Hello All, I have a board with 2 sets of signal, the first set of nets need to be at 50ohm characteristic impedance and the other at 130ohm (single ended). This is not practically possible due to manufacturing constrains. Can you suggest me some technique so i can archive this on the board. Board details are as fallows: No. of Layers: 6 Stackup: top, ground, signal, signal, power, bottom Board thickness is 1.6mm Regards, S A Prasad +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ This e-mail is intended for the use of the individual or entity named above and may contain information that is confidential and privileged. If you are not the intended recipient, you are hereby notified that any dissemination, distribution or copying of this e-mail is strictly prohibited.If you have received this e-mail in error, please notify us immediately at prasadsa@xxxxxxxxxx and destroy the original message. While this e-mail and any attachments have been scanned for common computer viruses and found to be virus free, we recommend you also perform your own virus checking processes before opening any attachments. +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ ----- Original Message ----- From: "sghsu55" <sghsu55@xxxxxxxxxxxx> To: <John@xxxxxxxxxxxx>; <si-list@xxxxxxxxxxxxx> Sent: Wednesday, June 02, 2004 2:54 PM Subject: [SI-LIST] Re: Power plane resonace for multi-plane issues > > John, > > We have ever conducted lots of simulation and > measurement for the > similiar PDS structure as you described. In our > experiences, SpeedXP > can got quite accurate results with VNA measurement. > Especially, the > prediction of resonance frequency of PDS plane pair. > The results of > SpeedXP were slightly greater than measured as well > may come from the > fringing effect in the edge of plane. I don't have > sufficient > information to understand your case and simulation > setting. However, > in my opinion, I don't think that the overlap between > VCCP and VCC3_3 > is a good design. > > Best regards, > > Sogo Hsu Ph. D. > > Foxconn > > --- John Lin (aL��A�P��) <John@xxxxxxxxxxxx> ao�XTR��!G> > Dear all SI gurus, > > one question regarding Power plane resonance. > > Currently, I use SpeedXP from Sigrity for simulating > > power plane resonance. > > The set up is that > > TOP layer : VCCP > > ----- on top layer, > > 2nd layer : GND, VCC3_3 -- > > partially overlap both plane on the second layer > > 3rd layer : GND > > .... > > BOT layer: VCCP -- > > on bottom layer > > > > I inject a current pulse into VCCP at a node on the > > top layer. With Fourier transfer for voltage and > > current, and got a plot of plane impedance. My VNA > > measurement shows a resonance at 50 Mhz, but the > > simulation show 100Mhz. > > I think the mismatch may be among , VCCP,VCC3_3, and > > GND plane . Shall I let VCC3_3 plane float or tie > > it to somewhere? > > > > I know Cadence's PI tool need to specified each > > overlapping plane pairs with correct voltage > > difference for multi-plane issues. > > > > I don't know how to take care current injection > > issues on Sigrity SpeedXP for multi-planes. > > > > Does somebody please kindly shed some light on it. > > > > Thanks, > > John > > > > > > ----------------------------------------------------------------- > ��Uan�Mo!I!IEmail3B3B|?!I > ��K?O?U�MuYahoo!c_?�¡�?R||C > http://tw.companion.yahoo.com/ > ------------------------------------------------------------------ > 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