What the title says. I'm curious how exactly a digital potentiometer works. Is it something like a pair of pass transistors like below?
Or is it more like a series of switched resistors like below?
Or is it something else entirely, that I can't think of?
I looked around, and found exactly one source suggesting that it is the latter case, but I couldn't find anything else talking about the internals of a digital pot at all. Maybe there's more out there, though, and I'm just really bad at finding things.