This part is a kind of semiconductor called B1431.

Function of this product has PNP Silicon Epitaxial Transistor.

Manufacturers : NEC

Image and pinout :

Some of the text within the PDF file :

'$7$ 6+((7 6,/,&21 32:(5 75$16,6725 6% 313 6,/,&21 (3,7$;,$/ 75$16,6725 '$5/,1*721 &211(&7,21 )25 /2:)5(48(1&< 32:(5 $03/,),(56 $1' /2:63((' 6:,7&+,1* The 2SB1431 is a Darlington power transistor that can directly drive from the IC output. This transistor is ideal for motor drivers and solenoid drivers in such as OA and FA equipment. In addition, a small resin-molded insulation type package contributes to high-density mounting and reduction of mounting cost. PACKAGE DRAWING (UNIT: mm) FEATURES • High hFE due to Darlington connection: hFE ≥ 2,000 (VCE = −2 V, IC = −3 A) • Mold package that does not require an insulating board or insulation bushing QUALITY GRADES • Standard Please refer to “Quality Grades on NEC Semiconductor Devices” (Document No. C11531E) pu [ ... ]

B1431 PDF Datasheet Download