This part is a kind of semiconductor called PAM8610.
Function of this product has 10W STEREO CLASS-D AUDIO POWER AMPLIFIER.
Manufacturers : Diodes
Image and pinout :

Some of the text within the PDF file :
A Product Line of Diodes Incorporated PAM8610 10W STEREO CLASS-D AUDIO POWER AMPLIFIER WITH DC VOLUME CONTROL Description The PAM8610 is a 10W (per channel) stereo Class-D audio amplifier with DC Volume Control which offers low THD+N (0.1%), low EMI, and good PSRR thus high-quality sound reproduction. The 32 steps DC volume control has a +32dB to -75dB range. Pin Assignments The PAM8610 runs off of a 7V to 15V supply at much higher efficiency than competitors’ ICs. The PAM8610 only requires very few external components, significantly saving cost and board space. The PAM8610 is available in a 40pin QFN 6mm*6mm package. Features 10W @ 10%THD/Channel Output into a 8Ω Load at 13V Low Noise: -90dB Over 90% Efficiency 32 Step DC Volume Control from -75dB to +32dB Wit [ ... ]
PAM8610 PDF Datasheet Download
