Mentor's Eldo can use all the normal linear noise analysis device specifications (flicker, thermal, junction, etc) in a transient analysis as described by this excerpt from the Eldo manual: Transient noise simulation can be applied to all types of circuit without restriction. To perform transient noise analysis, physical noise of electrical devices is emulated by time dependent current sources. The frequency characteristics of these sources are referred to the noise models of the noisy components. The method used is simple, fast and does not disturb the simulated behavior of the circuit because the noise signals introduced are continuous and fully deterministic. However last I'd heard, this was unique to Eldo with the other SPICE derivatives behaving as Ray described. =20 One could also incorporate any type of desired time-domain noise effect in IBIS 4.1 AMS models. =20 Gary -----Original Message----- From: si-list-bounce@xxxxxxxxxxxxx [mailto:si-list-bounce@xxxxxxxxxxxxx] On Behalf Of Ray Anderson Sent: Tuesday, August 23, 2005 1:34 PM To: james.plesa@xxxxxxx; scott@xxxxxxxxxxxxx; edpc108@xxxxxxxxx Cc: si-list@xxxxxxxxxxxxx; Ray Anderson Subject: [SI-LIST] Re: Accounting random jitter I always thought the .noise function in spice merely determined the total RMS noise contribution of the various circuit components (resistive and active) whose noise performance could either be calculated or was specified. It isn't obvious to me that this function can be used to inject jitter into a time domain simulation. Can spice's Monte Carlo statistical capabilities be applied to the zero crossings of a voltage source? I've always thought that it could only statistically vary component values. On the other hand one could probably generate a random noise voltage and sum it with a reference voltage in a comparator to cause random jitter on the output of the comparator. Alternatively, the random noise source could be used to modulate a behavioral VCO clock source. This basically emulates some techniques that can be applied to physical test equipment in the lab. -Ray -----Original Message----- From: si-list-bounce@xxxxxxxxxxxxx [mailto:si-list-bounce@xxxxxxxxxxxxx] On Behalf Of Plesa, James T. Sent: Tuesday, August 23, 2005 11:00 AM To: scott@xxxxxxxxxxxxx; edpc108@xxxxxxxxx Cc: si-list@xxxxxxxxxxxxx Subject: [SI-LIST] Re: Accounting random jitter Most or all SPICE simulators that I have used have included .NOISE analysis and Monte-Carlo analysis, either of which would seem suited to introducing eye-diagram jitter.=3D3D20 Jim Plesa Northrop Grumman Corp.=3D3D20 -----Original Message----- From: si-list-bounce@xxxxxxxxxxxxx [mailto:si-list-bounce@xxxxxxxxxxxxx] On Behalf Of Scott McMorrow Sent: Tuesday, August 23, 2005 12:45 PM To: edpc108@xxxxxxxxx Cc: si-list@xxxxxxxxxxxxx Subject: [SI-LIST] Re: Accounting random jitter Jayaprakash Unfortunately, no. SPICE is a deterministic simulator and does not simulate stochasic (random) processes. You will need something like Agilent ADS, Ansoft Designer, StatEye, or roll-your-own Matlab code to integrate random noise into your simulations.=3D3D20 regards, Scott Scott McMorrow Teraspeed Consulting Group LLC 121 North River Drive Narragansett, RI 02882 (401) 284-1827 Business (401) 284-1840 Fax http://www.teraspeed.com Teraspeed(r) is the registered service mark of Teraspeed Consulting Group LLC Jayaprakash wrote: >Hi, > > Is there a std. way to include/account random jitter effects in =3D a=3D3D20 >typical eye diagram simulation in SPICE? > > Thanks and regards, > Jayaprakash.=3D3D20 > > > =3D3D09 ------------------------------------------------------------------ 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