I prefer the separation at the schematic level and connect with a
component in some way; either a bead or a multi-pin gnd -- where
there would a connection internally on the component at the pcb
level in some way, a Cu pour for example. I again, prefer the bead.

Scott
IDS

Khaled Hassan wrote:
>
> Dear fellow designers,
> I am working now on a design with a mixed signal ,i.e. analog and
> digital.
> What I understand is that ,from the EMC point of view ,you have to
> separate between the two grounds, the analog ground and the digital
> ground. My question is how are you going to connect them at the end,
> directly (short circuit) or through a component (e.g. ferrite bead). One
> of the reasons I want to do that, is to know if I have to separate the
> two grounds right from the beginning,i.e. on the schematic, or shall I
> leave it till the layout and then keep it in mind to connect them
> directly. And what is the preferable grounding scheme for that type of
> designs.
> Any help is appreciated.
>
> --
> Best Regards
> Khaled H. Fouad
> PCB Designer / R&D Department
> Tel.: +20 (11) 333414  Ext. : 312       Fax.   : +20 (11) 335613
> BAHGAT Group    http://www.bahgat.com
> Email  : [log in to unmask]
> Second Industrial Zone, Plot 240, 6 October City, Egypt