This part is a kind of semiconductor called LSP5523.

Function of this product has 3A 27V Synchronous Buck Converter.

Manufacturers : Lite-On

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LSP5523 3A 27V Synchronous Buck Converter General Description The LSP5523 is a monolithic synchronous buck regulator. The device integrates 90 mΩ MOSFETS that provide 3A continuous load current over a wide operating input voltage of 4.5V to 27V. Current mode control provides fast transient response and cycle-by-cycle current limit. An adjustable soft-start prevents inrush current at turn on. Features  3A Output Current  Wide 4.5V to 27V Operating Input Range  Fixed 340KHZ Frequency  Integrated Power MOSFET Switches  Output Adjustable from 0.925V to 0.8Vin  Up to 93% Efficiency  Programmable Soft-Start  Stable with Low ESR Ceramic Output Capacitors  Cycle by Cycle Over Current Protection  Short Circuit Protection  Input Under Voltage Lockout  Package�� [ ... ]

LSP5523 PDF Datasheet Download