Bad idea. What you should do is use one oscillator to generate a reference that you then distribute. Steve. At 03:10 PM 6/28/2005 -0700, Rohan Hubli wrote: >Sorry for the confusion what i meant is connecting a single crystal = >resonator to two >oscillators within a chip > >Hope that clarifies my question=20 > >-----Original Message----- >From: Joseph Wang [mailto:JYWANG@xxxxxxxxxx] >Sent: Tuesday, June 28, 2005 3:02 PM >To: Rohan Hubli; ray.anderson@xxxxxxxxxx >Cc: si-list@xxxxxxxxxxxxx >Subject: RE: [SI-LIST] Re: Single crystal driving two different inputs >of a chip=20 > > >Should not be a problem. In my previous board design, we connect four >clock inputs together to a signal oscillator, running 33MHz. > >Well, you have to know what you are doing. In rare case, the oscillator >has very weaker drive strength. The clock inputs pins on the chip >should be close enough, not to rise up SI issue, etc. > >Anyway, the concern about the jitter is too pessimistic to me. Any >reason why and failing case? > >Regards, >Joseph Wang > > >-----Original Message----- >From: si-list-bounce@xxxxxxxxxxxxx [mailto:si-list-bounce@xxxxxxxxxxxxx] >On Behalf Of Rohan Hubli >Sent: Tuesday, June 28, 2005 2:46 PM >To: ray.anderson@xxxxxxxxxx >Cc: si-list@xxxxxxxxxxxxx >Subject: [SI-LIST] Re: Single crystal driving two different inputs of a >chip=20 > >I am talking about onnecting a single quartz >oscillator to two clock inputs > >-----Original Message----- >From: Ray Anderson [mailto:ray.anderson@xxxxxxxxxx] >Sent: Tuesday, June 28, 2005 2:42 PM >To: si-list@xxxxxxxxxxxxx >Cc: Ray Anderson >Subject: [SI-LIST] Re: Single crystal driving two different inputs of a >chip=3D20 > > >Are you asking about connecting a single crystal resonator to two >oscillators within a chip (I hope not...) or connecting a single quartz >oscillator to two clock inputs? > >-Ray > > >-----Original Message----- >From: si-list-bounce@xxxxxxxxxxxxx [mailto:si-list-bounce@xxxxxxxxxxxxx] >On Behalf Of Rohan Hubli >Sent: Tuesday, June 28, 2005 2:38 PM >To: si-list@xxxxxxxxxxxxx >Subject: [SI-LIST] Single crystal driving two different inputs of a chip > > >Folks,=3D3D3D20 > >Can a single crystal be driving two different inputs of a chip that feed >=3D3D3D >into=3D3D3D20 >two sensitive analog blocks within a chip. Has anyone had any experience >=3D3D3D > >doing this kind of a thing on the board ?=3D3D3D20 > >We are facing an issue where a 27Mhz crystal clock needs to be hooked up >=3D3D3D >to drive=3D3D3D20 >two sensitive analog cores.=3D3D3D20 > >If we make the connection internal to the chip then the jitter due to = >=3D >=3D3D >=3D3D3D >(trace delay + buffer delay + process variations)=3D3D3D20 >has significant impact on the audio quality. > >Not to mention the fact that any issues that surface and subsequent =3D >=3D3D3D >fixes with this approach will have significant=3D3D3D20 >respin costs for the chip.=3D3D3D20 > >Your inputs would be greatly appreciated.=3D3D3D20 > >Thanks >Rohan=3D3D3D20 >------------------------------------------------------------------ >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: =3D3D20 > //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 > =3D3D20 > > > >------------------------------------------------------------------ >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: =3D20 > //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 > =3D20 > >------------------------------------------------------------------ >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: =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 > > > >------------------------------------------------------------------ >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