3D Omnipolar Magnetic Sensor IC using Vertical Hall TechnologyMay 27, 2015 by Jeff Shepard
Allegro MicroSystems, LLC announces the A1266, a unique sensor IC incorporating a combination of vertical and traditional planar Hall-effect sensor ICs that can detect a magnetic field of either polarity in any direction. Its omnipolar, omnidirectional sensitivity makes it well-suited for detecting magnetic tampering in smart meters, ATMs, gambling/gaming machines, ticket machines, and electronic locks. The A1266 can also serve as a general-purpose magnetic switch that is relatively insensitive to magnet orientation or polarity in applications such as games, consumer electronics, white goods, etc.
This tiny surface-mount SOT23 IC is functionally equivalent to an array of three standard hall sensors mounted in three different orientations, something that is not possible with a single circuit board and all surface-mount components. The device has higher sensitivity than most conventional Hall-effect switches (BOP = 25 G typical). The result is high-sensitivity 3D tamper or proximity sensing in less space with lower assembly cost.
Each device integrates on a single silicon chip a Hall-voltage generator, a small-signal amplifier, chopper stabilization, a Schmitt trigger, and one or more NMOS outputs. Due to Allegroâ€™s proprietary dynamic offset cancellation techniques, the magnetic operating characteristics are specified across the operating voltage and temperature ranges. The A1266 is designed for operation in green and battery-powered systems; it can be powered from a 2.5 to 5.0 V supply and the average supply current is typically 7.5 ÂµA at 2.5 V. The operating temperature range is -40 to +85 degrees C.
Two configurations are available: one with a separate output for each sensing direction (X, Y, Z) and one with a combined output (X+Y+Z). Package type LH is a modified SOT23W surface mount package that is RoHS-compliant and lead (Pb) free (suffix, -T), with a 100% matte-tin plated leadframe. The pricing in quantities of 1,000 is: A1266ELHLT-T (X, Y, and Z outputs), $0.41; A1266ELHLT-T (single X+Y+Z output), $0.41.