I usually keep quiet on these but am puzzled if no one mentioned the via modeling and approximation section in=20 _High-Speed Signal Propagation_ by Johnson and Graham. Curt Curt McNamara. P.E.=20 Senior Electrical Engineer=20 Logic Product Development=20 411 Washington Ave. N Suite 101=20 Minneapolis, MN 55401=20 Tel 612-436-5178=20 Fax 612-672-0443=20 curtm@xxxxxxxxxxx=20 www.logicpd.com=20 This message (including any attachments) contains confidential information intended for a specific individual and purpose, and is protected by law. If you are not the intended recipient, you should delete this message and are hereby notified that any disclosure, copying, or distribution of this message, or the taking of any action based on it, is strictly prohibited. -----Original Message----- From: si-list-bounce@xxxxxxxxxxxxx [mailto:si-list-bounce@xxxxxxxxxxxxx] On Behalf Of dav0 Sent: Tuesday, July 19, 2005 10:37 AM To: si-list@xxxxxxxxxxxxx Subject: [SI-LIST] Re: SPAM: Score 3.9: Re: HSPICE and Via Modeling Thanks to everyone for the replies. I was mostly looking at extracting the capacitance and it may be the best thing to just do the math, though I have not seen too much in the way of formulae for capacitance of a via shaft penetrating a plane. Perhaps a good Physics book should be on the shopping list. Thanks Everyone! dav0 David Lieby Siemens Medical Solutions, Ultrasound Division, MVIS-S ?? wrote: > Hi,David > I think you don't need to consider the via impact under such low=20 > frequency. >=20 >=20 > > I have an engineer who wants a detailed model of a via. > > Mostly he is looking for capacitance. The part of the > > system he is working on runs at less than 5 MHz. The > > via is blind, with the closed end of the via ending > > fairly close to a ground plane. > > > > > > > > __ __ Top Pad > > ________ ][ _____ Reference layer > > ][ > > ---------][----- routing layer 1 > > ---------][----- routing layer 2 > > ________ ][ _____ Reference layer > > ][ > > ---------][----- routing layer 3 > > ---------][----- routing layer 4 > > ________ ][ _____ Reference layer > > ][ > > ---------][----- routing layer 5 > > ---------][----- routing layer 6 > > __][__ Bottom pad, end of via > > _________________ Reference layer, at center of stackup > > > > the same stackup reversed. > > > > My questions: > > 1. Can one analyze this in HSPICE? > > 2. Does anyone have a spice deck with anywhere near > > a starting point, that they can share. > > > > The vendor support engineer could not come up with > > anything helpful. > > > > Thanks, > > dav0 > > David Lieby > > Siemens Medical, USD, MVIS-S > > > > ------------------------------------------------------------------ > > To unsubscribe from si-list: > > si-list-request@xxxxxxxxxxxxx with 'unsubscribe' in the Subject=20 > 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 > > > > > > >=20 >=20 >=20 >=20 > = =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 > ???TOM,???????! <http://bjcgi.163.net/cgi-bin/newreg.cgi? > rf=3D050602> >=20 > ????????,???,?????????! > <http://bjcgi.163.net/cgi-bin/newreg.cgi? rf=3D050602> >=20 > ?????(http://sr.tom.com): ??? > <http://sr.tom.com/send.php?id=3D330&type=3D2> ???=20 > <http://sr.tom.com/send.php?id=3D315&type=3D2> ???=20 > <http://sr.tom.com/send.php?id=3D257&type=3D2> ??=20 > <http://sr.tom.com/send.php?id=3D247&type=3D2> ???????? >=20 > ???????(http://mm.tom.com/ivr/) : ????? > <http://fs.tom.com/sms/ivr_song_step0.php?=20 > var=3D1&id=3D37987&user_id=3D3&code_id=3Diw4001&> ????=20 > <http://fs.tom.com/sms/ivr_song_step0.php?=20 > var=3D1&id=3D38205&user_id=3D3&code_id=3Diw4001&> ??????=20 > <http://fs.tom.com/sms/ivr_song_step0.php?=20 > var=3D1&id=3D37938&user_id=3D3&code_id=3Dis0001&> ????????=20 > <http://fs.tom.com/sms/ivr_song_step0.php?=20 > var=3D1&id=3D1431&user_id=3D3&code_id=3Diw4001&> >=20 > ???????(http://mm.tom.com/cailing/): ??????? > <http://fs.tom.com/sms/cailing_step0.php?=20 > = var=3D1&id=3D462&songtype=3D1&user_id=3D3&code_id=3D000000&songprovince=3D= ??&> ?=20 > ?????? <http://fs.tom.com/sms/cailing_step0.php?=20 > = var=3D1&id=3D300&songtype=3D1&user_id=3D3&code_id=3D000000&songprovince=3D= ??&> ?=20 > ??? <http://fs.tom.com/sms/cailing_step0.php?=20 > = var=3D1&id=3D1345&songtype=3D0&user_id=3D3&code_id=3D&songprovince=3D??&>= ???=20 > ?? <http://fs.tom.com/sms/cailing_step0.php?=20 > = var=3D1&id=3D376&songtype=3D0&user_id=3D3&code_id=3D&songprovince=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 >=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