a question about Power Planes

[qasmi]

Hello everyone,

I am designing a 4-layer pcb with 2 power planes (Vcc and GND) . The GND plane is further split into Agnd-Dgnd and the Power plane is split into +5V,-5V,+3.3AV, and +3.3DV.

what check list or Rules of thumb should I take into account for designing a multi-Layer pcb in general and this design in particular. A quick response will be appreciated. Thanks



Regards

Added after 3 minutes:

One more question I forgot to mention, What effect will the overlapping of different powers in VCC plane (i.e. +5V,-5V,+3.3AV, and +3.3DV) and GND plane have on the PCB. Thanks once again ......

 

[Rame]

Hi,

Here are some of the links which will help you for your above subject..


http://www.hottconsultants.com/techtips/pcb-stack-up-6.html
**broken link removed**
http://www.sigcon.com/Pubs/edn/diffuturn.htm
http://www.sigcon.com/Pubs/news/9_04.htm
**broken link removed**
http://www.sigcon.com/Pubs/news/2_26.htm
**broken link removed**
http://www.hottconsultants.com/pdf_files/june2001pcd_mixedsignal.pdf
An application note from Analog Devices at:
http://www.analog.com/UploadedFiles/Application_Notes/294542582256114777959693992461771205AN280.pdf
And some good ideas on page 7 of:
http://www.analog.com/UploadedFiles/Application_Notes/495266810AN-404.pdf

Hope this helps you...

Regards

Ramesh

 

[chinta]

good links ramesh

 

[tdt]

1. All highspeed signals must be routed in one reference plane area.
2. If you change layer , make sure that you sandwich a gnd plane and if not
you can add via everytime you do a change layer.
3. Don't cross the highspeed signal on split planes.
4. Route signals on layers that reference to a gnd PLane layer.