This part is a kind of semiconductor called B1203.

Function of this product has 2SB1203.

Manufacturers : Sanyo Semiconductor

Image and pinout :

Some of the text within the PDF file :

Ordering number:EN2085B PNP/NPN Epitaxial Planar Silicon Transistors 2SB1203/2SD1803 High-Current Switching Applications Applications · Relay drivers, high-speed inverters, converters, and other general high-current switching applications. Features · Low collector-to-emitter saturation voltage. · High current and high fT. · Excellent linearity of hFE. · Fast switching speed. · Small and slim package making it easy to make 2SB1203/2SD1803-applied sets smaller. Package Dimensions unit:mm 2045B [2SB1203/2SD1803] unit:mm 2044B 1 : Base 2 : Collector 3 : Emitter 4 : Collector SANYO : TP [2SB1203/2SD1803] 1 : Base 2 : Collector 3 : Emitter 4 : Collector SANYO : TP-FA Any and all SANYO products described or contained herein do not have specifications that can handle applications that [ ... ]

B1203 PDF Datasheet Download