Ok heres the scenario, I am playing with LTSpice trying to make a nice smooth SMPS (32Khz) power supply for my AVR.
I can throw big caps and big inductors at it to get a nice smooth supply (but increasing the cost of the design). However will this make any difference in the grand scheme of things? Will the only difference in the universe be that I feel happy about my smoother supply, but the micro is functioning identically, and is just as robust?
I am not using the ADC.
So what are the ripple requirement to make the micro never skip a beat, and not damage/degrade it (if such a thing can happen from a repetitive spikey supplies).
As we all know engineering is a trade off, but what is the goal?
I checked out the electrical section of the datasheet with no joy.
And out of interest, with an AT90CAN32, in the bypass capacitors for a 4MHz clock, it recommends two bypass capacitors. Since I am the sucker who will be placing double caps multiple times on these boards, do I really need two different Values (the datasheet recommends 560nF and 120nF)?
Can I just slap one or two parallel 220nF (easier when its comes to buying)? I am sure it will still run, but how does one measure such robustness degradation?