This part is a kind of semiconductor called FR9887.

Function of this product has 340KHz Synchronous Step-Down DC/DC Converter.

Manufacturers : Fiti

Image and pinout :

Some of the text within the PDF file :

FR9887 23V, 2A, 340KHz Synchronous Step-Down DC/DC Converter FEATURES High Efficiency up to 95% Low Rds(on) Integrated Power MOSFET Internal Compensation Function Wide Input Voltage Range: 4.5V to 23V Adjustable Output Voltage Down to 0.925V 2A Output Current Fixed 340KHz Switching Frequency External Programmable Soft-Start or Internal 600µs Soft-Start PSM (High Efficiency at Light Load) Power Good Indicator Output for Different Circuit Hiccup Short Circuit Protect TYPICAL APPLICATION CIRCUIT NAME BST VIN LX GND FB PG SHDN SS PIN DESCRIPTION SOP8 DESCRIPTION 1 High Side Gate Drive Boost 2 Power Supply Input Pin 3 Power Switching Output 4,9 Ground 5 Voltage Feedback Input 6 Power Good Output 7 Enable Input 8 Soft-Start TYPICAL APPLICATION STB (Set-Top-Box) LCD Display, TV Dist [ ... ]

FR9887 PDF Datasheet Download