
noninverting inputs is also 0 V. The opamp, which amplifies this difference, has
no difference to amplify.
Now, if the input changes suddenly from 2 V to 2.1 V, there will be a difference
between the two inputs—the noninverting input is at 2.1 V, and the inverting
input, still connected to the output, is at 2 V. The 0.1 V difference is amplified by
the opamp, which starts to move the output toward a more positive voltage as
soon as the output reaches 2.1 V, the difference between the two inputs is again 0,
and the output stays at that voltage.
If the temperature changes and the opamp output transistors change char-
acteristics slightly, they might