At 07:43 PM 5/18/2005 -0400, you wrote:
>Charles Craft wrote:
>>If the pin spacing of a crystal matches the outer pins of a ceramic
>>resonator then adding the PTH for the center ground pin on the
>>resonators sounds like a pretty cool solution.
>
>OK, I'll have to look into that.  I've never used a resonator myself.  I
>guess I just haven't run into any high volume designs that needed pretty
>good but not really accurate PIC frequency.

They're great if you need reliable serial communication, and other timing
is okay to within +/-0.5% or so. You can use the same 3-pin pattern for a
HC-49/U crystal or a resonator and you'll have all three options-- crystal,
two-pin resonator (I have not used those ones), three-pin resonator.

Some crystals have a ground pin in the middle anyway (I've ordered them
that way for high EMI industrial situations), so using the three-pin
pattern makes sense (the middle wire is just welded to the housing)

>By the way, what's a "PTH"?

Plated through hole, I'd assume.

Best regards,

Spehro Pefhany --"it's the network..."            "The Journey is the reward"
speff@interlog.com             Info for manufacturers: http://www.trexon.com
Embedded software/hardware/analog  Info for designers:  http://www.speff.com




-- 
http://www.piclist.com PIC/SX FAQ & list archive
View/change your membership options at
http://mailman.mit.edu/mailman/listinfo/piclist