[SI-LIST] Re: AC Coupling for SERDES Links across Backplane
- From: "Harjeet Randhawa" <harjeet.randhawa@xxxxxxxxxxxxxxxxx>
- To: "Vinu Arumugham" <vinu@xxxxxxxxx>, "steve weir" <weirsp@xxxxxxxxxx>
- Date: Fri, 29 Oct 2004 15:05:02 +0530
Hi Vinu,Steve,
The IOS on the chip are HOT SWAP capable.
Best Regards,
/---------------------------------------------------------/
Harjeet S Randhawa,
Nevis Networks India Pvt. Ltd,
B-101, Bhau Patil Marg,
34, Aundh Road, Pune - 411 020.
Tel: +91-20-403-3900, Xtn:290,
Fax:+91-20-403-3904,
Cell: 0-9890130611.
/--------------------------------------------------------/
-----Original Message-----
From: Vinu Arumugham [mailto:vinu@xxxxxxxxx]=20
Sent: Friday, October 29, 2004 1:24 AM
To: Harjeet Randhawa
Subject: Re: [SI-LIST] AC Coupling for SERDES Links across Backplane
If you need to support hot-insertion or powered down line cards, AC=20
coupling makes it easier.
Thanks,
Vinu
Harjeet Randhawa wrote:
>Hi All,
>
>The XAUI spec mandates putting the AC coupling CAPs for the SERDES
links
>to allow inter-operability among different SERDES technology vendors
due
>to probable different internal BIAS levels.
>
>But for the scenarios where the SREDES cells are same does it helps in
>any way to AC Couple the SERDES links. The scenarios may be where there
>is 40" of PCB trace running from a line card to backplane and finally
to
>a Fabric Card.
>
>The SERDES cells are matched in the sense that they are having same
>characteristics and from same vendor. The BIAS voltage is generated on
>board with 5% regulation. I do not expect any high current transients
on
>the BIAS voltage and it is well filtered and decoupled.
>
>Also there is a consistent Ground Plane bridging at backplane
connectors
>so the GND differential across the TX to RX points should not cause any
>significant BIAS reference shifts.
>
>The whole issue is due to fact that the Transmit Pairs of the SERDES
are
>2-3 rows deep in the package so adding the AC Cap will force to add two
>more VIAs on the routes adding to deterioration of the signaling
>quality.
>
>Thanking all in advance for their valuable suggestions.
>
>Best Regards,
>/---------------------------------------------------------/
>Harjeet S Randhawa,
>Nevis Networks 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 FAQ wiki page is located at:
> http://si-list.org/wiki/wiki.pl?Si-List_FAQ
>
>List technical documents are available at:
> http://www.si-list.org
>
>List archives are viewable at: =20
> //www.freelists.org/archives/si-list
>or at our remote archives:
> http://groups.yahoo.com/group/si-list/messages
>Old (prior to June 6, 2001) list archives are viewable at:
> http://www.qsl.net/wb6tpu
> =20
>
>
> =20
>
------------------------------------------------------------------
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 FAQ wiki page is located at:
http://si-list.org/wiki/wiki.pl?Si-List_FAQ
List technical documents are available at:
http://www.si-list.org
List archives are viewable at:
//www.freelists.org/archives/si-list
or at our remote archives:
http://groups.yahoo.com/group/si-list/messages
Old (prior to June 6, 2001) list archives are viewable at:
http://www.qsl.net/wb6tpu
Other related posts:
