[sdiy] A little help regarding control crystals

[Seb Francis]

Seb Francis wrote:
> Altitude wrote:
>> http://www.mouser.com/search/ProductDetail.aspx?R=520-HCU400-SX
>>
>> I am not sure if this is what I should be using since the load caps are
>> designated as 10 pF instead of the 22 pF on the print.  Any advice or 
>> online
>> references would be greatly appreciated since I’m fairly new to
>> microprocessor based circuits.
>>   
>
>
> I expect it will work fine - if it doesn't oscillate reliably you can 
> play with the values of the 2 capacitors until it does. I always use 
> crystals rated 30pF for PICs, but this is not by choice - only because 
> it's how the easily available, cheap crystals come from my regular 
> supplier. When I'm building on solderless breadboard I sometimes have 
> to use smaller caps than specified (e.g. 15pF) to get it to oscillate 
> reliably (because of the extra stray capacitance I guess).
>

P.S. Use caps as specified in the PIC datasheet rather than the 
capacitor rating.