Dear All, Thanks for your valuable reply! Its really help me to solve some confusions. Once again, thanks for your time and consideration! Best Regards, Jayasuryan -----Original Message----- From: Lee Ritchey Sent: Saturday, January 07, 2012 4:51 AM To: Scott McMorrow ; si-list@xxxxxxxxxxxxx Subject: [SI-LIST] Re: Impedance Controlled Board Production Vs Normal Board Production Good reply! Lee -----Original Message----- >From: Scott McMorrow <scott@xxxxxxxxxxxxx> >Sent: Jan 6, 2012 6:45 AM >To: si-list@xxxxxxxxxxxxx >Subject: [SI-LIST] Re: Impedance Controlled Board Production Vs Normal >Board Production > >Did I just see an eye diagram in the sky? To the simulation cave .... > >Scott McMorrow >Grand Poobah > Teraspeed Consulting Group LLC >121 North River Drive >Narragansett, RI 02882 >(401) 284-1827 Business >(401) 284-1840 Fax > >http://www.teraspeed.com > >Teraspeed® is the registered service mark of >Teraspeed Consulting Group LLC > > >On 1/6/2012 3:44 AM, Tom Dagostino wrote: >> This is a job for Simulation Man. >> >> One needs to look at the spec for any particular application and >> determine >> through analysis what the tolerance can/should be. There is no rule of >> thumb that works. >> >> Tom Dagostino >> >> Teraspeed Labs >> 9999 SW Wilshire St. >> Suite 102 >> Portland, OR 97225 >> USA >> >> 971-279-5325 Office >> 971-279-5326 FAX >> 503-430-1065 Cell >> >> tom@xxxxxxxxxxxxx >> www.teraspeed.com >> >> Teraspeed Consulting Group LLC >> 121 North River Drive >> Narragansett, RI 02882 >> 401-284-1827 >> >> >> -----Original Message----- >> From: si-list-bounce@xxxxxxxxxxxxx [mailto:si-list-bounce@xxxxxxxxxxxxx] >> On >> Behalf Of Rajan Hansa >> Sent: Thursday, January 05, 2012 11:46 PM >> To: si-list@xxxxxxxxxxxxx >> Cc: David Siadat (dsiadat) >> Subject: [SI-LIST] Re: Impedance Controlled Board Production Vs Normal >> Board >> Production >> >> guys don't you think that if impedance variation is under 10 % then we >> shouldn't worry much about it. >> My analogy is that for 10 % impedance variation return loss is more than >> -20 db and effect of this return loss is less than 0.5 db on insertion >> loss >> which is quite acceptable when we compare it with losses due to >> attenuation >> on insertion loss. >> >> Correct me if i am wrong or am I missing something ??? >> >> >> On Fri, Jan 6, 2012 at 3:51 AM, David Siadat (dsiadat) >> <dsiadat@xxxxxxxxx>wrote: >> >>> I agree with Aubrey's statement. >>> If you do not specify Impedance Control design (possibly for each >>> layer), then traces on the layer with not enough copper material will >>> have more than +/-10% impedance variations even if you specified its >>> characteristic impedance in your request! >>> >>> -David >>> >>> -----Original Message----- >>> From: si-list-bounce@xxxxxxxxxxxxx >>> [mailto:si-list-bounce@xxxxxxxxxxxxx] >>> On Behalf Of Aubrey K Sparkman >>> Sent: Thursday, January 05, 2012 11:49 AM >>> To: Michael Greim >>> Cc: Ken Cantrell; Mikhail Matusov; si-list@xxxxxxxxxxxxx >>> Subject: [SI-LIST] Re: Impedance Controlled Board Production Vs Normal >>> Board Production >>> >>> Michael, >>> >>> A fab house only has to meet the specifications in the contract. I >>> would say the company got what they specified. >>> >>> My point was that an impedance only specification is often inadequate. >>> >>> >>> Aubrey >>> >>> On 1/5/12 1:16 PM, "Michael Greim"<mgreim001@xxxxxxxxx> wrote: >>> >>>> There needs to be an interlock between the fab house and design team. >>>> If different construction methods are employed and they aren't >>>> checked then offending engineer is really getting what they deserve. >>>> Check twice, or more, and cut once is a lesson often learned quite >>>> painfully. >>>> -Michael >>>> >>>> On Thu, Jan 5, 2012 at 10:27 AM, Aubrey K Sparkman< >>>> asparky@xxxxxxxxxxxxxxxxxxxxxxxx> wrote: >>>> >>>>> Ken, >>>>> >>>>> What you say is true. What hasn't been mentioned is the risk behind >>>>> specifying only the impedance. >>>>> >>>>> Mikhail makes a good point about specifying the board stackup >>>>> CONSTRUCTION. I have seen failures when impedance only was >>> specified. >>>>> The design went out as a dual stripline with 4 mil cores between >>>>> the signals and their respective reference planes and a 12 mil >>>>> prepreg between the two signal layers. The pcb house was given >>>>> permission to use 5 >>> mil >>>>> cores since they didn't have 4 mil cores in stock. For the 2nd >>> build, >>>>> the >>>>> pcb house outsourced the design to another house which used 8 mil >>> cores. >>>>> Trace widths and prepreg thickness were adjusted appropriately so >>> that >>>>> both board thickness and impedance specifications were met. >>>>> >>>>> Any guesses about the performance of the boards in the 2nd build? >>>>> >>>>> Aubrey Sparkman >>>>> SparkRight Solutions >>>>> >>>>> On 1/5/12 10:36 AM, "Ken Cantrell"<Ken.Cantrell@xxxxxxxxxxxxxxxx> >>>>> wrote: >>>>> >>>>>> Mikhail, >>>>>> I'm not disputing anything that you said, just pointing out that: >>>>>> "If I, as a designer, know the process and materials used by the >>>>>> particular manufacturer well enough" is a big If. That's a mature >>>>>> designer talking. Not something a relative beginner would know or >>>>>> even be able to accomplish. >>>>>> >>>>>> 2cents >>>>>> Ken >>>>>> >>>>>> -----Original Message----- >>>>>> From: si-list-bounce@xxxxxxxxxxxxx >>>>>> [mailto:si-list-bounce@xxxxxxxxxxxxx]On Behalf Of Mikhail Matusov >>>>>> Sent: Thursday, January 05, 2012 9:05 AM >>>>>> To: si-list@xxxxxxxxxxxxx >>>>>> Subject: [SI-LIST] Re: Impedance Controlled Board Production Vs >>> Normal >>>>>> Board Production >>>>>> >>>>>> >>>>>> I don't think those who responded understood the question correctly. >>> I >>>>>> think >>>>>> the OP was asking whether some degree of impedance control can be >>>>> achieved >>>>>> by precisely specifying the board's stackup, width of the traces, >>> and >>>>>> process tolerances without explicitly asking the manufacturer to >>>>> control >>>>>> impedance. For some applications it just boils down to the cost. >>>>>> If >>> I, >>>>> as >>>>>> a >>>>>> designer, know the process and materials used by the particular >>>>>> manufacturer well enough I should be able to specify the board in >>>>>> such a way that >>>>> the >>>>>> impedance will end up in the right ballpark. In fact, I use this >>>>> method >>>>>> for >>>>>> non-critical designs. >>>>>> >>>>>> ======================= >>>>>> Mikhail Matusov >>>>>> Senior Hardware Design Engineer >>>>>> Square Peg Communications >>>>>> Tel.: +1 (613) 271-0044 ext.231 >>>>>> Fax: +1 (613) 271-3007 >>>>>> http://www.squarepeg.ca >>>>>> >>>>>> >>>>>> >>>>>> >>>>>> >>>>>> >>>>>> ----- Original Message ----- >>>>>> From: "Loyer, Jeff"<jeff.loyer@xxxxxxxxx> >>>>>> To:<si-list@xxxxxxxxxxxxx> >>>>>> Sent: Thursday, January 05, 2012 10:22 AM >>>>>> Subject: [SI-LIST] Re: Impedance Controlled Board Production Vs >>> Normal >>>>>> Board >>>>>> Production >>>>>> >>>>>> >>>>>>> Perhaps I'm the only one who is finding it ironic that, on a >>> "Signal >>>>>>> Integrity" reflector list, "Impedance Controlled" isn't >>>>>>> considered "Normal". I haven't had the luxury of not specifying >>>>>>> impedance >>>>> control >>>>>>> since a small 33MHz PCI card design, many years ago. >>>>>>> >>>>>>> I'm afraid Jayasuryan that you won't find the answer you're >>> looking >>>>> for >>>>>>> on >>>>>>> an e-mail thread, or it is going to be a long, drawn out, >>>>>>> painful affair. >>>>>>> You have a lot of work to do to understand what impedance >>>>>>> control >>> is >>>>> and >>>>>>> how it relates to signal integrity. I would recommend starting >>> with >>>>> the >>>>>>> books that have been listed many times on this list. You can >>>>>>> also search the archives for "impedance control" to find >>>>>>> discussions about >>>>> different >>>>>>> opinions on how much is enough. >>>>>>> >>>>>>> Good luck in the new year, >>>>>>> Jeff Loyer >>>>>>> >>>>>>> -----Original Message----- >>>>>>> From: si-list-bounce@xxxxxxxxxxxxx >>>>> [mailto:si-list-bounce@xxxxxxxxxxxxx >>>>> ] >>>>>>> On Behalf Of steve weir >>>>>>> Sent: Monday, January 02, 2012 6:23 AM >>>>>>> To: si-list@xxxxxxxxxxxxx >>>>>>> Subject: [SI-LIST] Re: Impedance Controlled Board Production Vs >>>>> Normal >>>>>>> Board Production >>>>>>> >>>>>>> Suppose as you like. Hope as you might. What you don't >>>>>>> contract >>> is >>>>> not >>>>>>> guaranteed. >>>>>>> >>>>>>> Steve. >>>>>>> On 1/2/2012 5:56 AM, Jayasuryan KG wrote: >>>>>>>> Dear Experts, >>>>>>>> >>>>>>>> >>>>>>>> >>>>>>>> Happy New Year!! >>>>>>>> >>>>>>>> >>>>>>>> >>>>>>>> I have question regarding the impedance controlled board >>> production! >>>>>>>> Is there any special process to produce impedance controlled >>> board >>>>>>>> rather than the normal production? >>>>>>>> >>>>>>>> >>>>>>>> >>>>>>>> Suppose if I go with normal production for a impedance >>> controlled >>>>>>>> board >>>>>>>> (the design has been done to meet the impedance) what are the >>>>> possible >>>>>>>> issues can happen? >>>>>>>> >>>>>>>> >>>>>>>> >>>>>>>> Looking for your immediate response. Thanks in advance. >>>>>>>> >>>>>>>> >>>>>>>> >>>>>>>> Best Regards, >>>>>>>> >>>>>>>> - Jayasuryan >>>>>>>> >>>>>>>> >>> ------------------------------------------------------------------ >>>>>>>> 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 >>>>>>> >>>>>>> All contents Copyright (c)2012 IPBLOX, LLC. All Rights Reserved. >>>>>>> This e-mail may contain confidential material. >>>>>>> If you are not the intended recipient, please destroy all >>>>>>> records >>> and >>>>>>> notify the sender. >>>>>>> >>>>>>> ---------------------------------------------------------------- >>>>>>> -- >>>>>>> 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 >>>>>>> >>>>>>> >>>>>>> >>>>>> ------------------------------------------------------------------ >>>>>> 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 >>>>>> >>>>>> >>>>>> >>>>> >>>>> ------------------------------------------------------------------ >>>>> 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 >>>>> >>>>> >>>>> >>>> >>>> -- >>>> -Michael. >>>> >>>> We will either find a way or make one - Hannibal >>>> >>>> In the middle of every difficulty lies opportunity - Al Einstein >>>> >>>> If you think you can do something or you think >>>> you can't, in both cases you are probably right - H Ford >>>> >>>> If you're not getting the results you want with the current approach, >>>> move on and try something else. - A. Fleischmann >>>> >>>> >>>> ------------------------------------------------------------------ >>>> 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 >>> >>> >>> ------------------------------------------------------------------ >>> 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 >> >> >> ------------------------------------------------------------------ >> 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 > > ------------------------------------------------------------------ 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