Polygonal Vertical Hall Sensor for Fast Magnetic Field Direction
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Solution Overview
Problem
Conventional circular vertical Hall (CVH) magnetic field sensors are limited in their ability to rapidly identify the direction of a magnetic field and provide low angular resolution, requiring substantial time to generate output signals from multiple vertical Hall elements sequentially.
Innovation Solution
A magnetic field sensor featuring a semiconductor substrate with primary and secondary vertical Hall elements arranged in a polygonal pattern, coupled with an electronic circuit that switches between groups of vertical Hall elements to generate simultaneous output signals, allowing for faster determination of the magnetic field angle.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If multiple vertical Hall elements are arranged in a circular pattern (CVH sensing element), then the sensor can determine the direction of a magnetic field in a plane, but it requires substantial time to generate all output signals sequentially
Solution Approach 1:
The sensor divides the circular array of vertical Hall elements into multiple groups, where each group contains a subset of the Hall elements. The electronic circuit selectively activates different groups at different times, allowing parallel processing of multiple Hall element outputs. This segmentation enables faster signal generation while maintaining the angular resolution benefits of having multiple distributed sensing elements.
2Productivity
If all output signals from vertical Hall elements are generated sequentially, then the sensor structure remains simple, but the determination of magnetic field direction takes substantial time
Solution Approach 1:
The electronic circuit implements dynamic group selection, where different groups of vertical Hall elements are selectively activated at different times based on the sampling phase. This dynamic switching allows the system to process multiple Hall element signals in parallel across different time slots, significantly increasing the speed of magnetic field direction identification while managing circuit complexity through time-multiplexed operation.
3Measurement precision
If a circular arrangement of vertical Hall elements is used, then the sensor can provide angular measurement, but the angular step size (resolution) is limited
Solution Approach 1:
The sensor uses more vertical Hall elements than would be minimally required for basic angular measurement. By dividing these elements into multiple groups and selectively activating different groups at different times, the system achieves finer angular resolution (smaller angular step size) while maintaining high sampling speed. The partial activation of element groups at any given time allows the circuit to process signals faster while the overall set of elements provides high precision measurement capability.
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 configuration enables faster generation of output signals indicative of the magnetic field angle, reducing the time required to identify the direction and improving angular resolution compared to traditional CVH sensors.
Implementation Method 1
A vertical Hall element tends to be responsive to magnetic field parallel to a surface of a substrate on which the vertical Hall element is formed
Data Source
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AI summary
A magnetic field sensor (100) has a plurality of vertical Hall elements (102a, 102b, 102c, 102d,102e,102e,102f) arranged in at least a portion of a polygonal shape. The magnetic field sensor includes an electronic circuit (108) to process signals generated by the plurality of vertical Hall elements to identify a direction of a magnetic field (109). A corresponding method of fabricating the magnetic field sensor is also described.