Smart TMR Magnetometer for industrial applications

TMR Magnetometer is a fast and accurate sensor, ideal for proximity or non-contact current detection

NVE Corporation’s SM225-10E high-speed Tunneling Magnetoresistance (TMR) Smart Magnetometer is part of a family of transformative sensors defining the new state-of-the-art for magnetic sensing technology. TMR technology offers higher accuracy, higher sensitivity, better temperature stability, lower power consumption, and smaller package sizes compared to Hall effect sensors. Higher-performance TMR sensors like the SM225-10E are ideal for the Industrial Internet of Things revolution, which demands better sensors, better connectivity, and better prices.

The SM225-10E combines a unique TMR sensor element with elegant digital signal processing in an ultraminiature DFN package. A high-speed Serial Peripheral Interface (SPI) interface provides access to sensor data and programmable parameters.

The SM225-10E is a general-purpose, programmable magnetometer with high sensitivity and high accuracy. The TMR sensor elements are sensitive in-plane, which is optimal for non-contact current sensing and off-axis mechanical magnet configurations.

SM225-10E parts are used with either ferrite or rare-earth permanent magnets and can detect over 60 millimeters of linear travel.

The sensor can also stand as a non-contact current sensor with unlimited isolation. Typical current ranges are ±250A up to ±1000A.

The sensor can be used for linear sensing or as a switch with programmable open-and-close thresholds.

In short, the SM225 is the most accurate high-speed magnetometer in its class. With a total accuracy specification of two percent of full-scale over a 0 to 125 degree Celsius operating temperature range, and four percent over the full minus 40 to 125 degree Celsius operating range. Accuracy is specified as a percentage of the SM225’s full-scale range of 15 millitesla (150 oersteds). The accuracy specification covers all error sources, including sensitivity, offset, nonlinearity, hysteresis, noise, and supply variation.

Top features

Following is the summary of Key SM225-10E features:

  •  Wide 0 to 150 Oe / 0 to 15 mT linear range
  • Can detect ordinary magnets more than 50 mm away
  • Fast SPI interface
  •  2% of full-scale accuracy for 0 to 125°C
  • Fast 15000 samples per second update rate
  • Factory calibrated
  • Programmable offset and gain compensation
  •  -40°C to 125°C operating range
  • Ultraminiature 2.5 x 2.5 mm TDFN package
Evaluation Kit

The AG953H-07E Evaluation Kit has everything needed to evaluate the SM225-10E. The Kit includes an evaluation board with an SM225-10E sensor and a microcontroller with a USB interface, evaluation software, a permanent magnet, and a current-carrying busbar with screw connections.

NVE is a leader in the practical commercialization of spintronics, a nanotechnology that relies on electron spin rather than electron charge to acquire, store and transmit information. The company manufactures high-performance spintronic products including sensors and couplers that are capable to acquire and transmit data. NVE has also licensed its spintronic magnetoresistive random access memory technology, commonly known as MRAM.

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