NVE SM225-10E TMR smart magnetometer

NVE Corporation has launched the SM225-10E high-speed TMR smart magnetometer, which is suitable for measuring proximity or AC current. The sensor combines a tunnelling magnetoresistance (TMR) sensor element with elegant digital signal processing. An SPI interface provides access to sensor data and programmable parameters.

Unlike old-fashioned Hall-effect sensor elements, the smart magnetometer uses GMR and TMR, which are sensitive in-plane for optimal current sensing and easy mechanical interfaces. It has a magnetic bandwidth of 7.5 kHz and a fast update speed of 15,000 samples per second, making it useful for noncontact AC current sensing. It comes in a leadless TDFN package measuring 2.5 x 2.5 x 0.8 mm.

The magnetometer has a total accuracy specification of ±2% of full-scale over 0 to 125°C and ±4% over the full -40 to 125°C operating range. Accuracy is specified as a percentage of the full-scale range of 150 Oe or 15 mT. The accuracy specification covers all error sources, including sensitivity, offset, nonlinearity, hysteresis, noise and supply variation.

The AG953-07 Evaluation Kit is also available, offering 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; a current-carrying trace under the sensor for evaluating as a current sensor; a small ceramic magnet for evaluating as a proximity sensor; a PWM output for tracking the field with a voltmeter; and a powerful, intuitive graphical user interface.