This part is a kind of semiconductor called BF421.

Function of this product has PNP Silicon Transistors (High breakdown voltage Low collector-emitter saturation voltage).

Manufacturers : Siemens Semiconductor Group

Image and pinout :

Some of the text within the PDF file :

PNP Silicon Transistors With High Reverse Voltage High breakdown voltage q Low collector-emitter saturation voltage q Low capacitance q Complementary types: BF 420, BF 422 (NPN) q 2 3 1 BF 421 BF 423 Type BF 421 BF 423 Marking – Ordering Code Q62702-F532 Q62702-F496 Pin Configuration 1 2 3 E C B Package1) TO-92 Maximum Ratings Parameter Collector-emitter voltage Collector-emitter voltage RBE = 2.7 k Collector-base voltage Emitter-base voltage Collector current Peak base current Junction temperature Storage temperature range Thermal Resistance Junction - ambient Junction - case2) Rth JA Rth JC ≤ ≤ Symbol VCE0 VCER VCB0 VEB0 IC IBM Tj Tstg Values BF 421 – 300 300 Unit BF 423 250 – 250 5 50 100 830 150 – 65 … + 150 mW ˚C mA V Total power dissipation, TC = 88 ˚C Ptot [ ... ]

BF421 PDF Datasheet Download