This part is a kind of semiconductor called BU2508DF.
Function of this product has Silicon Diffused Power Transistor.
Manufacturers : NXP
Image and pinout :

Some of the text within the PDF file :
Philips Semiconductors Product specification Silicon Diffused Power Transistor BU2508DF GENERAL DESCRIPTION Enhanced performance, new generation, high-voltage, high-speed switching npn transistor with an integrated damper diode in a plastic full-pack envelope intended for use in horizontal deflection circuits of colour television receivers. Features exceptional tolerance to base drive and collector current load variations resulting in a very low worst case dissipation. QUICK REFERENCE DATA SYMBOL VCESM VCEO IC ICM Ptot VCEsat ICsat VF tf PARAMETER Collector-emitter voltage peak value Collector-emitter voltage (open base) Collector current (DC) Collector current peak value Total power dissipation Collector-emitter saturation voltage Collector saturation current Diode forward voltage Fa [ ... ]
BU2508DF PDF Datasheet Download
