This part is a kind of semiconductor called BC556.

Function of this product has PNP general purpose transistors.

Manufacturers : NXP

Image and pinout :

Some of the text within the PDF file :

DISCRETE SEMICONDUCTORS DATA SHEET dbook, halfpage M3D186 BC556; BC557 PNP general purpose transistors Product data sheet Supersedes data of 1999 Apr 15 2004 Oct 11 NXP Semiconductors PNP general purpose transistors Product data sheet BC556; BC557 FEATURES • Low current (max. 100 mA) • Low voltage (max. 65 V). APPLICATIONS • General purpose switching and amplification. DESCRIPTION PNP transistor in a TO-92; SOT54 plastic package. NPN complements: BC546 and BC547. PINNING PIN 1 2 3 emitter base collector DESCRIPTION handbook, halfpage1 2 3 2 MAM281 3 1 Fig.1 Simplified outline (TO-92; SOT54) and symbol. ORDERING INFORMATION TYPE NUMBER BC556 BC557 NAME SC-43A PACKAGE DESCRIPTION plastic single-ended leaded (through hole) package; 3 leads VERSION SOT54 LIMITING VALUE [ ... ]

BC556 PDF Datasheet Download