This part is a kind of semiconductor called AX3482.

Function of this product has 340kHz Synchronous Rectified Step-Down Converter.

Manufacturers : AXElite

Image and pinout :

Some of the text within the PDF file :

AX3482 2A, 23V, 340kHz Synchronous Rectified Step-Down Converter  GENERAL DESCRIPTION The AX3482 is a monolithic synchronous buck regulator. The device integrates two 130mΩ MOSFETs, and provides 2A of continuous load current over a wide input voltage of 4.75V to 23V. Current mode control provides fast transient response and cycle-by-Cycle current limit. An adjustable soft-start prevents inrush current at turn-on, and in shutdown mode the supply current drops to 1μA. This device, available in an 8-pin SOP package, provides a very compact solution with minimal external components.  FEATURES 2A Output Current Wide 4.75V to 23V Operating Input Range Integrated 130mΩ Power MOSFET Switches Output adjust from VFB to 20V Up to 93% Efficiency Programmable Soft-Start Stable with Low ESR Cer [ ... ]

AX3482 PDF Datasheet Download