This part is a kind of semiconductor called A1121.

Function of this product has (A1120 - A1125) Chopper Stabilized Precision Hall Effect Switches.

Manufacturers : Allegro

Image and pinout :

Some of the text within the PDF file :

A1120, A1121, A1122, and A1125 Chopper Stabilized Precision Hall Effect Switches Features and Benefits ▪ ▪ ▪ ▪ ▪ ▪ ▪ ▪ Unipolar switchpoints Resistant to physical stress Superior temperature stability Output short-circuit protection Operation from unregulated supply Reverse battery protection Solid-state reliability Small package sizes Description The A1120, A1121, A1122, and A1125 Hall-effect, unipolar switches are extremely temperature-stable and stress-resistant sensor ICs, especially suited for operation over extended temperature ranges to 150°C. Superior high-temperature performance is made possible through dynamic offset cancellation, which reduces the residual offset voltage normally caused by device overmolding, temperature dependencies, and thermal stress. Each [ ... ]

A1121 PDF Datasheet Download