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PLL vs FLL vs Power Consumption?

Question asked by Doug Paulsen on Aug 21, 2014
Latest reply on Aug 25, 2014 by TomE

Is there any documentation regarding Coldfire power consumption when running PLL clock modes versus FLL clock modes versus neither?

 

I appreciate this is a complex subject and numerous variables are involved, but this particular ColdfireV1 project is found to draw 3-4 times the current it was expected to use.  A little burn 'n learn later, is was determined using PLL was the culprit.  In BPLPE mode, current consumption was as calculated.  Alas, the project code was premised on higher clock rates derived from using PLL.

 

If one googles around a bit, there are occasional comments that PLL modes are the most power hungry (and the most accurate clocks), FLL are less so in both categories, but that's essentially the level of detail that is presented.

 

Thanks for any clarification, although it looks in this case like compromises are in the future.

 

Doug

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