Capacitors for DC/DC converter

Question

I am using a DC/DC converter (buck) in a power distribution board to convert 48V to 12V. Link to the chosen converter is given below. After reading the datasheet, I've concluded with using a 560 μF aluminium electrolytic capacitor at the input pins to keep the voltage stable. At the output I'm thinking of using 2× 10 μF ceramic capacitor to reduce the ripple voltages and noise.

The problem is; I dont have any experience with building boards such as this, so I would like to know if this setup for the DC/DC converter would do okay, or what I have to do different?

Answer 1

No, your selection is not okay. The datasheet recommends 660 uF at each converter input, with less than 0.7 Ohm internal impedance at 100 kHz. Not every electrolytic capacitor can meet these parameters. You might want to employ an array of smaller caps to meet the 700 mOhm at 100 kHz requirement.

More, to ensure the advertised parameters (ripple level etc.) one 10uF cap is not enough. The datasheet suggests the following filter circuit at the output:

Please read the datasheets more carefully.