Hi all, Thanks for the kind and insightful reply by Mickael Poimboeuf and Andrew Ingraham. I will do some more experiments and let you guys know how it went. Regards, Tim --- "Ingraham, Andrew" <a.ingraham@xxxxxxxx> wrote: > I like Michael Poimboeuf's answer. Good reply. > > To elaborate a bit more on the choice between wider > or narrower in your > second PLL... > > If you are very concerned about keeping the second > PLL from losing lock, > perhaps it should be wider than the first PLL. That > way it has a better > chance of tracking jitter and phase or frequency > changes that come down the > line from the slower first PLL. If you are paranoid > about cascading two > identical PLLs, this might be your better choice. > > On the other hand, it is not necessarily bad to > follow a PLL with one that > is narrower than the first. PLLs are often used to > clean up noisy (jittery) > signal sources. In this application a narrowband > PLL is very desirable. > You just need to have a handle on how much > worst-case jitter might be coming > from the first PLL, and do an analysis that the > second PLL doesn't lose lock > from it, and that your system can tolerate the phase > error due to the fact > that the second PLL is averaging the phase and not > tracking it. > > Regards, > Andy > > > I have a question on the one PLL driving > another > > PLL. I know that if both PLL has the same > bandwidth > > it is not a good idea. So my questions is what > should > > the 1st PLL bandwidth should be, should be be > narrow > > band and the 2nd PLL to be a wideband PLL? Or is > it > > the > > other way around? Is there any articles > discussion > > this > > issue. Thanks in advance. > > > ------------------------------------------------------------------ > 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 > > __________________________________ Do you Yahoo!? Yahoo! Movies - Buy advance tickets for 'Shrek 2' http://movies.yahoo.com/showtimes/movie?mid=1808405861 ------------------------------------------------------------------ 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