Anisotropic Magneto-Resistive or AMR sensors are magnetic sensors that are precise and contact-less measuring the changes in the angle of a magnetic field as seen by the sensor. TE Connectivity's (TE) magnetic position sensors offer robust non-contact position measurements in harsh environments. For example, the unique features of the AMR effect allow the detection of tiny disturbances in the earth's magnetic field created by cars in traffic detection sensors, as well as the measurement of sub-micrometer displacements in precision linear encoders. The AMR sensor technology is also successfully used for presence detection, such as the end-point detection in pneumatic cylinders.
Learn about magnetoresistive sensor technology, the features and benefits of the KMXP series, and the various applications and industries in which the sensor can be used.
Andreas Voss presents details on magnetoresistive sensor technology and where the sensor technology can be applied.
| Application |
Feature |
Benefit |
|---|---|---|
| Surgical Robots |
Small size |
Allows for compact, reliable designs |
| Contactless position measurements | Provides for reliable sensing in demanding applications and long life | |
| Prosthetics |
Linear and rotational detection |
Provides adjustable position measurement |
| Protects the sensing elements from electromagnetic interference | Can be used in high EMF environments without extra protection | |
| Syringe and Infusion Pumps |
10-50 µm accuracy with sub µm resolution for linear use |
Allows for precise control of fluids |
| DFN solderable packaging or SMT | Provides cost-effective reliable designs | |
| Medical Tables & Chairs |
Can determine linear or angular position |
Provides flexible position measurement |
| Simple electronic interface; standard electronics available | Keeps costs low and provides good accuracy | |
| Machine Tools |
Ease of manufacturing and integration |
Provides cost-effective reliable designs |
| Not susceptible to EMC | Can be used in high EMF environments without extra protection | |
| Cutting Tools |
Suitable for high-accuracy applications |
Allows for precise cutting of materials |
| Provides long life even in the toughest environments | High reliability, minimizes warranty issues | |
| Semiconductor Handling Equipment | Good for high-temperature applications | Reliable operation over a broad temperature range |
| Suitable for small spaces | Enables the creation of compact, reliable designs. |
Q: What type of MR applications is the KMXP series suitable for?
A: The KMXP series is suitable for pole wheel applications for rotational measurements and for magnetic scale applications for linear measurements.
Q: What is the internal construction of the sensor?
A: The sensor consists of two Wheatstone bridges on a single wafer. Besides VCC and GND, there are positive and negative connections for both bridges, +V1, -V1, +V2, and –V2.
Q: How does the KMXP series determine position?
A: When the chip is moved with respect to a pole magnet, two sinusoidal signals are produced. These sinusoidal signals can be used to determine the position.
Q: Can the sensor be used to determine the angle of rotation?
A: Yes, to determine the angle of rotation, the field direction would be uniform and the sensor would be rotated.
Q: How is the maximum air gap determined?
A: The maximum air gap and pole length are related. A shorter pole length and smaller air gap improve sensor accuracy.
Q: Does TE supply the magnetic pole strip for applications?
A: No, typically the end customer will source the pole strip from a 3rd party but TESS can help define the requirements and help recommend potential suppliers..
