Doubt in Non inverting amplifier

Discussion in 'General Electronics Chat' started by sudharshan.panduranga, May 10, 2010.

  1. sudharshan.panduranga

    Thread Starter Active Member

    Apr 10, 2008
    61
    1
    Help me...
    In the OPAMP non inverting amplifier, I have one doubt..
    Specification:
    Supply voltages : +/- 5V
    Gain : 10
    Input voltage : +6V

    Why opamp output gives -ve voltage. Can anybody give the reason.



     
  2. bertus

    Administrator

    Apr 5, 2008
    15,648
    2,347
    Hello,

    The input voltage may not be higher than the powersupply voltages.
    What type of opamp did you use?
    There are older types that reverse the phase at a to high input.

    Bertus
     
  3. sudharshan.panduranga

    Thread Starter Active Member

    Apr 10, 2008
    61
    1
    The OPAMP: OP27A
     
  4. sudharshan.panduranga

    Thread Starter Active Member

    Apr 10, 2008
    61
    1

    I Am using OP27A low noise OPAMP.
    Is there any theoretical reason.
     
  5. t06afre

    AAC Fanatic!

    May 11, 2009
    5,939
    1,222
    Have you downloaded the data sheet? This may be somewhat blunt. But what you are trying to do is futile, and it may fry the opamp. As the data sheet say the absolute maximum input voltage can not be higher than the supply voltage.
    Tell us what you are trying to do, and we will help you
     
  6. sudharshan.panduranga

    Thread Starter Active Member

    Apr 10, 2008
    61
    1

    I am not using this condition in the implementation. But i should know the reason reason...Can you suggest the reason...:)
     
  7. rjenkins

    AAC Fanatic!

    Nov 6, 2005
    1,015
    69
    If you operate ANY IC outside of the manufacturers specifications, it will either work poorly, malfunction or plain blow up.

    The exact type of fault or failure varies from device to device, but the fundamental cause is using the device beyond it's ratings.

    If you want more technical reasons, look at the fundamentals of integrated circuit construction, substrate isolation & thyristor effect, in addition to basic transistor biassing and breakdown vltages.
     
  8. sudharshan.panduranga

    Thread Starter Active Member

    Apr 10, 2008
    61
    1
    Thanks to all !!!!!!!
     
Loading...