Op Amp Integrator question

Discussion in 'General Electronics Chat' started by bitrex, Dec 18, 2009.

  1. bitrex

    Thread Starter Active Member

    Dec 13, 2009
    If I have an op amp configured as an integrator, with a capacitor from the output to inverting input and non-inverting input grounded, and connect the inverting input through a resistor to the negative supply, the output should ramp up linearly. My question is how the op amp does this? The analysis assumes that the negative input is at virtual ground, but with only a capacitor in the feedback loop and a DC voltage applied at the input how does the output cause the inverting input to stay at virtual ground? Thanks for any insight.
  2. hgmjr

    Retired Moderator

    Jan 28, 2005
    Are you familiar with the behaviour of a capacitor when it is charged from a constant current source?

    This is the key to your opamp question.

  3. lmartinez

    Active Member

    Mar 8, 2009