Nidhir, The GDDR3 driver is actually a POD (pseudo open drain) driver. There is a device to pull down (40 ohms) and a device to pull-up (60 ohms). It is weaker than the 40 ohm pull down device but it is there to help the 60 ohm resistor at the far end pull up the signal line. -------------------------------------------------------------- | Bill Cohen | Toshiba America Electronic Components | Mixed Signal Design Group -------------------------------------------------------------- "Nidhir Kumar" <nidhir.kumar@gma il.com> To Sent by: si-list@xxxxxxxxxxxxx si-list-bounce@fr cc eelists.org Subject [SI-LIST] effect of termination on 03/13/2006 03:12 slew rate PM Please respond to nidhir.kumar@gmai l.com Dear Gurus I am designing graphical DDR3 driver which has 40 ohm push-pull driver and 60 ohm termination (ODT) to the VDDQ at the far end. Since the termination is to the supply, I would assume that rise slew at the far end should be higher. But rise and fall slews looks very symmetrical in the HSPICE simulations. Can someone please explain me the theory behind this phenomenon. I read somewhere that DC terminations don't affect AC behavior. But I find it difficult to digest. Any thoughts? Thanks, Nidhir ------------------------------------------------------------------ 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