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 =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D -----Original Message----- From: adeel.ahmad@xxxxxx [mailto:adeel.ahmad@xxxxxx] Sent: Sunday, January 26, 2003 10:54 PM To: si-list@xxxxxxxxxxxxx Cc: Muranyi, Arpad Subject: [SI-LIST] Re: Question on IBIS: rising/falling waveform - How complete waveform created? hello Arpad, having gone through all the replies to my question on SI-list regarding IBIS V-t curves and having read the 2 IEEE papers referred by Herbert, i hope i have understood how and what information the V-I and V-t curves carry with them.The next step is how the simulator interprets it for simulations. And i am trying to figure out how the IBIS models allow simulations for loads other than the R_fixture as you said "waveform will adjust to the loading conditions"(and it should do that). If i have rightly = understood, it is the "Transient V-I curves" and the load line intersections that allow this. But for getting Transient V-I curves, alpba and beta values are required. One of the IEEE papers quoted by Herbert says "each set of alpha and = beta provides an instantaneous I/V curve for upper and lower devices of the buffer." Obtaining one complete Transient V-I curve(say,for time=3Dt1) = from a single alpba and beta is, i suppose, by scaling the dc V-I curve proportionally by factor of alpha and beta. Now with transient V-I curves available, for different loads, new waveform is obtained by plotting voltages(against time) at which each transient curve is intersected by the load line. i am unsure if thats the way things happen. so do comment. regards ADEEL ------------------------------------------------------------------ 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: =20 //www.freelists.org/archives/si-list or at our remote archives: http://groups.yahoo.com/group/si-list/messages=20 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 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