Hostname: page-component-7dd5485656-bvgqh Total loading time: 0 Render date: 2025-10-31T07:07:26.076Z Has data issue: false hasContentIssue false
  • English
  • Français

Magnetic Field Sensors for Magnetic Position Sensing in Automotive Applications

Published online by Cambridge University Press:  10 February 2011

Joseph P. Heremans
Joseph P. Heremans*
Affiliation:
General Motors R&D Center M. S. 480–106–224, 30500 Mound Rd., Warren, MI 48090–9055
Get access

Abstract

Magnetic position sensors are transducers whose output is an electrical signal that is a function of a mechanical motion. They consist of a permanent magnet, a magnetic field sensor, and a moving magnetic circuit. Being contactless, they do not wear out. Unlike optical systems, they are impervious to contamination. With the proliferation of microprocessor control in many on-board automotive applications, magnetic position sensing becomes a crucial function, found e.g. in cam and crankshaft sensors used for ignition timing and engine misfire detection, in brushless electrical motors, in wheel speed sensors and in other applications.

This paper first reviews the requirements put on the magnetic field sensors in these applications. Five main types of field sensors are used: Si Hall sensors with integrated amplifiers, GaAs Hall sensors, InSb-based magnetoresistors, anisotropie magnetoresistors (AMR), and metal-multilayer magnetoresistors (GMR). Magnetoresistors are almost always used as differential pairs, either in Wheatstone bridges or with matched constant current sources. The two characteristics of each type of field sensors that matter most are their sensitivity to magnetic field, and the smallest amount of field modulation they can detect, i.e. their resolution, which is mainly limited by the drift of the outputs with temperature. These parameters are measured and reported here on the 5 types of sensors; the work is an update of a 1993 review by the author.

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

Article purchase

Temporarily unavailable

References

REFERENCES

1. Weiss, H., Structure and Applications of Galvanomagnetic Devices, Pergamon Press, Oxford, 1969 Google Scholar
2. Magnetic Sensors, Data Book, Siemens Aktiengesellschaft, Baianstrasse 73, D-8000 Muenchen, Germany, 1989 and 1996 Google Scholar
3. Heremans, J., Magnetic Devices, Encyclopedia of Applied Physics, VCH Publishers Inc., 1993 Google Scholar
4. Heremans, J., Solid state magnetic field sensors and applications, J. Phys. D: Appl. Phys 26 1149(1993)Google Scholar
5. Ota, K. and Hashimoto, T., Society of Automotive Engineers, Transaction No. 930551 (1993)Google Scholar
6. Mani, R.G. and von Klitzing, K., Appl. Phys. Lett. 64 3121 (1994),Google Scholar
Mani, R.G., von Klitzing, K., Jost, F., Marx, K., Lindenkreuz, S. and Trah, H. P., Appl. Phys. Lett. 67 2223 (1995)Google Scholar
7. Data sheet 27501.1, and Integrated and Discrete Semiconductors, Data Book, Allegro Microsystems, Inc., 115 Northeast Cutoff, Box 15036, Worchester, MA 01615, USA, 1995 Google Scholar
8. EMCORE Corporation, 394 Elizabeth Ave., Somerset, NJ 08873, USAGoogle Scholar
9. Heremans, J., Semicond. Sci. Technol. 8 S424 (1993)Google Scholar
10. Honeywell, Magnetic Products, Solid State Electronics Center, 12001 State Highway 55, Plymouth, MN 55441, USAGoogle Scholar
11. Integrated GMR Magnetic Sensors, NVSI, Nonvolatile Electronics Inc., 11409 Valley View Road, Eden Prairie, MN 55344Google Scholar
12. Partin, Dale L. and Heremans, Joseph P., U.S. Patent No. 5,184,106 (2 Feb. 1993)Google Scholar
13. Partin, Dale L. and Heremans, Joseph P., U.S. Patent No 5,153,557 (6 Oct. 1992)Google Scholar