I've placed a KSZ9031MNX Ethernet PHY on my board, and am now trying to get power routed to it. The digital side will merely be annoying to do, I think, but I'm at a complete loss on the analog side.
The analog supply pins are placed between the inner and outer signal pairs and I have no real good idea where to place those capacitors (except for the backside, which I'd like to avoid as these would be the only components there).
I've highlighted the positive supply pins and the corresponding pads on the capacitors I plan to use. The differential pairs going to the magnetics should be fairly obvious; I think these will have to be moved around a bit still.
My first attempt looks like this:
The traces on the bottom layer routing the power to the vias are still missing, but I think that might work.
Is it a good idea to have the capacitors bridge the differential traces to save space, or will that have negative effects on signal quality?
Should I try to keep the ground plane between the differential pairs, should I connect that area to analog ground to give the analog ground connection in the middle more copper, or is that irrelevant?