This part is a kind of semiconductor called BCX42.

Function of this product has PNP Silicon AF and Switching Transistors (For general AF applications High breakdown voltage).

Manufacturers : Siemens Semiconductor Group

Image and pinout :

Some of the text within the PDF file :

PNP Silicon AF and Switching Transistors For general AF applications q High breakdown voltage q Low collector-emitter saturation voltage q Complementary types: BCX 41, BSS 64 (NPN) q BCX 42 BSS 63 Type BCX 42 BSS 63 Marking DKs BMs Ordering Code (tape and reel) Q62702-C1485 Q62702-S534 Pin Configuration 1 2 3 B E C Package1) SOT-23 Maximum Ratings Parameter Collector-emitter voltage Collector-base voltage Emitter-base voltage Collector current Peak collector current Base current Peak base current Total power dissipation, TS = 79 ˚C Junction temperature Storage temperature range Thermal Resistance Junction - ambient 2) Junction - soldering point Rth JA Rth JS ≤ ≤ Symbol VCE0 VCB0 VEB0 IC ICM IB IBM Ptot Tj Tstg 100 110 5 Values BSS 63 BCX 42 125 125 5 800 1 100 200 330 150 �� [ ... ]

BCX42 PDF Datasheet Download