[SI-LIST] Re: jitter measurements on clock
- From: prasad <hariprasad.palli@xxxxxxxxx>
- To: si-list@xxxxxxxxxxxxx
- Date: Mon, 16 Aug 2010 18:05:55 +0530
hi All,
what is a "TIE filter" in the jitter measurement application? and how does
it affect measurements?
thanks,
hari prasad
On 14 August 2010 06:15, Chris Cheng <Chris.Cheng@xxxxxxxx> wrote:
> I agree we need to be careful about interpreting Rj data from scope
> software such as EzJIT.
> Chances are your clock source is generated from a PLL and your receiving
> chip is also a PLL.
> You need to at least input your receiving PLL loop bandwidth to EzJIT type
> of software.
> Jitter transfer is a function of your PLL loop bandwidth and the effective
> Rj after passing the ideal PLL is also dependent on the loop bandwidth.
> And if your receiver PLL bandwidth dropped below the reference clock PLL
> loop bandwidth, the Tj together with your Pj will grow.
> Chris
>
> -----Original Message-----
> From: si-list-bounce@xxxxxxxxxxxxx [mailto:si-list-bounce@xxxxxxxxxxxxx]
> On Behalf Of steve weir
> Sent: Thursday, August 12, 2010 1:40 PM
> To: prasad
> Cc: si-list@xxxxxxxxxxxxx
> Subject: [SI-LIST] Re: jitter measurements on clock
>
> Prasad, what you do depends on what you want to know. Before worrying
> so much about which buttons to push in the software, I think you need to
> clearly establish your goals.
>
> Do you want to know if the clock really meets its specification? Then
> you need to reproduce equivalent test conditions and measurement
> extraction as used by the clock manufacturer.
>
> Do you want to inspect incoming parts? Then you can less rigorous
> testing and extraction.
>
> Do you want to compare clocks from different manufacturers to make
> product selection? Then you need to not only test to the vendor spec,
> but qualify the clock under the conditions you wish to apply it.
>
>
> Steve.
> prasad wrote:
> > hi all,
> > thank you very much for your suggestions.
> >
> > from all the discussions , what i understand is ,
> >
> > 1.clock signal is assumed to have very negligible determinsitc jitter
> > 2. Manufacturers always specify the RJ of the same
> >
> >
> > if i need to verify this spec , i need to measure the TIE RMS (AC) or
> use
> > the RJ and DJ separation wizard to extract the RJ value verify.
> >
> >
> > please comment.
> >
> >
> > once again thank you very much for all your inputs.
> >
> >
> > Best Regards,
> > hari.
> >
> > On 13 August 2010 00:02, T.K. Jeon <tkjeon@xxxxxxxxxxx> wrote:
> >
> >
> >> Hi Hari,
> >>
> >> Simply taking the rms value of TIE won't give you random jitter. For
> better
> >> measurement, you should subtract the average TIE from your real time
> TIE,
> >> and take AC rms value of the resulted value. This would give you more
> >> accurate value than the rms of the real time TIE. However, the final
> value
> >> by using this way is not pure random jitter, i.e. it includes RJ plus
> >> uncorrelated PJ. Therefore, you should use other technique to separate
> the
> >> PJ component from your TIE measurement.
> >>
> >> Regards,
> >> TK
> >>
> >> -----Original Message-----
> >> From: si-list-bounce@xxxxxxxxxxxxx [mailto:si-list-bounce@xxxxxxxxxxxxx
> ]
> >> On Behalf Of prasad
> >> Sent: Wednesday, August 11, 2010 10:34 AM
> >> To: si-list@xxxxxxxxxxxxx
> >> Subject: [SI-LIST] jitter measurements on clock
> >>
> >> hi All,
> >> normally when we look at the data sheets of a clock signal for the
> jitter
> >> number, they usually specify it a RMS jitter.
> >>
> >> i understand from the basics that , only random jitter is quantified as
> >> RMS.
> >> i am not sure why there is only random jitter in the clock. is the
> >> Deterministic component is negligible?
> >>
> >> in that case, using our EzJIT plus software, if i want to measure this
> spec
> >> of a the clock, what would be my measurement?
> >>
> >> is it ok, if i measure the TIE of the clock and take the RMS of the TIE
> >> trend?
> >>
> >>
> >> thanks,
> >> hari
> >>
> >>
> >> ------------------------------------------------------------------
> >> 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
> >
> >
> >
> >
>
>
> --
> 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
>
>
> ------------------------------------------------------------------
> 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
>
>
>
> This email and any attachments thereto may contain private, confidential,
> and privileged material for the sole use of the intended recipient. Any
> review, copying, or distribution of this email (or any attachments) by
> others is strictly prohibited. If you are not the intended recipient, please
> contact the sender immediately and permanently delete the original and any
> copies of this email and any attachments thereto.
>
------------------------------------------------------------------
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
Other related posts:
