This part is a kind of semiconductor called AS1002.

Function of this product has PWM Buck Converter.

Manufacturers : Anisem

Image and pinout :

Some of the text within the PDF file :

AS1002 FEATURES Precision feedback reference voltage: 0.5V (2%) Wide supply voltage operating range: 3.0 to 20V Low current consumption: 5.5mA Internal fixed oscillator frequency: Typ. 350KHz Programmable Soft-Start function (SS) Short Circuit Shutdown and Auto Re-start function(ARSCP) Built-in P-MOSFET for 2A loading capability Package: SOP8 350KHz, 2A PWM Buck Converter GENERAL DESCRIPTION The AS1002 is a buck topology of switching regulator for wide operating voltage applications field. The AS1002 includes a high current P-MOSFET, high precision reference (0.5V) for comparing output voltage with feedback amplifier, an internal dead-time control and oscillator for controlling the maximum duty cycle and PWM frequency, and has power-on programmable soft start time and short circuit PMOS [ ... ]

AS1002 PDF Datasheet Download