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Topic: Whats the capacitance of a sm pad? (Read 587 times) previous topic - next topic

jonisonvespaa

hi,
im building something and want to try a resignator and crystal in the same circuit, ive added a pad so i can fit both obviously not at the same time, just wondering if the surface mount pad will effect the resignator/ timing because of the pads?

cheers

dhenry

Quote
a resignator


What's that?

Quote
if the surface mount pad will effect the resignator/ timing because of the pads?


Yes.

JoeN

Pretty sure he means resonator, probably a ceramic.  You want both just as an experiment?  I've never used those things, they have bad reputation for accuracy and crystals are dirt cheap anyway, why not use a crystal?
I have only come here seeking knowledge. Things they would not teach me of in college.

dc42


im building something and want to try a resignator and crystal in the same circuit, ive added a pad so i can fit both obviously not at the same time, just wondering if the surface mount pad will effect the resignator/ timing because of the pads?


In principle, yes (especially if there is a ground plane on the other side of the board); but the effect will be very small, so no need to worry about it.
Formal verification of safety-critical software, software development, and electronic design and prototyping. See http://www.eschertech.com. Please do not ask for unpaid help via PM, use the forum.

oric_dan

I think there might be more of a problem with the capacitor pads being shorted out by the
metal crystal case, since there's hardly any spacing between the two. 

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