[SI-LIST] Re: How much plane under traces is required for providing return current path

Sorry, there was a small typo in my precious message, it should read as follows:
Hello Erin;
The width of the return path actually being used by the return current depends 
primarily on the separation between the return plane and the signal trace. The 
width of the signal trace is a second order effect. A return path width of 
seven 
times the separation is a good place to start.

Syed M. Husain.



-------------- Original message -------------- 
From: syedmhusain@xxxxxxxxxxx 

> Hello Erin; 
> The width of the return path actually being used by the return path depends 
> primarily on the separation between the return plane and the signal trace. 
> The 
> width of the signal trace is a second order effect. A return path width of 
> seven 
> times the separation is a good place to start. 
> 
> Syed M. Husain. 
> 
> -------------- Original message -------------- 
> From: Erin.McPhalen@xxxxxxxxxxxxxxxxxxxxxxxxx 
> 
> > Hi 
> > We are in the process of laying out a PCB, due to safety requirements we 
> > can not provide a full coverage ground plane in one section of our 
> > circuit. In this area high speed signals are required to travel to other 
> > components (100 MHz, 1ns edge rates). We do have room to place a 
> > restricted ground plane under these traces to help reduce emissions and 
> > control impedances. What would be considered the minimum ground plane 
> > width to provide sufficient coverage to control impedance and provide a 
> > return path? Would 20H be a good start? 
> > 
> > Erin 
> > 
> > 
> > ------------------------------------------------------------------ 
> > To unsubscribe from si-list: 
> > si-list-request@xxxxxxxxxxxxx with 'unsubscribe' in the Subject field 
> > 
> > or to administer your membership from a web page, go to: 
> > http://www.freelists.org/webpage/si-list 
> > 
> > For help: 
> > si-list-request@xxxxxxxxxxxxx with 'help' in the Subject field 
> > 
> > 
> > List technical documents are available at: 
> > http://www.si-list.net 
> > 
> > List archives are viewable at: 
> > http://www.freelists.org/archives/si-list 
> > or at our remote archives: 
> > http://groups.yahoo.com/group/si-list/messages 
> > Old (prior to June 6, 2001) list archives are viewable at: 
> > http://www.qsl.net/wb6tpu 
> > 
> > 
> 
> ------------------------------------------------------------------ 
> To unsubscribe from si-list: 
> si-list-request@xxxxxxxxxxxxx with 'unsubscribe' in the Subject field 
> 
> or to administer your membership from a web page, go to: 
> http://www.freelists.org/webpage/si-list 
> 
> For help: 
> si-list-request@xxxxxxxxxxxxx with 'help' in the Subject field 
> 
> 
> List technical documents are available at: 
> http://www.si-list.net 
> 
> List archives are viewable at: 
> http://www.freelists.org/archives/si-list 
> or at our remote archives: 
> http://groups.yahoo.com/group/si-list/messages 
> Old (prior to June 6, 2001) list archives are viewable at: 
> http://www.qsl.net/wb6tpu 
> 
> 

------------------------------------------------------------------
To unsubscribe from si-list:
si-list-request@xxxxxxxxxxxxx with 'unsubscribe' in the Subject field

or to administer your membership from a web page, go to:
http://www.freelists.org/webpage/si-list

For help:
si-list-request@xxxxxxxxxxxxx with 'help' in the Subject field


List technical documents are available at:
                http://www.si-list.net

List archives are viewable at:     
                http://www.freelists.org/archives/si-list
or at our remote archives:
                http://groups.yahoo.com/group/si-list/messages
Old (prior to June 6, 2001) list archives are viewable at:
                http://www.qsl.net/wb6tpu

Other related posts: