[sdiy] PCB layout rules

[John Luciani]

On 12/22/06, Laurie Biddulph <elby_designs at ozemail.com.au> wrote:
> If a design uses DGND (Digital GND) and AGND (Analog GND) would it make
> sense to take ALL decoupling capacitors DGND (irrespective of whether they
> are analog or digital circuits) and thus leave the AGND purely as your
> `reference' GND? Or would the introduction of the DGND throughout the whole
> board cause more problems than it solves?

It would depend on the size of the currents and the frequencys. At 100MHz
I believe copper is a few mOhms per square. Your currents would have to be
very large or your voltages very small to see any affect. If you start chopping
up the plane you are going to end up with a lot more squares.

For sdiy I think you better off with the "let ground abound" approach
rather than chopping
up your planes.

(* jcl *)

-- 
http://www.luciani.org