This part is a kind of semiconductor called A92.

Function of this product has NPN Silicon Epitaxial Planar Transistor.

Manufacturers : WEJ

Image and pinout :

Some of the text within the PDF file :

  A92 NPN Silicon Epitaxial Planar Transistor FEATURES z Collector-Emitter voltage:VCEO=300V. z Collector current up to 500mA. z Complement to A92. z Small flat package. z Power dissipation:Pd(max)=500mW. Pb Lead-free  APPLICATIONS z High voltage transistor. ORDERING INFORMATION Type No. Marking A42 A42 SOT-89 Package Code SOT-89 MAXIMUM RATING @ Ta=25℃ unless otherwise specified Symbol Parameter VCBO collector-base voltage VCEO collector-emitter voltage VEBO emitter-base voltage IC collector current (DC) PC Tj ,Tstg Collector dissipation junction and storage temperature Value 310 305 5 0.5 0.5 -55-150 UNIT V V V A W °C  WEJ ELECTRONIC CO./7' Http:// www.wej.cn E-mail:wej@yonge rjia.com A42 ELECTRICAL CHARACTERISTICS @ Ta=25℃ unless otherwise spec [ ... ]

A92 PDF Datasheet Download