Why multiple capacitors in parallel?

[madhu.wesly01]

Hi,

Wondering why you would choose to use smaller capacitors in parallel vs one bigger one. Can I use a single 47uF capacitor at the output, or I have to place 4 X 10uF capacitors as given in datasheet?? Will there be any difference??

Could you also let me know in general how to decide on capacitor package(size) used at input and output of the regulator ??

Thanks in advance.

[EEVblog]

[EEVblog]

Could you also let me know in general how to decide on capacitor package(size) used at input and output of the regulator ??

Basically just follow the datsheet advice. They often have entire sections devoted to choosing a bypass capacitors.

[b_force]

Besides ESR it can also be cheaper or sometimes just fits better on the PCB when there are size limitations.
A 100uF is a lot smaller (height) than a 470uF.

In a lot of cases it's also easier to fit four smaller sized caps on a PCB than one big one (that will screw up your layout)

[Karlo_Moharic]

Redundancy

[Ice-Tea]

Redundancy

Not really. They tend to fail short. So adding more caps essentially increases the likeliness the entire unit fails.