This part is a kind of semiconductor called LSP3120.

Function of this product has 3A PWM Buck DC-DC Converter.

Manufacturers : Lite-On

Image and pinout :

Some of the text within the PDF file :

Liteon Semiconductor Corporation LSP3120 52KHZ 3A PWM Buck DC/DC Converter FEATURES Output voltage: 3.3V, 5.0V, 12V, and adjustable output version Adjustable version output voltage range:1.23V to 37V±4% 52KHz±15% fixed switching frequency Voltage mode non-synchronous PWM control Thermal-shutdown and current-limit protection ON/OFF shutdown control input Operating voltage can be up to 40V Output load current: 3A Low power standby mode Built-in switching transistor on chip TO220-5L,TO263-5L packages GENERAL DESCRIPTION The LSP3120 series are monolithic IC that design for a step-down DC/DC converter, and own the ability of driving a 3A load without additional transistor component. Due to reducing the number of external component, the board space can be saved easily. The external shutdown f [ ... ]

LSP3120 PDF Datasheet Download