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???
06/28/04 13:35
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#73272 - RE: Xtal Osc.
Responding to: ???'s previous message
I use the rule of thumb: if all that is clocked is ONE uC, use the internal osc, if ANYTHING more, use an oscillator.
An experience: if more than one frequency is required, do not use several oscillators, use one and a divider or, in some cases, you can use T2out, as a last resort a PLL will do it. If you have several oscillators, it is near impossible to keep them from 'biting' and using one divided for the remaining clocks makes the layout so much simples since biting is not a concern. I learned this one with a chopper stabilized op-amp and a uC on the same board. Since the problems with analog and logical on the same board are well known a long time was spent on noise hunt before the problem was realized as oscillator biting. Replacing the chopper clock with T2out removed the 'noise'.

Erik

List of 9 messages in thread
TopicAuthorDate
Xtal Osc.            01/01/70 00:00      
   RE: Xtal Osc.            01/01/70 00:00      
      Thanks Michael            01/01/70 00:00      
         RE: Thanks Michael            01/01/70 00:00      
            All about crystal terminology            01/01/70 00:00      
      Also a disadvantage...            01/01/70 00:00      
         14 Pin and 8 in Xtal Osc.            01/01/70 00:00      
            RE: 14 Pin and 8 in Xtal Osc.            01/01/70 00:00      
   RE: Xtal Osc.            01/01/70 00:00      

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