I would argue that there is a difference. Undershoot is defined by the = IEEE in standard 181-2003 as "3.1.49 undershoot: A waveform aberration = within a post-transition aberration region or pre-transition aberration = region that is less than the lower state boundary for the associated = state level." In layman's terms, undershoot does not require a preceding = overshoot. Ringback to me, again in simple laymans' terminology, is the = first (or lowest) dip AFTER an initial overshoot. "Ringback" to me = implies that there is some resonance, so one would expect to see a = damped sinusoid following a transition. There is no IEEE standard definition for "Ringback," but I believe it = has been defined in some semiconductor manufacturers' data sheets and = app notes. =20 Art Porter Agilent Technologies =20 -----Original Message----- From: si-list-bounce@xxxxxxxxxxxxx [mailto:si-list-bounce@xxxxxxxxxxxxx] = On Behalf Of Lee Ritchey Sent: Monday, May 22, 2006 9:02 AM To: Madhusudhan Kulkarni; si-list@xxxxxxxxxxxxx Subject: [SI-LIST] Re: Ring back Ringback is just another name for undershoot. I don't know why someone = had to invent another name for something that already had a name. When you have undershoot and you use series terminations, the terminator value it too high or the output impedance of the driver is too high. = When you have undershoot and you use parallel terminations, the value of the terminator is too low. Fix which ever problem you have by changing the value appropriately. > [Original Message] > From: Madhusudhan Kulkarni <madhusudhan@xxxxxxxxxx> > To: <si-list@xxxxxxxxxxxxx> > Date: 5/22/2006 9:28:26 AM > Subject: [SI-LIST] Ring back > > Hi, > How to solve ringback problem and what is the disadvantages of = ringback > ------------------------------------------------------------------ > 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 ------------------------------------------------------------------ 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 ------------------------------------------------------------------ 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