This part is a kind of semiconductor called BCW31.

Function of this product has Surface mount Si-Epitaxial PlanarTransistors.

Manufacturers : Diotec Semiconductor

Image and pinout :

Some of the text within the PDF file :

BCW 31, BCW 32, BCW 33 NPN General Purpose Transistors NPN Surface mount Si-Epitaxial PlanarTransistors Si-Epitaxial PlanarTransistoren für die Oberflächenmontage Power dissipation – Verlustleistung 2.9 ±0.1 0.4 3 250 mW SOT-23 (TO-236) 0.01 g 1.1 Plastic case Kunststoffgehäuse 1.3 ±0.1 Type Code 1 2 2.5 max Weight approx. – Gewicht ca. Plastic material has UL classification 94V-0 Gehäusematerial UL94V-0 klassifiziert Standard packaging taped and reeled Standard Lieferform gegurtet auf Rolle 1.9 Dimensions / Maße in mm 1=B 2=E 3=C Maximum ratings (TA = 25/C) Collector-Emitter-voltage Collector-Base-voltage Emitter-Base-voltage Power dissipation – Verlustleistung Collector current – Kollektorstrom (DC) Peak Collector current – Kollektor-Spitzenstrom Peak Base cur [ ... ]

BCW31 PDF Datasheet Download