This part is a kind of semiconductor called BCX41.

Function of this product has NPN Silicon AF and Switching Transistors.

Manufacturers : Infineon Technologies AG

Image and pinout :

Some of the text within the PDF file :

BCX41, BSS64 NPN Silicon AF and Switching Transistors
For general AF applications
High breakdown voltage
Low collector-emitter saturation voltage
Complementary types: BCX42, BSS63 (PNP) 3 2 1 VPS05161 Type BCX41 BSS64 Maximum Ratings Parameter Marking EKs AMs 1=B 1=B Pin Configuration 2=E 2=E 3=C 3=C Package SOT23 SOT23 Symbol VCEO VCBO VEBO BSS64 80 120 5 800 1 100 200 330 150 BCX41 125 125 5 Unit V Collector-emitter voltage Collector-base voltage Emitter-base voltage DC collector current Peak collector current Base current Peak base current Total power dissipation, TS = 79 °C Junction temperature Storage temperature IC ICM IB IBM Ptot Tj Tstg mA A mA mW °C -65 ... 150 Thermal Resistance Junction - soldering point 1) RthJS
215 K/W 1For calculation of R thJA p [ ... ]

BCX41 PDF Datasheet Download