We have followed this recommendation for SSTL which is a low swing as well. The idea that stands behind it, is that if for any reason (i.e. noise) the driver's Vddq droops/bounces, it will affect the common mode of it's output swing. By allowing the Vref of the receiver to follow those changes (droop/bounce) the common mode of the receiver will follow the common mode of the transmitted signal. It sounds that what you suggest will work as well, I reckon once one decides to "cheat" and not follow the standard, as long as he follows the "spirit" of it he will be ok. Thank you for your remarks and for your suggestion, I will definitely will consider it in our next design Cheers, Gil Gafni -----Original Message----- From: steve weir [mailto:weirsp@xxxxxxxxxx] Sent: Wednesday, June 30, 2004 9:39 AM To: Gil Gafni; gopalak@xxxxxxxxxxx; si-list@xxxxxxxxxxxxx Subject: RE: [SI-LIST] Re: diff pair signal Gil, with LVDS I think that would be a very bad idea. LVDS is low swing and the swing references the internal power / ground nodes. If someone were going to try and cheat to reduce interconnects, I would take a single LVDS pair and hold it at a static level. Then use a 1:1 resistor divider between the two output leads as the reference for the single-ended "LVDS" signals. Regards, Steve. At 09:26 AM 6/30/2004 -0700, Gil Gafni wrote: >I would say that you want to take the transmitter's Vddq (IO voltage) >and generate the reference from it. This will allow the receiver's >input to follow any changes in the transmitter's rails. > >Cheers, > > > >Gil Gafni > > > >-----Original Message----- >From: si-list-bounce@xxxxxxxxxxxxx >[mailto:si-list-bounce@xxxxxxxxxxxxx] >On Behalf Of steve weir >Sent: Wednesday, June 30, 2004 8:12 AM >To: gopalak@xxxxxxxxxxx; si-list@xxxxxxxxxxxxx >Subject: [SI-LIST] Re: diff pair signal > > >In such a situation where do you think the diff amplifier will obtain >its reference? > >At 07:38 PM 6/30/2004 +0530, Gopalakrishnan Sethuraj wrote: > >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