This part is a kind of semiconductor called SSF7509A.

Function of this product has MOSFET.

Manufacturers : Silikron Semiconductor

Image and pinout :

Some of the text within the PDF file :

Main Product Characteristics: VDSS 75V RDS(on) 6.5mohm(typ.) ID 80A Features and Benefits: D2PAK „ Advanced trench MOSFET process technology „ Special designed for PWM, load switching and general purpose applications „ Ultra low on-resistance with low gate charge „ Fast switching and reverse body recovery „ 175℃ operating temperature SSF7509A Marking and pin Assignment Schematic diagram Description: It utilizes the latest trench processing techniques to achieve the high cell density and reduces the on-resistance with high repetitive avalanche rating. These features combine to make this design an extremely efficient and reliable device for use in power switching application and a wid [ ... ]

SSF7509A PDF Datasheet Download