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5V regulator outputting 5.9V and more.

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james_s:
You could also test a sample if you have an oscilloscope and a resistor. With the addition of a function generator you can lash up a little low pass filter and observe the characteristics under realistic conditions. I think Kemet is decent stuff but I can't speak for their documentation offhand. It's possible that this data is buried in some other document instead of the individual datasheets. As I mentioned previously it's not nearly as widely known or as well publicized as it ought to be. I think a LOT of people get snared in that trap, but in many cases the reduced capacitance doesn't cause obvious problems so it is never noticed.

floobydust:
MLCC selection is much more dangerous now due to manufacturers "race to the bottom" for smallest size. The push is to go down a size group with the "same" ratings. 1210 obsolete in favour of 1206, 0805 for 0603 etc.
So the voltage coefficient of capacitance effect is much greater now. 0603 is only about 33%of rated C at 5V for a 25V part, whereas 1206 is around 90% - you want the physically biggest part.
TDK MLCC allows you to sort by the capacitance with DC bias, which helps a lot.
Taiyo Yuden also allows DC bias sort and check.

wraper:

--- Quote from: floobydust on December 09, 2019, 11:56:55 pm ---0603 is only about 33%of rated C at 5V for a 25V part, whereas 1206 is around 90% - you want the physically biggest part.

--- End quote ---
Depends on capacitance for size. Say if you take 4.7uf and 22uF part with same size and 6.3 V rating, there are chances that at 5V actual capacitance is almost the same for both.

floobydust:
Yes, there seems to be a density where it makes more sense to use a lower value part. Temperature and aging are also worth looking at.
Example 0603 6.3V at 5V:
47uF  gives 9.4uF -80%
22uF  gives 4.4uF -70%
10uF  gives 3.0uF -70%
4.7uF gives 3.3uF -30%

viperidae:
That 4.7 is an x7r dielectric and the others are x5r. I think that's why it's better

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