DNP meaning?

Discussion in 'General Electronics Chat' started by MaxHeadRoom, Apr 9, 2016.

  1. MaxHeadRoom

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    I came across a Picmicro schematic with, to me, an unfamiliar term.
    Three components have DNP in place of the value.
    I Googled the abbr. DNP and it mentions in PCCT use 'Do Not Place'
    So what would be the intention of putting it on the schematic in the first place?
    Max.
     
  2. bertus

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  3. MaxHeadRoom

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    This is a 1/2 dozen component analogue to I2c convertor circuit !! ??
    Max.
     
  4. nsaspook

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    Design development work parts not needed in the released version or revision?
     
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  5. MaxHeadRoom

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    I sort of figured that but the fact the schematic sheet had a revision notes box, I figured they would just simply amend the schematic.
    A couple of cases are two resistors in parallel one has a Designation # and a value, the other designation #, but DNP in place of the value, IOW if you are revising the schematic, omit it?:confused:
    It is no big deal, but just had me puzzled as I had never seen that on a circuit from Microchip before.
    Max.
     
  6. SLK001

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    DO NOT PLACE. Used when you want a placeholder for a possible modification at a later date, but not needed in the present version.
     
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  7. MaxHeadRoom

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  8. nsaspook

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    Maybe someone had a hot date that night.
     
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  9. bertus

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    Hello,

    It could also be the case that the "Do Not Place" parts have been used during a test period.

    Bertus
     
  10. MaxHeadRoom

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    But why would you include them in a final print and board outline?;)
    Max.
     
  11. bertus

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    Hello,

    Perhaps to verify things that where done during testing or for troubleshooting.

    Bertus
     
  12. MaxHeadRoom

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    I am just putting myself in the role of designing the board, I can see a totally separate component not needed after testing, in this case say, C3 DNP, but in the case of designing a pairs of resistors in parallel and adjacent to each other, surely one component is all that is needed and if it is found later for a value change then this is noted in the rev box.?
    Unfortunately they did not document the rev's in detail.
    Max.
     
  13. recklessrog

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    I designed a controller for an annealing oven many years ago, and submitted the schematic to the pre-production dept. They got back to me several days later and said " we've asked every supplier for an "A.O.T resistor, but no one stocks one"!!!!!!!!
    Due to poor tolerance's with the proposed thermistor used for sensing, I had marked a resistor as A.O.T..........Assessed On Test.
     
  14. GopherT

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    If you look at AV Receivers, some brands, Denon & Sony, seem to use the same board for multiple models in a given year - The high-end include components in a particular area and some lower end models have no components in that area.
     
  15. SLK001

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    Where I used to work, we used the same radio PCB for many different versions. The PCB could accomodate them all, and every version would have a schematic based on the original with the different values and the DNP components (since the number of parts on the schematic net list had to equal the number of parts on the PCB for pick and place machines).

    For instance, I designed the RF transmitter modules and these had both high power and low power versions. On the high power versions, the power transistor required biasing thru a resistor, but the low power version required no bias. On the low power schematic, the biasing resistor was shown with a value of DNP. On the PCB the pads were there, but nothing was placed in that positition.
     
  16. Dr.killjoy

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    I am not sure if correct here but I always thought DNP means Do Not Populate.. I can't remember where I learned it from but it works for me..
     
  17. SLK001

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    Do Not Populate = Do Not Place... pretty much the same meaning.
    Also,
    Do Not Pepper,
    Do Not Precipitate,
    Do Not Presume,
    Do Not Prepare...
     
  18. bertus

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  19. KeepItSimpleStupid

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    In the micro-chip case, the pull-ups would change based on Vdd
     
  20. recklessrog

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    How about "Do not pontificate" lol :)
     
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