Steve, Let me ask you to reconsider based on your own comments. IF the customer is asking for a more accurate package model from Intel, they would probably want all the node 0 connections to be in the PCB with Vdd and Vss connections somewhat like a signal, because, as you said below, using a node 0 connection in the package would short out real power distribution issues. There was some work in the mid 90s with simulation and measurement techniques where a temporary ground was used for peripheral leaded parts such that all pins were treated as signals which allowed a full matrix without the use of node 0. Look for stuff related to JEDEC JC-15. Also, there was some work and a paper by Bryan Young on the math to transform the inductance matrix from one with a temporary ground to one where the matrix was reduced by identifying specific pins as ground. But at the time, "single lump" models were sufficient. I think the technique for using a temporary ground for the package is still valid, but I haven't tested recently. Certainly the transform math gets way more complex when the phase difference across the package is no longer very small at the bandwidth frequency. Aubrey Sparkman 512-461-6165 asparky@xxxxxxxxxxxxxxxxxxxxxxxx -----Original Message----- From: si-list-bounce@xxxxxxxxxxxxx [mailto:si-list-bounce@xxxxxxxxxxxxx] On Behalf Of steve weir Sent: Tuesday, November 23, 2010 8:10 AM To: Haller, Motti Cc: si-list@xxxxxxxxxxxxx Subject: [SI-LIST] Re: Power delivery model with real GND ports ? I think the problem is with your customer's concept of ground. Your PDN is going to exhibit voltage drops from wherever you define your reference Vdd and Vss points. If you attach node 0 connections in more than one place you will in effect short out parts of your model and it will not report correct results. If you just want voltage measurements referenced to SPICE node 0 for convenience, insert E elements for those measurements. Steve Haller, Motti wrote: > Hi > Does anyone know how to create a power delivery model without losing the GND ports? > > My end user want to have the gnd/vss (in & out) ports not embedded as ref but as real ports. > > (can be touchstone / spice or RLGC). > > If I use this gnd source/sync port as ref. How does the gnd resistance and inductance reflects into the VCC* ports/nets. > > > Thanks > Motti > > --------------------------------------------------------------------- > Intel Israel (74) Limited > > This e-mail and any attachments may contain confidential material for > the sole use of the intended recipient(s). Any review or distribution > by others is strictly prohibited. If you are not the intended > recipient, please contact the sender and delete all copies. > > ------------------------------------------------------------------ > 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 technical documents are available at: > http://www.si-list.net > > List archives are viewable at: > //www.freelists.org/archives/si-list > > Old (prior to June 6, 2001) list archives are viewable at: > http://www.qsl.net/wb6tpu > > > > -- Steve Weir IPBLOX, LLC 150 N. Center St. #211 Reno, NV 89501 www.ipblox.com (775) 299-4236 Business (866) 675-4630 Toll-free (707) 780-1951 Fax ------------------------------------------------------------------ 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 technical documents are available at: http://www.si-list.net List archives are viewable at: //www.freelists.org/archives/si-list 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 technical documents are available at: http://www.si-list.net List archives are viewable at: //www.freelists.org/archives/si-list Old (prior to June 6, 2001) list archives are viewable at: http://www.qsl.net/wb6tpu