This part is a kind of semiconductor called BAS21N3.

Function of this product has High voltage switching diode.

Manufacturers : CYStech Electronics

Image and pinout :

Some of the text within the PDF file :

CYStech Electronics Corp. High voltage switching diode Spec. No. : C355N3-A Issued Date : 2004.04.13 Revised Date Page No. : 1/4 BAS21N3 Description The BAS21N3 is a general purpose diode fabricated in planar technology and encapsulated in a small SOT-23 plastic SMD package. Features •Fast switching speed : max. 50ns •Small plastic SMD package •General application. •Continuous reverse voltage : max. 200V •Repetitive peak reverse voltage : max. 250V •Repetitive peak forward current : max. 625mA Applications •General purpose switching in e.g. surface mounted circuits. Symbol Outline BAS21N3 2 3 1：Anode 2：Not Connected 3：Cathode 1 SOT-23 Cathode Not Connected Anode BAS21N3 CYStek Product Specification http:// CYStech Electronics Corp. Absolut [ ... ]

BAS21N3 PDF Datasheet Download