[SI-LIST] Re: Effect of Split Planes on Single Stripline Signals
- From: steve weir <weirsi@xxxxxxxxxx>
- To: wolfgang.maichen@xxxxxxxxxxxx
- Date: Thu, 10 Jun 2010 10:22:45 -0700
wolfgang, I've written my share of sleep deprived posts. The spacing
ratio is high enough that the impedance discontinuity is unlikely to
disturb his signals meaningfully. The aggregate energy directed down
the slot, could however create EMC issues.
Best Regards,
Steve
wolfgang.maichen@xxxxxxxxxxxx wrote:
> Steve,
> somehow how I saw "differential" in the original post - probably should
> not answer technical questions after midnight :-) Single ended signals
> will of course see quite a bit larger discontinuities. Sonnet Lite will be
> able to tell Walter how much.
>
> Wolfgang
>
>
>
>
>
> steve weir <weirsi@xxxxxxxxxx>
> Sent by: si-list-bounce@xxxxxxxxxxxxx
> 06/10/2010 12:05 AM
>
> To
> wolfgang.maichen@xxxxxxxxxxxx
> cc
> Walter <waltinaustin@xxxxxxxxx>, si-list@xxxxxxxxxxxxx,
> si-list-bounce@xxxxxxxxxxxxx
> Subject
> [SI-LIST] Re: Effect of Split Planes on Single Stripline Signals
>
>
>
>
>
>
> wolfgang, DDR3 clock and data strobes are differential. All other
> signals are single-ended. Walter will still probably be OK SI-wise.
>
> Best Regards,
>
>
> Steve.
>
> wolfgang.maichen@xxxxxxxxxxxx wrote:
>
>> Hello Walter,
>> based on past simulations and experiments of similar cases my educated
>> guess is that with the given dimensions, the fact that the line is
>> differential and the closer reference plane does not have a split, as
>>
> well
>
>> as the relatively low bandwidth (what are your rise times? I'd guess
>> around 200ps?) reflection will be minimal (meaning of the order of 1-2%
>>
> or
>
>> less). But I would highly recommend running your own simulations first,
>> before manufacturing the board. One tool that can handle your structure
>> (and which I used myself in my simulations) would be Sonnet Lite. It's
>> free so you can't lose anything (other than a few hours of your time).
>> Make sure to take advantage of your structure's symmetry (Sonnet has a
>> checkbox to tell the solver to assume a symmetric structure) as this
>> reduces memory requirements and thus either speeds up the calculation or
>>
>
>
>> allows you to simulate with greater precision (finer subdivisions).
>> Since the Lite version only allows two metal layers use top and box
>>
> cover
>
>> as additional layers - that way you can simulate all four layers of your
>>
>
>
>> structure (solid plane, signal layer, broken plane, adjacent solid
>>
> plane).
>
>> Disclaimer - I am in no way affiliated with Sonnet, apart from using
>> Sonnet Lite myself.
>>
>> Wolfgang
>>
>>
>>
>>
>>
>>
>> "Walter" <waltinaustin@xxxxxxxxx>
>> Sent by: si-list-bounce@xxxxxxxxxxxxx
>> 06/09/2010 02:00 PM
>>
>> To
>> si-list@xxxxxxxxxxxxx
>> cc
>>
>> Subject
>> [SI-LIST] Effect of Split Planes on Single Stripline Signals
>>
>>
>>
>>
>>
>>
>> I have an application were I am contemplating routing signals across
>> splits in a plane. Everyone know that this is a big no no for high speed
>>
>
>
>> signals. But in this case, it's a asymmetric single stripline. The
>>
> traces
>
>> are 12 mils from a split plane and 3mils from a solid plane. Can I
>>
> expect
>
>> a measurable effect on my DDR3 1600 signals? I would like to simulate
>>
> this
>
>> with a 3d solver but I don't have access to one.
>>
>> Regards,
>> Walter Haskell
>> Polycom. Inc.
>>
>>
>> ------------------------------------------------------------------
>> 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
>>
>>
>>
>>
>>
>
>
>
--
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
Other related posts:
