This part is a kind of semiconductor called LSP5503.

Function of this product has 3A Synchronous Step Down DC/DC Converter.

Manufacturers : Liteon Semiconductor

Image and pinout :

Some of the text within the PDF file :

LSP5503 3A Synchronous Step Down DC/DC Converter „ FEATURES z 3A Output Current z Wide 4.5V to 27V Operating Input Range z Integrated 100m Power MOSFET Switches z Output Adjustable from 0.925V to 24V z Up to 96% Efficiency z Programmable Soft-Start z Stable with Low ESR Ceramic Output Capacitors z Fixed 400KHz Frequency z Cycle-by-Cycle Over Current Protection z Input Under Voltage Lockout z SOP8L-EP Package „ GENERAL DESCRIPTION The LSP5503 is a monolithic synchronous buck regulator. The device integrates 100mΩ MOSFETS that provide 3A continuous load cur-rent over a wide operating input voltage of 4.5V to 27V. Current mode control provides fast transient response and cycle-by-cycle cur-rent limit. An adjustable soft-start prevents inrush current at turn on. In shutdown mode, the suppl [ ... ]

LSP5503 PDF Datasheet Download