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Hi All,I'm currently designing an analog audio two layer pcb, with power and signals on top layer, and ground plane in bottom.
I use dual opamps like ne5532 lm833p, and two 24v dpdt relays. Now i'm laying out the power traces, and sometimes it gets a bit difficult to trace supply lines for every opamp.
I still have to try 4 layer board design, and related to 4 layer i have a question.:
¿ is it possible to design a DUAL supply power plane? usually searching on the net i see SINGLE supply power planes, as used for digital stuff... but not dual.
My objective is not to break the ground plane too much, with vertical traces.
I try to follow the criteria: " ground follows signal",
and as far i have seen/read, power and ground should follow the same path..
to avoid ground loops...
Besides there is the ground plane: With it, and thermal pads ¿can i avoid the use of a ground tree or star ground?
You must create your hierarchical ground (that's the accepted name for "ground follows signal") and then manage the polygon that defines the copper pour in such a way that your ground plane is just your swollen original ground track. The polygon should start at the rails reference point (either the 0V connection if power is separate - make sure the common of decoupling caps is connected via a solid track to this point - or the regulators reference if power is on board).
¿is there a method to see/expect current circulation path?
Noise/EMC wise, i will stitch both layers around the perimeter of the board. ¿Is it bad for crosstalk to have parallel traces on opposite layers?
for example: balanced summing inputs: + input on top layer an - input on the bottom, parallel
¿Or better is that each trace has ground plane opposite?