66AK2E05: About Clock Input Electrical Data/Timing Unit Issue

Yimin,

Understanding the methods for converting from one jitter measurement type to another requires a good understanding of clock jitter.  There are conditions for these conversions.  If you are not well studies in these topics, I recommend that you use equipment that generates the outputs in the correct form.

There are application notes on this topic provided by companies the produce clock jitter measurement devices.  Below are links to a few references that I have found useful:

Teledyne Lecroy
Understanding Jitter Calculations: Why Dj Can Be Less Than DDj (or Pj)
teledynelecroy.com/.../understanding-dj-ddj-pj-jitter-calculations

SiTime
Clock Jitter Definitions and Measurement Methods
SiT-AN10007 Rev 1.2
www.sitime.com/.../AN10007-Jitter-and-measurement.pdf

Tom

Hi Sir

thanks for your help

According to the page#3 in doc AN10007.pdf your provided, we can calculate the value of ps-rms through the below link.

But it should be defined by Period Jitter....etc., not Tj. (TI doc的TJ = PJ?)

Could you help to check this?

BR

Yimin

Yimin,

We are not defining period jitter with this specification.  This specification is for RMS phase jitter since this is a reference clock for a SERDES PLL.  This is discussed in Section 2.4 of application note AN10007.  This needs to be bounded by frequency limits.  I beleive you should use 100KHz to 20MHz.

Tom

Yimin,

Do you have follow-up questions?  Otherwise we will close this thread.

Tom