This part is a kind of semiconductor called BC558A.

Function of this product has (BC556 - BC558) PNP General Purpose Transistor.

Manufacturers : Weitron Technology

Image and pinout :

Some of the text within the PDF file :

BC556, A / B BC557, A / B / C BC558, A / B / C PNP General Purpose Transistor 2 BASE COLLECTOR 3 TO-92 1 1 EMITTER 2 3 Maximum Ratings ( TA=25 C unless otherwise noted) Rating Collector-Emitter Voltage Collector-Base Voltage Emitter-Base Voltage Collector Current Continuous Symbol VECO V CBO VEBO lC BC556 -65 -80 -5 BC557 -45 -50 -5 100 BC558 -30 -30 -5 Unit Vdc Vdc Vdc mAdc THERMAL CHARACTERISTICS Characteristics Total Device Dissipation Alumina Substrate, TA = 25 C BC556 BC557 BC558 BC556 BC557 BC558 Symbol PD Max 625 Unit mW/ C Junction and Storage, Temperature TJ, Tstg -55 to +150 C ELECTRICAL CHARACTERISTICS Characteristics Symbol Min Max Unit OFF CHARACTERISTICS Collector-Emitter Breakdown Voltage (lC = 2 mAdc. lB =0) Collector-Base Breakdown Vol [ ... ]

BC558A PDF Datasheet Download