PCB Ground planes

[peranders]

The capacitance is approx. 3 pF for a 1 cm2 big object so for resistors we are talking about a fraction of an pF.

[marce]

We have numerous design that use various chip amps for both audio and instrumentation purposes, though mostly SMD, due to space constraints and complexity we use one contigous ground plane, no splits etc. We have never had any problems. If I was using through hole I would probably isolate the high current area's, but would still use a ground plane with possibly stragecic slots to isolate the high current paths, or totaly isolate these using flying leads (this technique is used in motor control where the PCB just will not carry the currents). But as a preference a solid ground is prefferable, especially when trying to get things passed for EMC.
There is a similar discussion here with some interesting links:

Analog and Digital Ground Planes - PCB Matrix Forum

Generaly when designing consumer products price plays a big big part, hence double sided boards are often used. I belive this will change as more stringent EMC requirements and availability of cheeper multilayer PCBs' from China will make multilayer PCB more prevelant in consumer goods. Some top end manufacturers all ready use the fact that they use multilayer as a marketing point.

But as said earlier we have not seen any degrading of signals etc by nusing a solid contigous ground.

[titoman]

Originally Posted by swordfishy

Hi All,

I'm designing a gainclone PCB and I'm just interested to know if PCB ground planes should be connected to the signal or chassis (power) ground?

Thanks for your help!

use two layers PCB; one layer for ground plane, other for connections with ground guard if possible.