Here is a very compact module with ADC & DAC I2S function .

The ADC stage operates using a CS5343 chip multi-bit A-Z modulator and an LME49721 operational amplifier (digital filter and high pass filter embedded).

It is suitable for all compact applications involving quality sound aquisition with its dynamic range of 98dB and its Signal / Noise ratio of -92dB.

ADC can be reached simply thanks tp a 3.5mm stereo jack connector which is already installed & soldered on the PCB. The only thing to do is it to connect a microphone and connect the I2S port on a standard I2S format read device to operate.

The DAC stage uses a 24-bit CS4344 chip with a maximum sampling rate of 192 kHz and high performanceoperational amplifier LA4811.

This stage managed to offer a dynamic range  of105dB with a signal / noise ratio of -90dB. DAC can be reached via the I2S connector and meets standard I2S format.

Note that it also hase a pin dedicated to volume (+ 12dB / -33dB & mute) if the connected device has a driver that supports this type of application.

The decoded audio stream is available for immediate use on a 3.5mm stereo jack connector which is already installed on the PCB.

A third 3.5mm stereo connector labeled "LINEIN" can bypass both ADC & DAC stages and facilitate connections.