Copyright: 1996 - 2024
BSEE - KB3UON
RF Cafe began life in 1996 as "RF Tools" in an AOL screen name web space totaling
2 MB. Its primary purpose was to provide me with ready access to commonly needed
formulas and reference material while performing my work as an RF system and circuit
design engineer. The World Wide Web (Internet) was largely an unknown entity at
the time and bandwidth was a scarce commodity. Dial-up modems blazed along at 14.4 kbps
while tying up your telephone line, and a nice lady's voice announced "You've Got
Mail" when a new message arrived...
All trademarks, copyrights, patents, and other rights of ownership to images
and text used on the RF Cafe website are hereby acknowledged.
My Hobby Website:
Crystal Equivalent Circuit - RF Cafe Forums
RF Cafe Forums closed its virtual doors in 2012 mainly due to other social media
platforms dominating public commenting venues. RF Cafe Forums began sometime around
August of 2003 and was quite well-attended for many years. By 2010, Facebook and
Twitter were overwhelmingly dominating online personal interaction, and RF Cafe
Forums activity dropped off precipitously. If the folks at
phpBB would release a version with integrated
sign-in from the major social media platforms, I would resurrect the RF Cafe Forums,
but until then it is probably not worth the effort. Regardless, there are still
lots of great posts in the archive that ware worth looking at.
Below are the old forum threads, including responses to the original posts.
|-- Amateur Radio
Gripes & Humor
-- CAE, CAD, &
Test & Measurement
Post subject: Crystal Equivalent Circuit Posted:
Tue Jul 08, 2008 6:42 pm
Joined: Tue Feb
27, 2007 6:16 am
I wish to design and
simulate a crystal oscillator. I have been having great difficulty obtaining
typical crystal equivalent circuit values for whatever frequency.
Can anyone suggest a manufacturer that lists the equivalent
circuit values for each of their crystals?
Other than measuring
the values, is there an easier way of obtaining typical crystal equivalent
Darcy Randall, Perth, Western Australia
Post subject: Posted: Wed Jul 09, 2008 4:12 am
Joined: Fri Feb 17, 2006 12:07 pm
you will find the equivalent circuit and
much useful data on www.euroquartz.co.uk
Post subject: Posted: Wed Jul 09, 2008 11:40 am
Joined: Tue Jul 08, 2008 7:15 pm
Most manufacturers will specify Rm (series
resistance at resonance), Co (holder capacitance) and of course Fo,
so all you really need to complete basic model is either Cm, Lm or Q.
Frerking lists the following typical Qs:
200 KHz Fundamental
2 MHz Fundamental - 54e3
30 MHz 3rd Overtone - 1e5
90 MHz 5th Overtone - 85e3
Many manufacturers will allow
you to specify Cm or Lm, but this is not typically specified on data
sheet since it makes little difference for clock oscillator, where most
crystals are used, and it would add cost to actually measure it in manufacturing.
Hope this helps.
Post subject: Posted: Wed Jul 09, 2008 6:35 pm
Joined: Tue Feb 27, 2007 6:16 am
I have what I need. Cheers
Randall, Perth, Western Australia
subject: Posted: Thu Jul 10, 2008 3:41 pm
Joined: Mon Jun 27, 2005 2:02 pm
Try also Fox Elecctronics: http://www.foxonline.com/
They have detailed specifications for their crystals and good
application notres on their website. I had the sdame problem as you
and they helped me a lot.