Several instances in the past I have come across the need for virtual grounds, often in audio and communication situations. Working with datasheets and application notes, on one particular audio design, I could not find anything in their designs that would give me the virtual ground that was constantly being referenced. The virtual grounds were being referenced everywhere, and other engineers that were working with me wanted to just tie those grounds to the return path of the circuit. I differed on their opinion, and two prototypes were made.
One where all the virtual grounds were tied to the negative terminal of the supply, the other engineer's idea, did not function at all. I watched them tinker with that PCB for almost a week with no results.
The one I had made used this sort of set up at the source:
And it, for the most part, worked and played sounds. However, I was not satisfied with the result, past lording my triumph over my fellow engineers. I felt it was an ad hoc sort of Band-Aid or the project.
What are the absolute standards in adding a virtual ground to a system? What are the best practices and references on the subject?
Cabe
