3.4 Operational amplifiers

I declare: solidlikelyshaky

1. State the two golden rules of the closed-loop op-amp and use them to calculate the gain of an inverting and a non-inverting amplifier.
2. Build a follower, show what it changes for a loaded voltage divider.
3. Build a comparator with hysteresis and explain why without it the output chatters around the threshold.
4. Amplify a shunt’s voltage to measure a motor current, and compare to the clamp meter.
5. Read the supply range, rail-to-rail and output current on the datasheet, and say which op-amp suits 3.3 V.
6. Build a summer and an integrator, and say what an instrumentation amplifier is for in a differential measurement.
7. Read offset voltage, common-mode rejection ratio and gain-bandwidth product on the datasheet, and say when they matter.
8. Diagnosis: an op-amp whose output is stuck to a rail, open loop, input out of range, or single supply where a dual was needed.