle:
Principle #6Universality (Multi-functionality)

2Ease of manufacture

If bridge-type magnetic field sensors are implemented using discrete components and integrated circuits, then the sensor functionality can be achieved, but the chip area occupied increases

Engineering Contradiction:
Improvesensor functionalityVSAvoidchip area
Core Design Contradiction:
Ease of manufactureVSArea of stationary object

Solution Approach 1:

The patent merges the magnetic field sensor elements, signal processing circuits, and evaluation logic into a single integrated sensor chip. The bridge-type magnetic field sensors are formed directly on the chip using semiconductor fabrication processes, and all necessary circuitry is integrated on the same substrate, eliminating the need for discrete components and multiple separate integrated circuits.

Inventive Principle:
Principle #5Merging (Combining)

3Measurement precision

If analog-to-digital conversion and signal evaluation are performed separately from the sensor elements, then signal processing can be achieved, but the overall device complexity increases

Engineering Contradiction:
Improvesignal processingVSAvoiddevice complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent merges the magnetic field sensor elements, signal processing circuits, and evaluation logic into a single integrated sensor chip. The bridge-type magnetic field sensors are formed directly on the chip using semiconductor fabrication processes, and all necessary circuitry is integrated on the same substrate, eliminating the need for discrete components and multiple separate integrated circuits.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The patent introduces an intermediary integrated circuit layer that bridges the sensor elements and the external evaluation system. This intermediary contains the analog-to-digital conversion and preliminary signal processing functions, reducing the complexity of the external evaluation system while maintaining high measurement precision through dedicated signal processing circuits integrated on the chip.

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

This design enables cost-effective, high-performance single-chip push-pull magnetic field sensor bridges with improved sensitivity and temperature stability, reducing production costs and ensuring consistent performance by uniformly biasing magnetization directions using permanent magnet strips.

Implementation Method 1

The sensor elements are formed as bridge-type magnetic field sensors having sensor elements which are formed in a bridge circuit configuration and have a magnetoresistive effect

Methodology Applied
Scientific EffectMagnetoresistive effect: Magnetoresistance

Data Source

PatentEP2696209B1Single-chip push-pull bridge-type magnetic field sensor
Publication Date: 2018.10.31 MULTIDIMENSION TECH CO LTD
  • EP2696209B1 patent drawingFigure 1~2
  • EP2696209B1 patent drawingFigure 3~4
  • EP2696209B1 patent drawingFigure 5~6

AI summary

The present invention discloses a design of a single-chip push-pull bridge sensor, composed of magnetoresistive elements, utilizing on-chip permanent magnets. The permanent magnets are oriented to preset magnetization directions of free layers of adjacent sensor bridge arms so that they point to different directions with respect the same sensing direction, enabling push-pull operation. The push-pull bridge sensor of the present invention is integrated on a single chip. Additionally, an on-chip coil is disclosed to reset or calibrate the magnetization directions of the free layers of the magnetoresistive elements.