audio signal encoder circuit

After the MP3/MP4 machine receives the microphone signal or line input signal, it should be sent to the audio signal encoder for encoding. As
shown in the figure, the circuit diagram using the UIL WM8731 integrated encoder is used. The audio signal from the microphone is amplified by the amplifier and sent to the @ pin of the audio signal encoder Ull. The two-channel audio signal from the audio switching circuit is sent to the @ and @ pins of Ull. foot. UIL first performs switching processing on the input audio signal and then performs A/D conversion and digital encoding, converts the analog audio signal into a digital audio signal, and stores it in the memory under the control of the CPU to complete the storage of the audio signal .