[SI-LIST] Re: Maximum length of 2.5G SerDes trace
- From: Mashook Ahamed Usman <MashookAhamed.Usman@xxxxxxxxxxx>
- To: "wolfgang.maichen@xxxxxxxxxxxx" <wolfgang.maichen@xxxxxxxxxxxx>
- Date: Thu, 19 Nov 2009 09:46:51 +0530
Hi Wolfgang,
Thank you very much for the detailed reply. Shall look into it as per your
suggestions.
Regards,
Mashook Usman
________________________________
From: wolfgang.maichen@xxxxxxxxxxxx [mailto:wolfgang.maichen@xxxxxxxxxxxx]
Sent: Thursday, November 19, 2009 1:43 AM
To: Mashook Ahamed Usman
Cc: si-list@xxxxxxxxxxxxx; si-list-bounce@xxxxxxxxxxxxx
Subject: Re: [SI-LIST] Maximum length of 2.5G SerDes trace
Hi,
the number of layers is of no direct importance. The main factors are
- trace width (determines skin loss)
- dielectric material (determines dielectric loss tangent)
- trace configuration (stipline, microstrip, CPW)
- via parasitics
- driver and receiver noise
- do transmitter/receiver use some sort of pre-emphasis or de-emphasis
As a VERY ROUGH starting point - please don't bet your company's future on it
without verifying with a decent simulation tool - in a 4mil wide stripline
trace in FR-4, neglecting via parasitics, and assuming no pre-emphasis, for a
data rate of 2.5 GB/s, you can go approx. 20 inches before the data eye closes
too much.
For a first order approximation - so you can get a rough feeling of where your
actual design is - there is a very nice web-based tool (freeware!) by Tom
Clupper that allows you to play with all these parameters (including
pre-emphasis and rough via models) and look at the data eye, TDR response,
frequency response etc of your path:
http://www.tlinesim.com/
Hope that gets you going
Wolfgang
Mashook Ahamed Usman <MashookAhamed.Usman@xxxxxxxxxxx>
Sent by: si-list-bounce@xxxxxxxxxxxxx
11/18/2009 04:00 AM
To
"si-list-bounce@xxxxxxxxxxxxx" <si-list-bounce@xxxxxxxxxxxxx>
cc
"si-list@xxxxxxxxxxxxx" <si-list@xxxxxxxxxxxxx>
Subject
[SI-LIST] Maximum length of 2.5G SerDes trace
Hi,
It would be useful if I know the maximum length of 2.5G SerDes trace that can
travel in a 14 layer board in which the reference plane(Ground) is adjacent to
it.
Thank you very much,
Mashook Usman
________________________________
"DISCLAIMER: This message is proprietary to Aricent and is intended solely for
the use of the individual to whom it is addressed. It may contain privileged or
confidential information and should not be circulated or used for any purpose
other than for what it is intended. If you have received this message in
error,please notify the originator immediately. If you are not the intended
recipient, you are notified that you are strictly prohibited from using,
copying, altering, or disclosing the contents of this message. Aricent accepts
no responsibility for loss or damage arising from the use of the information
transmitted by this email including damage from virus."
------------------------------------------------------------------
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
________________________________
"DISCLAIMER: This message is proprietary to Aricent and is intended solely for
the use of the individual to whom it is addressed. It may contain privileged or
confidential information and should not be circulated or used for any purpose
other than for what it is intended. If you have received this message in
error,please notify the originator immediately. If you are not the intended
recipient, you are notified that you are strictly prohibited from using,
copying, altering, or disclosing the contents of this message. Aricent accepts
no responsibility for loss or damage arising from the use of the information
transmitted by this email including damage from virus."
------------------------------------------------------------------
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:
