This part is a kind of semiconductor called AK4637.

Function of this product has 24bit Mono CODEC.

Manufacturers : AKM

Image and pinout :

Some of the text within the PDF file :

[AK4637] AK4637 24bit Mono CODEC with MIC/SPK-AMP 1. General Description The AK4637 is a low power 24-bit Mono CODEC with a microphone and speaker amplifiers. The AK4637 supports sampling frequency from 8kHz to 48kHz. It is suitable for a wide range of application from speech signal processing for narrowband, wideband and super wideband to sound signal processing for audio band. The input circuits include a microphone amplifier and a high performance digital ALC (automatic level control) circuit. In addition, the output circuits include a speaker amplifier with 1W output power. It is suitable for various products as well as portable applications with recording/playback function. The AK4637 are available in a small 20-pin QFN (3mm x 3mm, 0.4mm pitch: AK4637EN) package saving mounting area o [ ... ]

AK4637 PDF Datasheet Download