I have a board that has a dual voltage isolated DC-DC converter on it.
The converter takes 0 an 5v in and gives -5,0,5 v out.
The 0v of the input is actual ground.
Most of the PCB uses the isolated voltages.
Should I use ground and 5V (input) as my planes?
Or should I use 0v (isolated) for the underside plane, and some other value for the top side plane?