학술논문

A Stray-Field-Immune Magnetic Displacement Sensor With 1% Accuracy
Document Type
Periodical
Source
IEEE Sensors Journal IEEE Sensors J. Sensors Journal, IEEE. 20(19):11405-11411 Oct, 2020
Subject
Signal Processing and Analysis
Communication, Networking and Broadcast Technologies
Components, Circuits, Devices and Systems
Robotics and Control Systems
Magnetic sensors
Magnetic field measurement
Magnetic domains
Mechanical sensors
Magnetostriction
Magnetic fields
Automotive electronics
Hall effect
magnetic sensors
Language
ISSN
1530-437X
1558-1748
2379-9153
Abstract
We present a new Hall sensor design for the accurate and robust measurement of linear displacement. Implemented in CMOS, the sensor is based on a novel gradient measurement concept combining Hall elements with integrated magnetic concentrators. In typical applications with practical Ferrite magnets, the peak output voltage of the Hall transducers is only around 1.7 mV at the maximum operating temperature of 160°C, and thus requires high-performance low-offset readout electronics. Over its 15-mm linear displacement range, the sensor’s total error is 1% including manufacturing tolerances, trimming accuracy, temperature, aging effects, and practical magnet constraints. In addition, the sensor is immune to magnetic stray fields up to 5 mT, complying with the most stringent automotive norm.