This part is a kind of semiconductor called MT3420.

Function of this product has 2A Synchronous Step-Down Converter.

Manufacturers : Aerosemi Technology

Image and pinout :

Some of the text within the PDF file :

MT3420 Rev.V1.2 1.4MHz, 2A Synchronous Step-Down Converter FEATURES • High Efficiency: Up to 96% • 1.4MHz Constant Frequency Operation • 2A Output Current • No Schottky Diode Required • 2.5V to 5.5V Input Voltage Range • Output Voltage as Low as 0.6V • PFM Mode for High Efficiency in Light Load • 100% Duty Cycle in Dropout Operation • Low Quiescent Current: 40µA • Slope Compensated Current Mode Control for Excellent Line and Load Transient Response • Short Circuit Protection • Thermal Fault Protection • Inrush Current Limit and Soft Start • <1µA Shutdown Current • TDFN33-10 package APPLICATIONS • Cellular and Smart Phones • Wireless and DSL Modems • PDAs • Portable Instruments • Digital Still and Video Cameras • PC Cards GENERAL DESCRIPTION The [ ... ]

MT3420 PDF Datasheet Download