This part is a kind of semiconductor called BU808DFX.
Function of this product has HIGH VOLTAGE FAST-SWITCHING NPN POWER DARLINGTON TRANSISTOR.
Manufacturers : STMicroelectronics
Image and pinout :

Some of the text within the PDF file :
BU808DFX HIGH VOLTAGE FAST-SWITCHING NPN POWER DARLINGTON TRANSISTOR s s s s s s s STMicroelectronics PREFERRED SALESTYPE NPN MONOLITHIC DARLINGTON WITH INTEGRATED FREE-WHEELING DIODE HIGH VOLTAGE CAPABILITY (> 1400 V) HIGH DC CURRENT GAIN (TYP. 150) FULLY INSULATED PACKAGE (U.L. COMPLIANT) FOR EASY MOUNTING LOW BASE-DRIVE REQUIREMENTS DEDICATED APPLICATION NOTE AN1184 1 3 2 s APPLICATIONS COST EFFECTIVE SOLUTION FOR HORIZONTAL DEFLECTION IN LOW END TV UP TO 21 INCHES. DESCRIPTION The BU808DFX is a NPN transistor in monolithic Darlington configuration. It is manufactured using Multiepitaxial Mesa technology for cost-effective high performance. ISOWATT218FX INTERNAL SCHEMATIC DIAGRAM ABSOLUTE MAXIMUM RATINGS Symbol V CBO V CEO V EBO IC I CM IB I BM P tot V iso [ ... ]
BU808DFX PDF Datasheet Download
