This part is a kind of semiconductor called LM7803SR.

Function of this product has High-Efficiency Switching Regulators.

Manufacturers : Datel

Image and pinout :

Some of the text within the PDF file :

www.DataSheet.co.kr ® ® A SUBSIDIARY OF C&D TECHNOLOGIES 78SR Series NEW low-profile package Order online at www.datel.com Features • 3.3V/0.5A, 5V/0.5A or 12V/0.4A outputs; Pin and size-compatible with LM7805 & LM7812 regulators • Up to 95% efficiency – no heat sinks or thermal derating required! • Two SIP-packages fit existing TO-220 footprints: Vertical-pin models occupy less than 0.1 square in. Optional horizontal pins provide 0.350 in. installed height • +7.5-36Vdc operating input range; Low 3mA quiescent current • Built-in filter capacitors – no external components required • –40 to +70°C operation at full load; Short-circuit protection • Excellent load (±0.2%) and line (±0.3%) regulation • Ideal for powering instrumentation from 9V/12V/24V/28V sup [ ... ]

LM7803SR PDF Datasheet Download