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Need a solution for comparator circuit

  1. Dec 2, 2015 #1
    I have problem with this circuit. Normally when vP>vN (if I set vN>0.4V), output vQ is equal 5v. But when I set vN < 0.4V, output is not true, it is always 5V not only for vP< vN but also vP>vN. I need to design ADC circuit, and that is comparator block. Need some suggestions. Help me
    . Untitled_zpscwhwwz95.png
    I supply V = 5V, vG = 0V, VPbias = 0V
  2. jcsd
  3. Dec 2, 2015 #2
    I as well would like to know this...
  4. Dec 2, 2015 #3


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    Science Advisor

    Start with eliminating all but the most basic things. This means removing XM8, 9 and 10. If it still does not work, try increasing VPbias. If it still does not work - I am currently out of ideas.
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