Another development – ADC on CS5381.
To date, to digitize the audio signal is not such a large selection of IC ADC.
When designing its first ADC, the following requirements were made:
- low level THD + N, not worse than -110 dB
- ease of use
ADC with characteristics that meet the requirements:
Because Cirrus Logic freely sent a CS5381 sample, this was the starting point.
Output – I2S, by default, the ADC works as a master on the I2S bus. As a WM8805 transmitter, coaxial and optical output. It is also possible to exit on CS8406.
The scheme is quite simple. The digital part stabilizer on 1117-3.3, the generator power is separated by inductance. The generator frequency is 24.576 MHz. To operate at such a masterclock frequency, you must enable the frequency divider in the ADC.
Analog input filter is made on a fully differential op-amp, switching circuit by datasheet. Analog circuit power supply on TPS7A series stabilizers.
Printed circuit board 2x stronya, size 50×100 mm. Boards are made in China.