[SI-LIST] Re: jitter measurements on clock
- From: steve weir <weirsi@xxxxxxxxxx>
- To: prasad <hariprasad.palli@xxxxxxxxx>
- Date: Mon, 16 Aug 2010 06:06:42 -0700
Instantaneous phase error is a time varying quantity. Like any other
time varying quantity it can be processed through a frequency selective
filter to obtain specific results. Filter parameter selection depends
on the application requirements.
Steve.
prasad wrote:
> 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
>
>
>
>
--
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
Other related posts:
