This part is a kind of semiconductor called SY8120B.

Function of this product has Synchronous Step Down Regulator.

Manufacturers : Silergy

Image and pinout :

Some of the text within the PDF file :

昱灿电子 www.szyucan.com Application Note: AN_SY8120B High Efficiency Fast Response, 2A, 18V Input Synchronous Step Down Regulator General Description SY8120B develops high efficiency synchronous stepdown DC-DC converter capable of delivering 2A load current . SY8120B operates over a wide input voltage range from 4.5V to 18V and integrates main switch and synchronous switch with very low RDS(ON) to minimize the conduction loss. SY8120B adopts the instant PWM architecture to achieve fast transient responses for high step down applications and high efficiency at light loads. In addition, it operates under heavy load conditions to minimize the size of inductor and capacitor. Ordering Information SY8120 ( ) Temperature Code Package Code Optional Spec Code Temperature Range: -40°C [ ... ]

SY8120B PDF Datasheet Download