[SI-LIST] Re: diff pair signal

  • From: steve weir <weirsp@xxxxxxxxxx>
  • To: gil.gafni@xxxxxxxx, <gopalak@xxxxxxxxxxx>,<si-list@xxxxxxxxxxxxx>
  • Date: Wed, 30 Jun 2004 09:53:25 -0700

Gil, I don't know of any specific problems with leaving one leg of an LVDS 
driver open but it might cause some timing issues as the current source 
goes from unloaded to loaded.  We disagree on how best to get a reliable 
switching reference as noted in earlier postings.  Given the low swing of 
LVDS, if it is a poor man's translator, AC coupling would seem mandatory 
due to the low swing.

Regards,


Steve.
At 09:35 AM 6/30/2004 -0700, Gil Gafni wrote:
>To my humble opinion, it is all about the transmitter (driver).
>
>If it a true current logic, like the LVDS and alike, you have to close
>the current loop, otherwise it will not work properly (or at all)...
>If you driver is build of two "independent" drivers it will be easier.
>In such case you can connect one output to the receiver.
>You will have to address few issue though:
>1. What should you do with the other output, i.e. can you leave it open
>or is would you need any termination
>2. assuming that the receiver is not a single ended, you will have to
>address the Vref, I would recommend to generate it from the driver's
>Vddq (IO voltage)
>3. Do you need to AC couple
>
>And so on
>
>By the way there are plenty of Application Notes that discuss single to
>diff, to name one -
>http://www.saronix.com/pdf/applications/AN047.pdf
>
>Good luck
>
>
>Cheers,
>
>
>
>Gil Gafni
>
>
>
>-----Original Message-----
>From: si-list-bounce@xxxxxxxxxxxxx [mailto:si-list-bounce@xxxxxxxxxxxxx]
>On Behalf Of Gopalakrishnan Sethuraj
>Sent: Wednesday, June 30, 2004 7:09 AM
>To: si-list@xxxxxxxxxxxxx
>Subject: [SI-LIST] diff pair signal
>
>
>Hello
>
>
>Is there any scenario where one (positive)  of the  differential pair
>signal output  will be connected to single pin in LVDS or other logical
>interfaces ?
>
>
>
>
>
>Thanks&Regards
>
>Gopalakrishnan
>
>
>
>
>------------------------------------------------------------------
>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
>
>
>
>------------------------------------------------------------------
>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
>


------------------------------------------------------------------
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: