By Allegro MicroSystems, LLC 13
Allegro's A119x family of two-wire, unipolar, Hall effect switches can be trimmed by the user at end-of-line to optimize magnetic switchpoint accuracy in the application. These devices are produced on the Allegro advanced BiCMOS wafer fabrication process, which implements a patented high frequency, 4-phase, chopper-stabilization technique. This technique achieves magnetic stability over the full operating temperature range, and eliminates offsets inherent in devices with a single Hall element that are exposed to harsh application environments.
The A119x family has a number of automotive applications. These include sensing seat track position, seat belt buckle presence, hood/trunk latching, and shift selector position.