Why do we want infinite voltage gain in an ideal opamp?

Why do we want infinite voltage gain in an ideal opamp?

• A. Since opamps are voltage amplifiers, the ideal opamp will want to amplify the incoming signal infinite times with the voltage going towards infinity
• B. To minimize power consumption
• C. To simplify the circuit by removing internal resistance
• D. To ensure the device saturates quickly

Answer: (A)

Infinite voltage gain means the op-amp responds with a huge output to even the tiniest difference between its inputs. With negative feedback, that enormous sensitivity is used to drive the input difference toward zero, so V+ and V− become almost equal. This lets the external feedback network set the actual amplification (the closed-loop gain) in a predictable, linear way, rather than letting the op-amp’s own characteristics dominate. Treating the gain as infinite is a useful idealization that explains why negative feedback yields stable, accurate amplification. In real devices the open-loop gain is large but finite, so the same principle applies closely, while the output remains limited by the power rails.

Infinite voltage gain means the op-amp responds with a huge output to even the tiniest difference between its inputs. With negative feedback, that enormous sensitivity is used to drive the input difference toward zero, so V+ and V− become almost equal. This lets the external feedback network set the actual amplification (the closed-loop gain) in a predictable, linear way, rather than letting the op-amp’s own characteristics dominate. Treating the gain as infinite is a useful idealization that explains why negative feedback yields stable, accurate amplification. In real devices the open-loop gain is large but finite, so the same principle applies closely, while the output remains limited by the power rails.