Hi, I have some nets in a ten layer board, his types is SerDes 125 MHZ differentials pairs, from Marvell 88E1111 to an SFP Module. The SFP Module is powered from 2.5V and SFP Module =E9 powered from 3.3 V. What the power plane I must considerate to the reference this traces? 3.3V or 2.5V? Best Regards. =20 Jarbas Aryel Nunes da Silveira, PMP engenheiro eletricista Fone: +55 (85) 3216.7916 Fax: +55 (85) 3216.7864 Skype: jarbas.aryel MSN: jarbas@xxxxxxxxxxxxxxxx =20 ISO 9001: 2000 - CMMI3 www.atlantico.com.br =20 =20 =20 =20 =20 =20 =20 =20 =20 =20 =20 =20 =20 -----Mensagem original----- De: si-list-bounce@xxxxxxxxxxxxx [mailto:si-list-bounce@xxxxxxxxxxxxx] Em nome de olaney@xxxxxxxx Enviada em: quinta-feira, 7 de junho de 2007 20:41 Para: ron@xxxxxxxxxxx Cc: si-list@xxxxxxxxxxxxx Assunto: [SI-LIST] Re: USB cable model This is a very big hammer to solve what should not be a very big problem. Adherence to spec is the bedrock of this design. Stock USB 2.0 rated cable applied in the recommended way should get you there. If not, then a TDR can help find where the spec is violated, and that will be either where the cable meets the connector, where the mating connector meets the PCB traces, the traces themselves (most likely), or where the traces meet the chip or passive components (next most likely). TDT should be used in conjunction with TDR, because a cable with high attenuation can look good on TDR, yet fail to deliver proper TDT waveforms. Is more than the spec rated distance contemplated? Will these not be off-the-shelf cables? If there is nothing special about this design, nothing above and beyond recommended practices should be required for implementation. Orin On Thu, 07 Jun 2007 16:06:49 -0700 ronald miller <ron@xxxxxxxxxxx> writes: > Hi >=20 > A two day task using a TDR(Tek), convert data to ADS and build a=20 > transmission line equivalent model > in ADS which then can be used for simulating anything you want. =20 > The=20 > mdel can be converted to spice > but the accuracy gets worse because frequency dependent factors are=20 > masked. >=20 > Ron >=20 > mukul pingley wrote: >=20 > >Hi All, > > I have below query, it would be greatly > >appreciated if you can provide me with some info. on > >this. =20 > > Is it possible to generate a model for USB? Is > >there any the equivalent electrical model of USB cable > >model for USB2.0 transceiver? If not, > >is it possible to generate a model for USB cable for > >stimulating standing wave phenonmena such as > >reflected-wave effect, bounce back effect, propogation > >delay, eye diagram and jitter in any spice simulator? > > > >Thanks, > >Mukul > > > > > > > > =20 > ________________________________________________________________________ _ ___________ > >Park yourself in front of a world of choices in alternative=20 > vehicles. Visit the Yahoo! Auto Green Center. > >http://autos.yahoo.com/green_center/=20 > >------------------------------------------------------------------ > >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 technical documents are available at: > > http://www.si-list.net > > > >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 > > > > > > =20 > > >=20 > --=20 > Ronald Miller > Ghz Data, Signal Integrity Consulting > 7721 Sunset Ave. > Newark CA 94560 > tel 510-793-4744 > cell 510-377-9380 > fax 510-742-6686 > www.ghzdata.com >=20 > ------------------------------------------------------------------ > To unsubscribe from si-list: > si-list-request@xxxxxxxxxxxxx with 'unsubscribe' in the Subject=20 > field >=20 > or to administer your membership from a web page, go to: > //www.freelists.org/webpage/si-list >=20 > For help: > si-list-request@xxxxxxxxxxxxx with 'help' in the Subject field >=20 >=20 > List technical documents are available at: > http://www.si-list.net >=20 > 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 >=20 >=20 >=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 technical documents are available at: http://www.si-list.net 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 The attachment named could not be scanned for viruses because it is a password protected file. ------------------------------------------------------------------ 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 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