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STM32F4-Discovery PDR_ON

Discussion in 'ARM' started by AtomSoft, Mar 6, 2012.

  1. AtomSoft

    AtomSoft Well-Known Member

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    Ok there is a PDR_ON pin which i can see is the Power Down Reset pin.... but how does one connect to it?

    I tried following the schematic on the STM32F4-Discovery board but it tells me R27 isnt fitted.. i assume that means its not populated and it says nothing on R28. Both resistors touch the PDR_ON pin. So im not sure what to follow?

    Should i do whats on the board and FIT a 0 ohm or straight connect VDD.... ? or listen to schematic and tie to GND?

    Im kind of lost... Attached are pictures of the schematic portion from the Discovery Datasheet and the actual board image where R27 is in place but not R28...

    Perhaps its a silk screen error?
     
  2. AtomSoft

    AtomSoft Well-Known Member

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    Ok in another datasheet i notice:
    So i think i should tie to VDD with either a 0 ohm or straight

    UPDATE: It is tied to VDD on my board... just used a DMM to figure it out. So i guess R27 is fitted and R28 isnt fitted. Perhaps a schematic note error.
     
    Last edited: Mar 6, 2012
  3. AtomSoft

    AtomSoft Well-Known Member

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    In another datasheet i found this info:

    Crazy how all of this is separated into different parts... But I will conclude that it has to be:

    TIED to VDD

    Even tho it says its not used on LQFP100 and LQFP64 but JUST IN CASE! since it is available i recommend to tie it to VDD since that's what's need to be done for the other packages and what is done on the actual PCB.

    I hope this is useful to others out there.
     
  4. dave

    Dave New Member

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  5. AtomSoft

    AtomSoft Well-Known Member

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    Take a look:

     

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