hello Arpad, i mistakenly took for granted that you had read the IEEE papers referred by Herbert, more so because it quotes one of your papers as reference (which i could not trace). Anyway, the alpha and beta are same/similar to the Kpu_rise and Kpd_fall. Yes, i got the point you made that the Vt curves correspond to gate voltages which, in turn, is related to time since the gate voltage develops(fall/rise) with time. I now hope things are pretty clear to me. Thanks to you and all others on the SI-list for helping me understand about what IBIS represents and how it is interpreted by simulators. regards ADEEL > > Adeel, > > I am not sure what you are referring to as alpha and beta, because > I haven't read that paper. The way I explain this is that the Vt > curves are basically used to regenerate the family of IV curves > which correspond to all gate voltages between power and ground. > This can also be viewed as a scaling factor of the IV curves with > respect to time. > > However, the IV curve's output current is also a function of the > drain-source voltage, which depends on the loading conditions. > This is why IBIS simulators can reproduce correct waveforms even > if the load is different from the Rfixture that was used when the > Vt curves were generated. > > I hope this will help you to understand this better. > > Arpad > ------------------------------------------------------------------ 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 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