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Resonators or Crystals
Posted: Sat May 09, 2009 12:07 am
by Ron
Hi,
I have designed a small PIC board and have chosen a resonator with built in CAPs.
Here is the resonator I have chosen to use, I think the data sheet states +/- .3% Freq Stability
http://www.abracon.com/Resonators/awcr.pdf
Are typical crystals more accurate?
Thanks
Ron
Re: Resonators or Crystals
Posted: Mon May 11, 2009 8:20 am
by Benj
Hello Ron
A standard crystal will have an accuracy of +/- 20ppm or 0.002% , resonators are much less accurate in general.
Re: Resonators or Crystals
Posted: Sun May 17, 2009 9:36 am
by Ron
Hi,
OK, so I want to use a crystal, what type of caps are required?
Will these work
http://www.mouser.com/Search/Refine.asp ... 180J-TB-RC
The crystals I want to user are
http://www.mouser.com/Search/ProductDet ... 9Z2EojU%3d
Thanks
Ron
Re: Resonators or Crystals
Posted: Mon May 18, 2009 8:50 am
by Benj
Hello
I normally use a value of 22pF but im sure the 18pF caps there will work fine. Your crystals look fine.
Re: Resonators or Crystals
Posted: Tue May 19, 2009 12:05 pm
by Ron
Hi,
I will check to see if I can get this cap in a 22pf version.
Thank you,
Ron
Re: Resonators or Crystals
Posted: Sat May 23, 2009 8:16 pm
by Ron
Hi Ben,
How accurate are the internal OSC on the newer PICs, 16F887, 18F2620? I could not locate anything regarding this ini the datasheets.
Thanks
Ron
Re: Resonators or Crystals
Posted: Sun May 24, 2009 7:38 am
by Dan81
you can find this data page 256 (or 257) for the 16F887
Daniel