Differential 3D Hall Sensor Layout for Precise Angular Sensing
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Solution Overview
Problem
Existing magnetic field sensors are limited in their ability to measure magnetic field changes in three dimensions, particularly in XY, XZ, and YZ planes, leading to inaccuracies in detecting angular positions and movements of rotating magnets.
Innovation Solution
A magnetic field sensor is designed with Hall element clusters configured to differentially sense in three dimensions, utilizing first and second dies with orthogonal planes of sensitivity, providing differential sensing in XY, XZ, and YZ planes, and incorporating a sensing controller to manage Hall element activation for redundancy and power efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If traditional single-plane Hall element sensors are used, then device complexity is reduced, but measurement precision in three dimensions deteriorates
Solution Approach 1:
The sensor is divided into multiple Hall element clusters arranged in different planes (first plane, second plane, and third plane perpendicular to both). Each cluster measures magnetic field components in its specific plane, and the combined output from all clusters provides comprehensive 3D measurement capability, resolving the contradiction by segmenting the sensing function across multiple specialized units.
Solution Approach 2:
The invention transitions from single-plane 2D sensing to three-plane 3D sensing by adding Hall element clusters in orthogonal planes. This dimensional expansion allows the sensor to capture magnetic field variations in all three spatial dimensions simultaneously, achieving full 3D measurement precision without excessive complexity through systematic geometric arrangement.
2Adaptability or versatility
If multiple Hall element clusters in orthogonal planes are implemented, then 3D sensing capability is improved, but device complexity increases
Solution Approach 1:
The multiple Hall element clusters arranged in orthogonal planes serve multiple functions simultaneously: they detect linear movements in stroke, side shaft, and end of shaft configurations; they measure angular positions; and they provide redundant sensing paths. This multi-functionality approach allows a single sensor structure to handle diverse 3D sensing requirements, improving adaptability without proportionally increasing complexity.
3Reliability
If redundant Hall element clusters are added, then reliability is improved, but use of energy increases
Solution Approach 1:
The sensing controller implements periodic or selective activation of Hall element clusters based on the specific sensing task required. Instead of continuously powering all Hall elements, the controller activates only the necessary clusters for the current measurement mode (e.g., only XY plane elements for 2D rotation, or specific clusters for linear stroke sensing), thereby maintaining reliability through selective redundancy while significantly reducing power consumption.
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 sensor achieves accurate detection of linear and rotational movements in three dimensions, offering improved stray field immunity and redundancy, enhancing the precision and reliability of angular position sensing.
Implementation Method 1
magnetic field sensors may measure change in a magnetic field due to a moving target
Data Source
AI summary
Method and apparatus for a 3D sensor having die Hall element clusters located on first and second die. In an embodiment, a sensor IC package includes a first die having first, second, and third Hall clusters having different axes of magnetic field sensitivity and a second die having a fourth Hall cluster having sensitivity in the first and third axes of sensitivity. The sensor provides 3D field sensing for stroke, end of shaft and side shaft sensing applications.