This part is a kind of semiconductor called APA2057A.

Function of this product has 2.4W Stereo Audio Power Amplifier.

Manufacturers : Anpec Electronics Coropration

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APA2057A 2.4W Stereo Audio Power Amplifier (with Gain Setting) & Capfree Headphone Driver Features General Description The APA2057A is a monolithic integrated circuit, which combines a stereo power amplifier and a stereo output capacitor-less headphone amplifier. The stereo power amplifier provides 19-steps gain setting for flexible application. The headphone amplifier is ground-reference output, and no need the output capacitors for DC blocking. The advantages of eliminating the output capacitor are saving the cost, PCB’ s space and component height. Both the de-pop circuitry and the thermal shutdown protection circuitry are integrated in the APA2057A, which reduces pops and clicks noise during power on/ off and in shutdown mode. Thermal shutdown protects the chip from being destroyed b [ ... ]

APA2057A PDF Datasheet Download