[SI-LIST] Re: crosstalk and pcb placement of buses on high density pcb's
- From: rod <rod@xxxxxxxxx>
- To: Bernadine Splettstoeszer <bernadineps@xxxxxxxx>
- Date: Fri, 02 Dec 2011 15:41:38 -0600
The edge rate and net length are important for microstrip.
So for microstrip, crosstalk increases with faster edge rates and
longer lines (parallelism).
For stripline, the voltage is constant after saturation length which
is the edge rate distance.
So for stripline, the edge rate (distance) just tells you how long the
trace needs to be before saturation voltage and after
that length there is no increase in crosstalk voltage. Faster drivers
do not cause more crosstalk, just shorter saturation length.
And longer lines also do not cause more crosstalk.
Hope that helps
-rod strange
Fast Edges
On 12/2/2011 3:04 PM, Bernadine Splettstoeszer wrote:
> How does one decide which interfaces to route next to one another on a
> tighlty spaced pcb if xtalk is a concern. In other words if edge rate and
> net length are the primary contributors does one select interfaces that are
> relatively slow (JTAG) to place next to those that are relatively faster
> (50MHz)? What about those High Speed interfaces like PCIe Gen 1-3 is it best
> to place those next to siganls whose edge rates are> 1ns? I am looking for
> some general rules or practices.
>
> When working with high density small form factor pcb's there are going to
> have to be trade-offs, what are the recommendations when working with
> non-ideal spacing properties?
>
> Thanks
>
> B
> ------------------------------------------------------------------
> 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:
> //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:
> //www.freelists.org/archives/si-list
>
> 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:
//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:
//www.freelists.org/archives/si-list
Old (prior to June 6, 2001) list archives are viewable at:
http://www.qsl.net/wb6tpu
Other related posts:
