Electronic – switch mode power supply capacitors

capacitorlayoutswitch-mode-power-supply

If I am laying out two switch mode power supplies right next to one another from the same supply(24V), one is switching to 5V and the other to 12V then do I need both of the input capacitors? Thanks

Best Answer

For a buck converter you want grounded pins of input, output caps and diode to be placed close together (among other things). This will be hard to do if two converters share the same input cap. More information about proper DC-DC converter layout can be found in Linear Tech. appnote 136:

http://cds.linear.com/docs/en/application-note/an136f.pdf