Difficulty: Easy
Correct Answer: Correct
Explanation:
Introduction / Context:
Despite wide variation among families, most general-purpose op-amps share a recognizable internal architecture: a differential input stage for high input impedance and common-mode rejection, one or more high-gain intermediate stages, and an output stage capable of driving loads. Recognizing these blocks helps explain datasheet parameters such as input offset, open-loop gain, slew rate, and output swing.
Given Data / Assumptions:
Concept / Approach:
The input differential pair compares the two input voltages and converts their difference into a current/voltage signal while rejecting common-mode components. A high-gain stage (often a Miller-compensated voltage amplifier) provides most of the open-loop gain and sets the dominant pole for stability. The output stage buffers the high-gain node, supplies current, and reduces output impedance, enabling the op-amp to drive external loads and feedback networks robustly.
Step-by-Step Solution:
Verification / Alternative check:
Block diagrams in op-amp datasheets routinely depict this three-stage arrangement; application notes explain how each stage contributes to closed-loop behavior and stability.
Why Other Options Are Wrong:
Common Pitfalls:
Assuming the presence of AC coupling between stages; forgetting that compensation and protection circuitry are support functions, not replacements for the core stages.
Final Answer:
Correct
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