Hall-IC offers precise omnipolar/unipolar detection

March 06, 2012 // By Paul Buckley
Seiko Instruments Inc. has developed its S-5716 Hall-IC Series in CMOS technology to provide precise magnetic sensors using the Hall-effect to detect omnipolar N- and S-pole or unipolar either N- or S-pole magnetic flux.

The detection of magnetic flux reverses the polarity of the Hall-ICs output voltage. The typical magnetic sensitivity is available in steps of 1.8 mT; 3.0 mT and 4.5 mT. The S-5716 Series detects magnetic flux perpendicular to the printed surface of the Hall-IC. With the omnipolar-version a change of the output state is initiated by approximation of either a magnetic N- or S-pole to the marked surface. The unipolar versions will change their output when a magnetic flux matching the polarity sensitivity of the Hall sensor approaches the marked surface of the IC. The approach with the other polarity will not have any effect.     

The low current requirement is typical 4.0 µA with the omnipolar Version and 2.6 µA with the unipolar Version at an average sampling rate of 20 Hz. Typical cycle time is 50.5 ms with 0.1 ms awake time for the omnipolar-version and 50.85 ms with 0.05 ms awake time for the unipolar version.     

The supply range 2.7 V to 5.5 V permits various implementations which enable open/closed detections using a single magnet in a multitude of applications. The omnipolar-version would even support distinction of an opening direction. The application range is electronic equipment for entertainment, communication devices and home and office appliance.    

The S-5716 Hall-IC Series is available in manufacturing quantities.