Ceramic capacitor, does the size matter?

I am making a buck power supply and I need on the input and the output 4x 22uF @ >5V ceramic capacitor.

Even at 10V I find plenty of cheap X5R MLCC in the sizes 0603, 0805 or 1206. By looking at this datasheet, I don't see any noticeable difference between these models.

I guess the smaller is the better, am I right?

Answers 1

    • the size is less sensitive to ESR in the AVX source range you linked but the voltage rating and bias has a significant effect on reducing C value.
    • In order to make the voltage rating greater the size must be increased so bigger can be better
    • the chip with the greater Vmax rating in any family will have a greater C value used at 50% vmax. with a higher Vmax rating. Choices are slim with 16 or 10V @ 22uF in MLCC
    • Also supplier choice makes a big difference and in this category, I would suggest TDK’s X6S parts with 10 mOhm ESR over AVX parts with 100 mohm for ripple reduction.

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