This part is a kind of semiconductor called A1266.

Function of this product has Micropower Ultrasensitive 3D Hall-Effect Switch.

Manufacturers : Allegro

Image and pinout :

Some of the text within the PDF file :

A1266 Micropower Ultrasensitive 3D Hall-Effect Switch FEATURES AND BENEFITS • True 3D sensing • Omnipolar operation with either north or south pole • 2.5 to 5.5 V operation • Low supply current • High sensitivity, BOP typically 25 G • Chopper-stabilized offset cancellation □□Superior temperature stability □□Extremely low switchpoint drift □□Insensitive to physical stress • Solid-state reliability • Choice of output format □□Separate X, Y, and Z outputs □□Combined (X+Y+Z) output • Tiny SOT-23 packages PACKAGES: 5-Pin SOT23-W 3-Pin SOT23-W DESCRIPTION The A1266 integrated circuit is an ultrasensitive Hall-effect switch with 3D omnipolar magnetic actuation. The single silicon chip includes: three Hall plates, multiplexer, smallsignal amplif [ ... ]

A1266 PDF Datasheet Download