This part is a kind of semiconductor called B1243.

Function of this product has 2SB1243.

Manufacturers : Rohm

Image and pinout :

Some of the text within the PDF file :

Transistors Power Transistor (*60V, *3A) 2SB1184 / 2SB1243 / 2SB1185 FFeatures 1) Low VCE(sat). VCE(sat) = *0.5V (Typ.) (IC / IB = *2A / *0.2A) 2) Complements the 2SD1760 / 2SD1864 / 2SD1762. FStructure Epitaxial planar type PNP silicon transistor FExternal dimensions (Units: mm) (96-128-B57) 223 Transistors FAbsolute maximum ratings (Ta = 25_C) 2SB1184 / 2SB1243 / 2SB1185 FElectrical characteristics (Ta = 25_C) FPackaging specifications and hFE hFE values are classified as follows : 224 Transistors FElectrical characteristic curves 2SB1184 / 2SB1243 / 2SB1185 225 Transistors 2SB1184 / 2SB1243 / 2SB1185 226 [ ... ]

B1243 PDF Datasheet Download