This part is a kind of semiconductor called BD9876AEFJ.

Function of this product has Flexible Step-down Switching Regulators.

Manufacturers : Rohm

Image and pinout :

Some of the text within the PDF file :

Datasheet Single-chip Type with Built-in FET Switching Regulators Flexible Step-down Switching Regulators with Built-in Power MOSFET BD9876AEFJ ●General Description Output 3.0A and belo w High Efficiency Rate Step-down Switching Re gulator Po wer MOSF ET Internal Type BD9876AEFJ mainl y used as second ary s ide Po wer supply, for example from fixed Power supply of 12V, 24V etc, Step-down Output of 1.2V/1.8V/3.3V/5V, etc, can be produced. T his IC h as e xternal C oil/Capacitor down-sizing throu gh 30 0kHz F requency operation, inside Nch-F ET SW for 45V “ withstand-pressure” commutation and als o, hig h speed l oad respons e through Curr ent Mode Control is a s imple e xternal setting ph ase compensati on sy stem, through a wide range e xternal const ant, a c ompact Po wer suppl y c [ ... ]

BD9876AEFJ PDF Datasheet Download