Adc0804,dac0808

Discussion in 'Homework Help' started by TAKYMOUNIR, Nov 7, 2013.

  1. TAKYMOUNIR

    Thread Starter Active Member

    Jun 23, 2008
    351
    1
    Hi ,I have problem with the ADC when I put the input on pin 6 sinewave (2 KHZ 5vp-p) once I put the input on pin 6 I see that the signal is get clipped mean the negative part of the signal is gone and only I have the half positive of the signal so can someone help me
     
    • ADC.jpg
      ADC.jpg
      File size:
      67.2 KB
      Views:
      31
  2. shteii01

    AAC Fanatic!

    Feb 19, 2010
    3,387
    497
    I guess your ADC does not recognize negative voltages. Check the datasheet to see which voltages your ADC is designed to work with.

    Or you could move the offset up. I assume right now you have sine wave from -5 volt to +5 volt. If you move the offset up by 5 volt, you sine wave will be from 0 volt to 10 volt. Again check the datasheet of your ADC to see if it accept 10 volt input.
     
    TAKYMOUNIR likes this.
  3. shteii01

    AAC Fanatic!

    Feb 19, 2010
    3,387
    497
    Ok. I just checked my textbook. The very very very very basic setup for ADC0804 is input Vin(+) is from 0 volt to 5 volt. So it will simply ignore all the negative voltages you are sending to it. The negative voltages all become 0 volt because that is the lowest that the chip can take.
     
    Last edited: Nov 7, 2013
    TAKYMOUNIR likes this.
  4. TAKYMOUNIR

    Thread Starter Active Member

    Jun 23, 2008
    351
    1
    thanks it works ok now with positive vin
     
  5. TAKYMOUNIR

    Thread Starter Active Member

    Jun 23, 2008
    351
    1
    thanks so much,it works now ,and last question when i put 1 vp-p(100 HZ) on pin 3 ,the chip stop working,so is what is the problem
     
Loading...