[SI-LIST] Re: Crosstalk ( forward )
- From: Praveen Gowda <praveenkumardr@xxxxxxxxx>
- To: si-list@xxxxxxxxxxxxx
- Date: Sat, 9 Jan 2010 18:45:46 +0530
Thank you Doug Brooks,
So, For a given FIXED condition of two T Lines having a parallel running
length of about 1" lets say, of total 6" each.
then for a single data transition, say low to high, 0 to1, then
at the receiver end of victim line, f/w cross talk is seen as a growing (to
a finite value) pulse of fixed period, as it traverses down the victim line,
passing through aggressor-victim parallel lengths. (assuming capacitive f/w
x_talk dominates)
at the driver end of victim line, b/w cross talk is seen as pulse of fixed
amplitude (depends on parallel length) with its duration growing till it
becomes 2 x length of aggressor line.
Thanks and Regards
Praveen
On Thu, Jan 7, 2010 at 12:30 AM, Doug Brooks <dbrooks9@xxxxxxxxxxxxxxx>wrote:
> Think of it this way.
> At a given point on the victim trace, the rising edge of the aggressor
> trace creates a pulse that is the same width as the rise time of the
> aggressor pulse and whose amplitude peaks at about the midpoint of the
> aggressor pulse.
> Now that induced pulse on the victim trace travels in the forward direction
> at the same propagation speed as the aggressor signal travels on its trace.
> So at each pint along the victim trace you have the effects of the coupling
> at prior points along the trace (moving along at the same speed) plus the
> new coupling occurring coincidentally at that point. The effect is a
> continuous summing of the aggressor coupling at each point along the trace.
> Thus, the longer the coupled region, the more summing that occurs and the
> stronger the forward crosstalk signal becomes.
>
> We have some good articles about crosstalk on our web site and two good
> chapters about it in our book.
>
> Doug Brooks
> http://www.ultracad.com
>
>
>
>
>
> At 12:43 AM 1/6/2010, you wrote:
>
>> Hi,
>> why forward crosstalk amplitude pile up ( adds up for every voltage
>> transition in aggressor) ?
>> (f/w xtalk is the resultant of capacitive f/w xtalk which is +ve spike,
>> i(t)=C dv/dt and inductive f/w xtalk v(t) = - Ldi/dt, which is -ve spike
>> ,
>> for zero to one, positive transition of the voltage in aggressor line).
>>
>> Rather it could have traveled as
>> individual spikes (spike duration being transition time which is same as
>> rise time, tr) periodically separated by a period ( period being time span
>> between each transition) !
>>
>> Thanks and Regards,
>> Praveen
>>
>>
>> ------------------------------------------------------------------
>> 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
>>
>>
> Check out our resources at http://www.ultracad.com
>
------------------------------------------------------------------
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:
