Lindy Mayfield wrote:
> When does ripple cause problems?  Will a rippled (rippling?) input
> cause a problem with PICS?

Ripple means the supply bounces around hopefully between two known limits.
First and foremost those limits must not exceed the PICs Vdd limits for its
operating mode.  As long at that is true, the PIC should continue to work.
However, the external circuit may not be so happy with that.  If you're
trying to make analog measurement, supply ripple can be a problem.  The same
is true if the PIC is trying to produce an output voltage for uses not
relative to the supply voltage.  For example, if the PIC is producing PWM
that will be low pass filtered and driven into a speaker with respect to
ground, then you will hear the ripple to the extent it is in the range of
frequencies passed by the filter and the speaker.

High frequency ripple is also bad due to its dV/dt, but that is usually not
an issue for 120Hz power line ripple.


*****************************************************************
Embed Inc, embedded system specialists in Littleton Massachusetts
(978) 742-9014, http://www.embedinc.com
-- 
http://www.piclist.com PIC/SX FAQ & list archive
View/change your membership options at
http://mailman.mit.edu/mailman/listinfo/piclist