This part is a kind of semiconductor called FP6321A.

Function of this product has Sunchronous Buck PWM DC-DC Controller.

Manufacturers : Fiti

Image and pinout :

Some of the text within the PDF file :

fitipower integrated technology lnc. FP6321A Synchronous Buck PWM DC-DC Controller Description The FP6321A is designed to drive two N-channel MOSFETs in a synchronous rectified buck topology. It provides the output adjustment, internal soft-start, frequency compensation networks, monitoring and protection functions into a single package. The IC operating at fixed 300kHz frequency provides simple, single feedback loop, voltage mode control with fast transient response. The resulting PWM duty ratio ranges from 0-100%. The FP6321A features over current protection. The output current is monitored by sensing the voltage drop across the RDS (ON) of the low side MOSFET which eliminates the need for a current sensing resistor. This device is available in SOP-8 package. Pin Assignment SO Package [ ... ]

FP6321A PDF Datasheet Download