This is probably a very basic question. How do you shut down a textbook op-amp integrator without driving the inverting input well below the negative rail?
The part is a basic LM324, powered with 0-15V. It is used to create a very slowly rising 0-10V ramp. Input resistor is 1Mohm and the cap is 1000 microF. Op amp load is purely resistive 667ohm. My concern is that once the power is off, the positive terminal of the cap becomes ground and negative swings to -10V at the inverting input, a la charge pump. I thought about a Schottky diode from ground to the inverting input but is that enough to discharge 1000 microF with less than 0.3V across the diode?