ppm vs ps - diyAudio
Go Back   Home > Forums > Source & Line > Digital Source

Digital Source Digital Players and Recorders: CD , SACD , Tape, Memory Card, etc.

Please consider donating to help us continue to serve you.

Ads on/off / Custom Title / More PMs / More album space / Advanced printing & mass image saving
Reply
 
Thread Tools Search this Thread
Old 3rd August 2004, 01:19 AM   #1
nl is offline nl  United States
diyAudio Member
 
Join Date: Mar 2004
Location: New York
Default ppm vs ps

Looking at SMD clock crystals, they seemed to be spec'ed in "parts per million." How does this translate into picoseconds of jitter? Does anyone have a good off-the-rack SMD clock to recommend?
  Reply With Quote
Old 3rd August 2004, 04:02 AM   #2
BrianL is offline BrianL  United States
diyAudio Member
 
Join Date: Mar 2002
Location: USA
"ppm" is almost always the long term drift accuracy spec.
Sometimes the nominal frequency accuracy is spec'ed in
ppm.

This has little or nothing to do with jitter (related to phase noise which
is a more useful spec). Many grunt clock oscillators don't
spec phase noise and/or jitter.
__________________
bel
  Reply With Quote
Old 3rd August 2004, 04:03 AM   #3
Banned
 
Join Date: Feb 2002
Location: As far from the NOSsers as possible
Default You can't........

There is no relationship, at all, between accuracy (ppm) and jitter.

Anyone who tells you there is doesn't know squat about oscillators.

About jitter specs........of clocks........(crystals don't have "jitter" specs.)

They are often times misleading, as they always seem to neglect the frequency range of the jitter. Although close-in jitter is probably the most important, and would most likely be part of any jitter spec. But don't count on it.

Are you asking about crystals or clocks???

Jocko
  Reply With Quote

Reply


Hide this!Advertise here!
Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off



New To Site? Need Help?

All times are GMT. The time now is 12:48 AM.


vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2014 DragonByte Technologies Ltd.
Copyright 1999-2014 diyAudio

Content Relevant URLs by vBSEO 3.3.2