Operational Amplifier Fundamentals Unit 2 – The Inverting Amplifier
Exercise 2 – Inverting Amplifier AC Operation
EXERCISE OBJECTIVE
When you have completed this exercise, you will be able to operate an inverting amplifier using
an ac input. You will verify circuit operation with an oscilloscope.
EXERCISE DISCUSSION
- An inverting amplifier can amplify ac input signals. Concepts of virtual ground, circuit
summing point, and closed-loop operation do not change. - An output waveform is phase shifted by 180°.
- Output amplitude is affected by the ratio of RF to RIN.
- VO(pk-pk) = Vi(pk-pk) x (RF/RIN)
- Nondistorted peak-to-peak output voltage is limited by the dc value of the power supplies.
- LF441 op amp output voltage is limited to about 85% of the dc power supply.
- If the product of the peak value of an input waveform and the circuit gain is too high, the op
amp distorts its output waveform. This is called saturation distortion. - Amplitude distortion is generally symmetrical unless the op amp is not balanced, then
distortion becomes asymmetrical: one peak distorts before the other.