I have a question about the adau1761 setting.
1. I'm trying to use one analog microphone. How do you connect to adau1761 analog input and process the remaining unused analog input ports?
2. Please refer to PCB design to minimize white noise as much as possible.
3. When you use one analog microphone, does the Sigma Studio's Record Input Signal Path activate IN 1?
The best way to see the signal flow is to open up the Register Controls in SigmaStudio. You can see it all on one page. Well, the entire input flow on one page and the entire output flow on another. You can run the signals any way you like. It is very flexible. You can only use one of the inputs. The unused inputs can be left floating or terminated through a cap to ground. You can also use the CM voltage, but if you do that it would be best to buffer the CM voltage.
You will need to shut off the signal from unused inputs to keep the noise down.
For PCB design, I recommend you use at least a 4-layer board with the internal layers being power and ground. Then look at the PCB Design Considerations that is in the ADAU1452 datasheet. There it explains how to tie to the power pins of the part and then tie to power and ground plans in a manner that makes the bypass cap much more effective. This will help keep outside noise from the part and it will also help keep noise generated from within the part from going out onto the planes. Do this will all the parts in your design wherever possible.
Dear Dave T
Thank you for your quick response.
I will proceed with development based on what you have mentioned.
Thank you very much.