[SI-LIST] Re: AC Coupled Signals
- From: Jory McKinley <jory_mckinley@xxxxxxxxx>
- To: leeritchey@xxxxxxxxxxxxx, "npatel@xxxxxxxxxx" <npatel@xxxxxxxxxx>, si-list@xxxxxxxxxxxxx
- Date: Mon, 24 Sep 2007 14:31:37 -0700 (PDT)
I will elaborate a bit on what I have seen. I have measured (time domain) in
the lab some effects that appears to be location specific in the placement of
the AC coupling caps at the rcvr. Now this may be due in part to the fact that
I am using 50-ohm resistor termination in each lead as well and the combination
(cap plus rcvr reflection) is giving some imbalance depending on distance. The
best rcvr eye that I am seeing is when I can move the AC/term as close to the
rcvr as I can. By the way these are 5Gb/s signals.
If I have time I will try and isolate what I am seeing and even simulate it,
has anyone else seen or simulated this?
-Jory
----- Original Message ----
From: Lee Ritchey <leeritchey@xxxxxxxxxxxxx>
To: "npatel@xxxxxxxxxx" <npatel@xxxxxxxxxx>; si-list@xxxxxxxxxxxxx
Sent: Monday, September 24, 2007 1:06:06 PM
Subject: [SI-LIST] Re: AC Coupled Signals
Nikil,
I have made measurements on test PCBs and the location is not all that
important. In identical pairs, one with AC coupling capacitors and the
other without, the loss vs. frequency is virtually identical at leas out to
6 GHz. That would be 12 Mb/S.
Lee Ritchey
> [Original Message]
> From: <npatel@xxxxxxxxxx>
> To: <si-list@xxxxxxxxxxxxx>
> Date: 9/24/2007 10:21:37 AM
> Subject: [SI-LIST] AC Coupled Signals
>
> Hi all,
> In case of AC coupled signals does anyone know of an optimum placement
> for the caps? I mean should they be placed near the source, receiver,
> middle of the transmission line?
> How much difference does it make in the opening of the eye?
> The signals are differential CML running at 3.0Gbps
>
> Thanks,
> Nikhil
>
>
> ------------------------------------------------------------------
> 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
> 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
>
------------------------------------------------------------------
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
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
____________________________________________________________________________________
Moody friends. Drama queens. Your life? Nope! - their life, your story. Play
Sims Stories at Yahoo! Games.
http://sims.yahoo.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
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:
