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Consider the oscillator circuit shown in the figure. The function of the network (shown in dotted lines) consisting of the 100 Ω resistor in series with the two diodes connected back-to-back is to:

1. introduce an amplitude stabilization by preventing the op amp from saturating and thus producing sinusoidal oscillations of fixed amplitude
2. introduce an amplitude stabilization by forcing the op amp to swing between positive and negative saturation and thus producing square wave oscillations of fixed amplitude
3. introduce frequency stabilization by forcing the circuit to oscillate at a single frequency
4. enable the loop gain to take on a value that produces square wave oscillations

Correct answer: introduce an amplitude stabilization by preventing the op amp from saturating and thus producing sinusoidal oscillations of fixed amplitude

Solution

The correct option is right because the network with the resistor and diodes limits the output voltage of the op amp, preventing it from reaching saturation. This allows the circuit to maintain a stable amplitude for sinusoidal oscillations, ensuring consistent performance.

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