Ground layout for mixed signals

Looks like SigmaDSP is the forum for questions on this part.

-Mark

Hello Elvis,

I recommend you use one ground plane with these parts. Just be careful with the parts placements with regards to return currents.

For AVDD and IOVDD you can use the same regulator but it is best to isolate the two using a ferrite bead and a cap to ground to clean up the AVDD or to keep the IOVDD noise from getting back into the AVDD.

Otherwise, you do not need to do too much efforts to isolate. I guess it will depend a little on your PCB implementation. Often people will use small thin flexible PCBs so you might run into issue where you need to make some extra effort to isolate the AVDD from the IOVDD. Your questions are difficult to answer because so much will depend on the physical details of your product.

A number of times I have implemented the exact same circuit on two different PCBs that were not exactly the same but close and ended up with some surprises with audio performance. PCB layout will humble the best of us.

Dave T

Thank you, Dave, for the clear explanation. I am also working hard on the layout here.