This part is a kind of semiconductor called BC517.

Function of this product has Darlington Transistors(NPN Silicon).

Manufacturers : ON Semiconductor

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Some of the text within the PDF file :

BC517 Darlington Transistors NPN Silicon Features • Pb−Free Packages are Available* MAXIMUM RATINGS Rating Collector −Emitter Voltage Collector −Base Voltage Collector −Emitter Voltage Collector Current − Continuous Total Power Dissipation @ TA = 25°C Derate above TA = 25°C Total Power Dissipation @ TA = 25°C Derate above TA = 25°C Operating and Storage Junction Temperature Range Symbol VCES VCB VEB IC PD PD TJ, Tstg Value 30 40 10 1.0 625 12 1.5 12 −55 to +150 Unit Vdc Vdc Vdc Adc mW mW/°C W mW/°C °C 12 3 http://onsemi.com COLLECTOR 1 BASE 2 EMITTER 3 TO−92 CASE 29 STYLE 17 THERMAL CHARACTERISTICS Characteristic Thermal Resistance, Junction−to−Ambient Thermal Resistance, Junction−to−Case Symbol RqJA RqJC Max 200 83.3 Unit °C/W °C/ [ ... ]

BC517 PDF Datasheet Download