Re: 8 Layer Board - Non-standard Stackup

On Wed, 30 Jan 2008 12:21:00 -0800 (PST), namdeguerre@xxxxxxxxx wrote:

When you mean separate ground areas for each, do you mean separate
grounds for each linear regulator output - Currently, my ground plane
is the same for all the regulator outputs. I can separate them,
however this will mean more complications as each 4 linear regulators
link to one switcher which links to the main ground from the PC
supply.
I said it gets complicated... depends a lot on your signal paths and the type of
chips in use. For instance programmable gain amps have digital and analogue
signals and supplies (although the digital control lines can be held static
during measurement).ADCs have analogue and digital grounds and require the
(electronic) design engineer to specify where he wants them joined. This can
give problems where there is more than one ADC. In this case I used to provide
several solder link pads by the chips to let them experiment to find the optimum
for their purposes.

Geo
.