Joseph Could you tell me how long is the signal trace? In our PCB, there is also a simular case that a crystal is driving three load. Best Regards Zhangkun 2005.6.29 ----- Original Message ----- From: "Joseph Wang" <JYWANG@xxxxxxxxxx> To: <Rohan.Hubli@xxxxxxxxxxxxxxxx>; <ray.anderson@xxxxxxxxxx> Cc: <si-list@xxxxxxxxxxxxx> Sent: Wednesday, June 29, 2005 6:02 AM Subject: [SI-LIST] Re: Single crystal driving two different inputs of a chip > 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