Virtual ground

Discussion in 'General Electronics Chat' started by Gagneet, Aug 27, 2014.

  1. Gagneet

    Thread Starter New Member

    Aug 26, 2014
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    Is virtual ground concept a property that arises due to internal structure of operational amplifiers or due to circuit configuration?
     
  2. ronv

    AAC Fanatic!

    Nov 12, 2008
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    It is usually used when you want to use only one power supply to power an amplifier. You create a virtual ground at 1/2 the supply voltage so the signal can swing above at below it.
     
  3. MikeML

    AAC Fanatic!

    Oct 2, 2009
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    Virtual ground is equivalent to biasing, as in biasing a signal to be centered in the linear region of an amplifier.
     
  4. crutschow

    Expert

    Mar 14, 2008
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    Another definition of a virtual ground, in addition to that previously discussed, is the summing junction of an op amp configured as an inverter with the (+) input grounded. In that configuration the (-) input will stay very close to ground potential due to the negative feedback as determined by the high open-loop gain of the op amp and its input offset (as long as the op amp output is not saturated). Since the (-) input stays very close to ground potential, even though it is not connected to ground, it is referred to as a virtual ground point.

    I prefer the term pseudo-ground for a reference point at 1/2 the supply voltage to differentiate it from the op amp input virtual ground but that is not a commonly used designation.

    So, in answer to your question, this type of virtual ground is a property of the op amp circuit configuration.
     
  5. Gagneet

    Thread Starter New Member

    Aug 26, 2014
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    thanks so much
     
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