Allegro MicroSystems, Inc. Introduces a New Addition to Their Family of Switches and Latches
Improved Switching Repeatability in Multiple Package Options 
Worcester, MA – September 10, 2009 — Allegro® introduces a new addition to their family of Hall-effect switches and latches. The A1222 is an extremely temperature-stable and stress-resistant sensor IC suited for operation over extended temperature ranges to 150°C. Superior high temperature performance is made possible through dynamic offset cancellation, reducing the residual offset voltage normally caused by device over-molding, temperature dependencies, and thermal stress. Allegro’s new A1222 device is most commonly used to detect the speed and direction of ring magnets for motor commutation.
Allegro’s A1222 includes on a single silicon chip: a voltage regulator, Hall-voltage generator, small-signal amplifier, chopper stabilization, Schmitt trigger, and short-circuit protected open-collector output that can sink up to 25 mA. An on-board regulator permits operation with supply voltages of 3.0 to 24 V. Significant advantages are realized by reducing the minimum operating voltage. This device can be used in 3 V applications and additional external resistance can be added in series with the supply pin for greater protection against transient events.
Two package styles provide a magnetically optimized package for most applications. Package type LH is a modified SOT23W, surface mount package, while the UA is a three-lead, ultra-mini-SIP for through-hole mounting. Each package type is available as lead (Pb) free (suffix, -T), with a 100% matte tin-plated lead frame.
