This part is a kind of semiconductor called ft2820.

Function of this product has 4W Dual-Pump Class-G Audio Power Amplifier.

Manufacturers : Fangtek

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ft2820 4W Dual-PumpTM Class-G Audio Power Amplifier GENERAL DESCRIPTION The ft2820 is a 4W boosted Class-G audio power amplifier based upon a proprietary Dual-PumpTM topology with automatic level control (ALC). It operates from 3V to 5.5V supply. When operating with a 4.2V supply voltage, it is capable of driving a 4Ω speaker load at a continuous average output of 4W with 10% THD+N. Its high efficiency, up to 82%, helps extend battery life for portable device applications. In ft2820, the power supply rail for the amplifier’s output stage is internally boosted and regulated at 6V by an adaptive charge pump based upon the Dual-PumpTM topology, thus allowing for a much louder audio output than a stand-alone one directly connected to the battery. It makes ft2820 an ideal audio solution for [ ... ]

ft2820 PDF Datasheet Download