Pure opamp integrator definition

[zzlong94]

The definition of pure opamp integrator is also known as ideal integrator?
which means the integrator would not need a feedback resistor Rf to connect parallel with feedback capacitor, Cf?

[rstofer]

Correct, there is no resistor in the feedback path.

I use the integrator circuit for analog computing.  The input resistor is 1Mohm and the timing capacitor is 1ufd so the time constant is 1 second.  That turns out to be 'real time' for the problems I play with.

[Zero999]

In an op-amp integrator, the capacitor is charged/discharged, with a constant current, which is directly proportional to the input voltage. The advantage over an op-amp integrator, to a plain old RC circuit, is the current flowing in/out of the capacitor is independent of the voltage on the capacitor. Of course this assumes that the op-amp's output is not saturated.