Exam-style question
Try this first
Explain how the bandwidth of a real operational amplifier limits its ability to amplify high‑frequency signals, and describe the role of slew rate in this limitation.
Model answer
What a good answer should say
- The bandwidth is the frequency range over which the op‑amp can maintain its specified gain; above this range the gain falls, so the output no longer follows the input accurately.
- The slew rate limits the maximum rate of change of the output voltage; for a sinusoidal input the peak output slope is 2πfVout.
- When the required slope exceeds the slew rate, the output becomes distorted even if the frequency is below the bandwidth.
- Thus both bandwidth and slew rate together determine the fidelity of high‑frequency amplification.
Explanation
Why this works
The answer demonstrates a clear understanding of how bandwidth limits gain at high frequencies and how slew rate limits the maximum output voltage swing per unit time. It shows the student can link these two physical limits to the distortion of the output waveform, directly addressing the objective.
Common mistake
No common mistake is linked to this question yet.