Placing 4 smps on 1 board

Discussion in 'General Electronics Chat' started by Garurumon, Oct 1, 2013.

  1. Garurumon

    Thread Starter Member

    Mar 17, 2013
    99
    1
  2. Garurumon

    Thread Starter Member

    Mar 17, 2013
    99
    1
    Hmm.. What topology? I don't get it :/
     
  3. crutschow

    Expert

    Mar 14, 2008
    13,014
    3,234
    You can put all four power supplies on the same board if you are careful about layout and decoupling.

    The common ground should be a continuous PCB ground plane covering the whole PCB area.

    Each supply should have it's own input decoupling capacitor.

    The input decoupling capacitor, MOSFET switch, free-wheeling diode, and output inductor should be connected as close together as possible to minimize the distance the current must flow between these devices.
     
  4. mcgyvr

    AAC Fanatic!

    Oct 15, 2009
    4,770
    970
    yep and everything else in the "PCB layout" suggestion section of the datasheets..

    making it for a diy project is one thing..needing that board to meet FCC/EMI/EMC testing is another..
     
  5. Garurumon

    Thread Starter Member

    Mar 17, 2013
    99
    1
    Thanks... And inductor position, should I just place them as far as possible from each other, or I have to change their orientation, rotate them and stuff?
     
  6. joeyd999

    AAC Fanatic!

    Jun 6, 2011
    2,684
    2,745
    You do know that a 3.3V linear supply, driven by 9V has, at best, 37% efficiency, yes?

    And, assuming the 3.3V supply is at a higher current than the 9V supply (a generally safe assumption), the 9V supply would have to be overdesigned to not only handle the 9V circuit current consumption, but that of the 3.3V circuit as well?

    What you might do may not be best for the OP's application.
     
    sheldons likes this.
Loading...