Ok, my take on this is...
Putting the power plane and the ground plane next to each other does provide a hopefully uniform capcitor between power and ground across the entire board. Also, the transmission line impedence for traces running on one layer remain constant if the trace width remains constant. Extra layers of grounding can be added if you want to provide additional isolation between signals..
Signal layer Ground Power Signal layer
Gives you both the power to ground capacitive coupling and uniform transmission line impedence for both layers. if you wanted to add a third signal layer you might as well add a second ground layer (board vendors would just add a dummy layer to have an even number of layers for board warpage reasons).
So then you get the stack up of
Signal ground power signal ground signal
for each signal layer calculate the trace width for the desired impedence and....
Steve Meier
Karel Kulhavy wrote:
On Wed, Oct 20, 2004 at 09:07:48AM -0700, Steve Meier wrote:
Second, the power and ground planes should be inner layers. But for your frequencies I don't think you wil see many issues.
Why?
Cl<
