Allegro MicroSystems Inc. Chopper-Stabilized Precision Hall-Effect Switch A1123LLHLT-T

The A1123LLHLT-T is a chopper-stabilized precision Hall-effect switch designed for automotive applications, featuring unipolar switching with a south pole magnetic field trigger. It operates from an unregulated supply voltage of 3 to 24 V and includes output short-circuit and reverse-battery protection. The device is AEC-Q100 qualified and supports ambient temperatures from -40°C to 150°C, with a maximum junction temperature of 165°C. It uses a 3-pin SOT23W surface-mount package (suffix LH) and provides a 25 mA open-drain output. The chopper-stabilized design ensures superior temperature stability and stress resistance. The part is surface-mount and comes in a 7-in. reel packaging configuration.