Virtual ground

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

  1. Gagneet

    Thread Starter New Member

    Aug 26, 2014
    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
    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
    Virtual ground is equivalent to biasing, as in biasing a signal to be centered in the linear region of an amplifier.
  4. crutschow


    Mar 14, 2008
    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
    thanks so much