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Unread 22-01-2004, 12:48
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Al Skierkiewicz Al Skierkiewicz is offline
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AKA: Big Al WFFA 2005
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Re: PIC XT oscillator question.

Quote:
Originally Posted by KenWittlief
we keep switching words here between crystal, oscillator and (ceramic) resonator.
these are three different things
Ken,
Like many microprocs or microcontrollers, this chip has an onboard oscillator that can use either a ceramic resonator, crystal, an RC oscillator or an external clock. The External clock option might be needed if there was a need to run this from a master for some reason, but as a stand alone it may not be worth the extra expense. I made the recommendation on cost, parts count and complexity. I am sorry for any confusion on the use of the terms and hope that everyone understands that given the right circuitry a crystal and/or a ceramic resonator and/or an RC network all work well in an oscillator. The stability of an oscillator is what governs the decision on which to use. Least stable being the RC followed by the ceramic, crystal, external clock, temperature stabilized (oven) external crystal oscillator and finally atomic reference. I would think in this application the crystal at 4X PLL is the way to go.
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Al
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