[SI-LIST] Re: Cross talk and Trace length
- From: bala <balaseven@xxxxxxxxx>
- To: "si-list@xxxxxxxxxxxxx" <si-list@xxxxxxxxxxxxx>
- Date: Wed, 17 Aug 2011 23:19:47 +0530
On Aug 17, 2011 11:14 PM, "bala" <balaseven@xxxxxxxxx> wrote:
> Rajesh...one thing on the SI its always depends on the substrate and
> speed...no formula like ohms law...it depends...material is first
think,dont
> send data with high speed and dont specify distance and space.finally to
> avoid crosstalk 4x or some x is no mattet analyze the channel with
> speed.thats my answer.
> On Aug 17, 2011 6:47 PM, <J_Dong@xxxxxxxxxxxxxxxx> wrote:
>> Rajesh,
>> I am not a SI expert, but I think this is too general a matter to be
>> answered explicitly. The coupling or isolation between two adjacent pcb
>> traces could largely depend on the
>>
>> 1. freq. Assuming microstrip pcb, different freq will give different
>> fringing field distributions around the trace as well as see different
>> effective trace spacing, which would result in different couplings.
>>
>> 2. the load of each trace. Depending on whether you have matched or
>> discontinuities along either trace, resonant modes might be created. In
> some
>> filter design, you can even achieve 99% coupling between two tracings
even
>> you have pretty wide trace spacing.
>>
>> 3. other physical identifies like dielectric constant of the substrate,
>> height of the board etc. Those factors affect aforementioned issues too.
>>
>> The best solution to that is to turn to the "virtual reality"! The ever
>> growing solvers based on numerous types of numerical techniques (FEM,
> Finite
>> Difference, MoM, etc) could accurately solve the Maxwell equations for
>> arbitrary geometries. You give it a 2D/2D geometry and right boundary
>> conditions, it gives you a right answer. Products range from 0 dollars
> (e.g.
>> GMSH, GetDP http://www.geuz.org/getdp/) to a few tens of thousands of
>> dollars (e.g. HFSS, CST, etc) are options for people to choose. For this
>> particular question, I would just suggest getting a free trial version of
>> some commercial software is sufficient, for example free trail FEKO at
>> http://www.feko.info/.
>>
>> Hope it helps.
>>
>> Junwei Dong
>>
>> -----Original Message-----
>> From: si-list-bounce@xxxxxxxxxxxxx [mailto:si-list-bounce@xxxxxxxxxxxxx]
> On
>> Behalf Of steve weir
>> Sent: Wednesday, August 17, 2011 4:20 AM
>> To: si-list@xxxxxxxxxxxxx
>> Subject: [SI-LIST] Re: Cross talk and Trace length
>>
>> Your question fills a good chapter in many of the texts out there such
>> as "Signal Integrity Simplified" Bogatin, "High Speed Digital Design"
>> Johnson, etc. There are also excellent web tutorials.
>>
>> Steve.
>> On 8/17/2011 12:19 AM, rajesh kumar wrote:
>>> Hello SI Gurus,
>>> Please share your thoughts on the relationship between
>> cross
>>> talk and trace length. In general i consider that the spacing between
>> trace
>>> is the main factor that influences cross talk. Still now i assume that
4X
>>> spacing between traces (X is a trace width) is a good way to avoid cross
>>> talk irrespective of the length of trace. Please share your views on
> this.
>>>
>>> Thanks,
>>> Rajesh
>>>
>>>
>>> ------------------------------------------------------------------
>>> 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
>>>
>>>
>>>
>>
>>
>> --
>> Steve Weir
>> IPBLOX, LLC
>> 150 N. Center St. #211
>> Reno, NV 89501
>> www.ipblox.com
>>
>> (775) 299-4236 Business
>> (866) 675-4630 Toll-free
>> (707) 780-1951 Fax
>>
>>
>> ------------------------------------------------------------------
>> 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
>>
>>
------------------------------------------------------------------
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:
