Integrated CVH and Planar Hall Sensor for 3D Magnetic Field Sensing
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Solution Overview
Problem
Current magnetic field sensing technologies require multiple sensors and complex processing to detect three-dimensional magnetic field characteristics, which is cumbersome, expensive, and prone to alignment inaccuracies.
Innovation Solution
A single integrated magnetic field sensing element combining circular vertical Hall and planar Hall elements on a silicon substrate, generating signals indicative of three-dimensional magnetic field characteristics, including direction and magnitude, through a processing circuit that processes signals from both types of Hall elements.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If both a two-dimensional magnetic field sensor and a one-dimensional magnetic field sensor are used to resolve three-dimensional characteristics, then measurement precision is improved, but device complexity increases
Solution Approach 1:
The patent combines a circular vertical Hall (CVH) sensor and a planar Hall (PH) sensor into a single integrated device. The CVH sensor measures magnetic field components in the plane perpendicular to the substrate, while the PH sensor measures the component parallel to the substrate. By merging these two sensor types into one integrated structure, the patent achieves three-dimensional magnetic field sensing without requiring separate sensor assemblies, thereby reducing device complexity while maintaining measurement precision.
Solution Approach 2:
The integrated sensor performs multiple functions: the CVH element provides two-dimensional sensing in the vertical plane, the PH element provides one-dimensional sensing in the horizontal plane, and together they deliver complete three-dimensional magnetic field characterization. This multi-functional design eliminates the need for multiple separate sensors and simplifies the overall system architecture.
2Measurement precision
If both a two-dimensional magnetic field sensor and a one-dimensional magnetic field sensor are used, then measurement precision is improved, but manufacturing cost increases
Solution Approach 1:
The patent integrates both CVH and PH sensor elements on a single substrate, allowing them to be manufactured together in the same production run. This combined manufacturing approach eliminates the need to produce, test, and assemble separate two-dimensional and one-dimensional sensors, significantly reducing manufacturing costs while achieving three-dimensional sensing capability.
3Measurement precision
If both a two-dimensional magnetic field sensor and a one-dimensional magnetic field sensor are used, then measurement precision is improved, but alignment accuracy deteriorates
Solution Approach 1:
By integrating the CVH and PH sensor elements on the same substrate during the same manufacturing process, the patent eliminates the alignment problems that arise when using separate sensors. The elements are fabricated in fixed geometric relationships to each other, ensuring precise orientation without requiring post-manufacturing alignment procedures.
4Measurement precision
If additional processing is performed to resolve three-dimensional characteristics from two sensors, then measurement precision is improved, but device complexity increases
Solution Approach 1:
The integrated sensor structure combines the CVH and PH elements with their respective processing circuits in a unified device. The output signals from both sensor types are available simultaneously and can be processed together to directly obtain three-dimensional magnetic field characteristics, simplifying the overall processing architecture compared to separate sensor systems.
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 solution provides accurate and cost-effective three-dimensional magnetic field sensing by integrating sensors on a single substrate, simplifying alignment and reducing the need for multiple sensors and complex processing.
Implementation Method 1
circular vertical Hall (CVH) sensing element... configured to generate a plurality of x-y output signals in response to a magnetic field having a direction component in an x-y plane parallel to the first major surface of the substrate
Implementation Method 2
planar Hall elements... configured to generate a plurality of z output signals in response to a magnetic field having a direction component in a z direction orthogonal to the x-y plane
Data Source
Figure 1
Figure 2~2A
Figure 2B
AI summary
A magnetic field sensor (10;40) includes a circular vertical Hall (CVH) sensing element (12; 48) and at least one planar Hall element (18; 47 ). The CVH sensing element has contacts (14a,14b,14c,14d,14e) arranged over a common implant region (16;42) in a substrate (22;50). In some embodiments, the at least one planar Hall element is formed as a circular planar Hall (CPH) sensing element (46) also having contacts disposed over the common implant region (42). A CPH sensing element (46) and a method of fabricating the CPH sensing element are separately described