This part is a kind of semiconductor called AS2880.

Function of this product has 8A Low Dropout Voltage Regulator Adjustable & Fixed 3.3V.

Manufacturers : Sipex Corporation

Image and pinout :

Some of the text within the PDF file :

FEATURES • Adjustable Output Down to 1.2V or Fixed 3.3 V & 5 V • Output Current of 8A • Low Dropout Voltage • Extremely Tight Load and Line Regulation • Current & Thermal Limiting • Standard 3-Terminal Low Cost TO-220 • Similar to Industry Standard LT1083/LT1584 AS2880 8A Low Dropout Voltage Regulator Adjustable & Fixed 3.3V APPLICATIONS • Powering Intel Pentium™ | P from +5V Supplies • Power PC™ Supplies • SMPS Post-Regulator • High Efficiency "Green" Computer Systems • High Efficiency Linear Power Supplies • Portable Instrumentation • Constant Current Regulators • Adjustable Power Supplies • Battery Charger PRODUCT DESCRIPTION The AS2880 is a low power 8A Adjustable Voltage Regulator that is very easy to use. It requires only 2 external resistors to [ ... ]

AS2880 PDF Datasheet Download