Steve, The board has many chips including ours and they all have different current requirement so it won't be correct to consider it equipotential and if I suppose consider them quasi-equipotential, what extra things I have to take care while generating s-parameter ?? OR do you mean to say for quasi-equipotential, separate vdd & gnd s-parameters will take care our problem ? Rajan On Wed, Jun 1, 2011 at 4:10 PM, steve weir <weirsi@xxxxxxxxxx> wrote: > You have a matrix of current sources attached to a matrix of RLCG legs, and > you want to know the noise voltage that occurs between different point pairs > in that matrix. If the product of the static and dynamic currents against a > section of those legs is very small, you can treat that region as a quasi- > equipotential. Otherwise you have to treat the point pairs as unique. > > Steve > > > On 6/1/2011 3:29 AM, Rajan Hansa wrote: > > Steve, > > > > You are right !! Our analog engineer basically wants to see ground > bounce w.r.t pcb ground which was not possible with single s-parameter but > you said that I have to do whole lot more than just produce s-parameters > between one port inside the package and some other virtual port. > > > Can you help me to understand that why separate s-parameter is not > sufficient to see ground bounce and what is the right way to handle such > problems ?? > > Rajan > > > On Wed, Jun 1, 2011 at 3:30 PM, steve weir <weirsi@xxxxxxxxxx> wrote: > >> What it sounds like your analog engineer wants is to be able to figure out >> how much bounce will occur in each plane relative to some external >> reference, such as the PCB Vss plane. In order to figure that out, you have >> to do a whole lot more than just produce s-parameters between one port >> inside the package and some other virtual port. Your analog engineer needs >> to be more specific about what he wants to figure out. >> >> Steve. >> >> >> On 6/1/2011 1:41 AM, Rajan Hansa wrote: >> >>> Guys, >>> I have got a request to provide sparameter for one package but this time >>> my >>> analog engineer wants seperate s-parameter for gnd& supply plane. The >>> reason he gave is that with single sparameter for vdd& gnd plane. He >>> can't >>> see gnd noise as s-parameter is generated with gnd as reference so it'll >>> always be seen as '0' but that problem won't come in separate >>> s-parameters >>> for gnd& supply planes. >>> >>> Though the tool I am using has an option to generate sparameter with >>> reference to some virtual point and I can use that option to generate >>> separate sparameters for gnd& supply but problem is that I have not >>> still >>> understood if using separate s-parameter is a right way to do things and >>> if >>> it's the standard practice in industry. >>> >>> Experts comments please. >>> >>> Rajan >>> >>> >>> ------------------------------------------------------------------ >>> 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 >> >> >> > > > -- > 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