This part is a kind of semiconductor called 278R33.

Function of this product has 4 TERMINAL 2A OUTPUT LOW DROP VOLTAGE REGULATOR.

Manufacturers : UTC

Image and pinout :

Some of the text within the PDF file :

UNISONIC TECHNOLOGIES CO., LTD 278RXX 4 TERMINAL 2A OUTPUT LOW DROP VOLTAGE REGULATOR „ DESCRIPTION 1 TO-220F-4 LINEAR INTEGRATED CIRCUIT The UT C 278RXX Seri es ar e Lo w Drop V oltage Re gulator suitable for various electronic equipments. It provides constant voltage power source with TO-220F-4 terminal lead full molded PKG. The Regulator has multi function such as over current protection, overheat protection and ON/OFF control. „ FEATURES * 2.0A Output Low Drop Voltage Regulator. * Built in ON/OFF Control Terminal. * Built in Over Current Protection, Over Heat Protection Function. „ ORDERING INFORMATION Ordering Number Lead Free Halogen Free 278RXXL-TF4-T 278RXXG-TF4-T xx: Output Voltage, refer to Marking Information. Package TO-220F-4 Packing Tube Note: www.unisonic.com.tw [ ... ]

278R33 PDF Datasheet Download