This part is a kind of semiconductor called S8550.

Function of this product has Silicon Epitaxial Planar Transistor.

Manufacturers : BL

Image and pinout :

Some of the text within the PDF file :

BL Galaxy Electrical Silicon Epitaxial Planar Transistor FEATURES z z z High Collector Current.(IC= -500mA） Complementary To S8050. Excellent HFE Linearity. Production specification S8550 Pb Lead-free APPLICATIONS z High Collector Current. SOT-23 ORDERING INFORMATION Type No. S8550 Marking 2TY Package Code SOT-23 MAXIMUM RATING @ Ta=25℃ unless otherwise specified Symbol VCBO VCEO VEBO IC PC Tj,Tstg Parameter Collector-Base Voltage Collector-Emitter Voltage Emitter-Base Voltage Collector Current -Continuous Collector Dissipation Junction and Storage Temperature Value -40 -25 -5 -500 300 -55~150 Units V V V mA mW ℃ Document number: BL/SSSTC080 Rev.A www.galaxycn.com 1 BL Galaxy Electrical Silicon Epitaxial Planar Transistor ELECTRICAL CHARACTERISTICS @ Ta [ ... ]

S8550 PDF Datasheet Download