The A115x family, comprising the A1152, A1153, A1156, and A1157 devices, are factory-trimmed to optimise magnetic switchpoint accuracy. The different devices are distinguished by the choice of magnetic switch-points, output current, output polarity, and package.
These devices are produced using the Allegro advanced BiCMOS wafer fabrication process, which uses a patented high-frequency 4-phase chopper-stabilisation 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 A115x sensors were developed for use in automotive and industrial applications that are safety-critical or involve long sensor wiring harnesses. Typical applications include seat track position sensing, seat-belt buckle presence, hood/trunk latching, and shift selector position sensing.
Two-wire switches are particularly advantageous in cost- and/or weight-sensitive applications because they require one less wire for operation than the more traditional open-collector output switches. In addition, the system offers diagnostic capabilities because there is always output current flowing in either of two narrow ranges. A current level not within these ranges indicates a fault condition.
Visit Allegro MicroSystems at www.allegromicro.com