5V Analog output to 3.3V

Discussion in 'General Electronics Chat' started by Diego Bonilla, Sep 19, 2014.

  1. Diego Bonilla

    Thread Starter Member

    Sep 18, 2014
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    Hi

    I have a Sensor Output 0-5V Analog, but mi Microcontroler (ADC) only support to 3.3V.

    How can accondition that signal?
     
  2. wayneh

    Expert

    Sep 9, 2010
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    Resistor voltage divider.
     
  3. ericgibbs

    AAC Fanatic!

    Jan 29, 2010
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    Use a 1K7 and 3k3 divider, a 5K trim pot is the easiest solution.
     
  4. #12

    Expert

    Nov 30, 2010
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    Many ways to skin the cat:
     
  5. Diego Bonilla

    Thread Starter Member

    Sep 18, 2014
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    Another solution?
     
  6. #12

    Expert

    Nov 30, 2010
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    4 ways isn't enough?
     
  7. Diego Bonilla

    Thread Starter Member

    Sep 18, 2014
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  8. Diego Bonilla

    Thread Starter Member

    Sep 18, 2014
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    Hi #12

    your propose have the Microcontroller power supply like a 3.3V.

    The Microcontroller Power supply are 5V, and the inputs only support 0-3.3V (ANALOG)

    Excuse mi ignorance and thanks for the help
     
  9. #12

    Expert

    Nov 30, 2010
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    Just don't connect the 3.3V to the Uc.
     
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  10. Diego Bonilla

    Thread Starter Member

    Sep 18, 2014
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    Thanks a Lot #12

    ;)
     
  11. #12

    Expert

    Nov 30, 2010
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    That's what the, "like" button is for. :)
     
  12. Diego Bonilla

    Thread Starter Member

    Sep 18, 2014
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    jijiji...sorry im new in this forum
     
  13. #12

    Expert

    Nov 30, 2010
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    No problem. That button is a new feature because all of the software for this site changed a few weeks ago.
    I just asked the important people to change it back to, "Thanks".
     
  14. ericgibbs

    AAC Fanatic!

    Jan 29, 2010
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    hi #12.
    Please check the placement of those two resistors, 10k and 4k7

    Eric.
     
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  15. #12

    Expert

    Nov 30, 2010
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    Eek! You caught me in a mistake! :eek:

    Updating now...

    Actually, I depend on peer review on this site. Everybody makes mistakes. Many eyes catch them, hopefully before they can cause much real damage. :)
     
    Last edited: Sep 19, 2014
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  16. Papabravo

    Expert

    Feb 24, 2006
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    You could also introduce an active attenuator with a gain of (3.3/5). That way the A/D input will not load the resistive voltage divider.
     
  17. Diego Bonilla

    Thread Starter Member

    Sep 18, 2014
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    hi papabravo

    how is that?
     
  18. #12

    Expert

    Nov 30, 2010
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    Very good point. Without any data about the ADC being used, the best I can do is demonstrate the math in case the values I used are inappropriate.
     
  19. Diego Bonilla

    Thread Starter Member

    Sep 18, 2014
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    with Operational Amplifiers?
     
  20. shteii01

    AAC Fanatic!

    Feb 19, 2010
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    Voltage divider followed by a buffer?

    Sensor output goes into voltage divider, voltage divider output goes into buffer made of op amp, buffer output goes to ADC.
     
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