Well I am been designing a product at work and we've decieded to use an LM2576 ADJ. Everything is fine. However, I am not satisfied when it comes of to the RMS Current rating of the output/input caps. According to the data sheet of LM2576:
1- Input Cap should have a RMS ripple current rating of 2.14 A (RMS) and 1000uF rating (overkill)
2- Output cap should have a RMS ripple current rating of 1.65 A (RMS) and 1000uF rating (overkill)
I figured I can use same rating for both the output cap and input cap (2.14 A-rms being the case).
However, my question is:
IF I parallel say, two 680uF (two on the input and two on the output), would they share the RMS ripple current requirement? As in, would the RMS requirement be split into two becaz now I have two "banks" for the circuits current requirement.
OR should I just use 1000uF @ the required RMS current rating? (kind of an expensive option though)
Price vs Reliability .. the age old dilemma
All insight is appreciated!!