Hello everyone. I am currently laying out a mixed signal board and am looking for some clarification on analog and digital ground planes for which I did a general Google search but did not get my questions directly answered.
Question 1:
Which one would be the better scenario in terms of decreasing the amount of digital noise being injected into my circuit’s sensitive analog ground plane assuming I have a 2-layer board and one ADC?
A: Connecting both the analog and digital ground planes with a thin trace under the ADC and then connecting the ground coming from the voltage regulator to that point sort of like a single point/star ground.
B: Connecting both the analog and digital ground planes with a thin trace under the ADC and then connecting the ground coming from the voltage regulator to the digital ground plane which may be far away from the thin trace.
Question 2 (and many sub-inquires):
Say, for example, I had two independent voltage converters which are used to separately provide power for the digital and analog sides of my circuit. In addition, the source for the two converters comes from a single battery.
Would I then supply each side’s respective ground plane with their own ground trace from their respective converters?
Would that then shift the common connection between the digital and analog ground planes to where the grounds of the converters meet – the ground of the battery feeding into the board?
If so, would I still provide a connection between the analog and digital ground planes near the ADC? <-Ground loop?
Thanks.