Question

In the given circuit the input voltage V_in is shown in figure. The cut-in voltage of p–n junction diode
(D₁ or D₂) is 0.6 V. Which of the following output voltage (V₀) waveform across the diode is correct?

• A.

  

• B.

  

• C.

  

• D.

  

Answer 1

The Correct Option is A

 To determine the correct output voltage (\(V_0\)) waveform across the diode, let's analyze the given circuit and input signal:

The input voltage (\(V_{\text{in}}\)) is a sinusoidal waveform with an amplitude above and below 0.6 V. The diodes \(D_1\) and \(D_2\) have a cut-in voltage of 0.6 V.

Step 1: Analyze the positive half cycle of \(V_{\text{in}}\).

During the positive half cycle, when \(V_{\text{in}} > 0.6 \, \text{V}\), diode \(D_1\) becomes forward-biased. This allows current to flow, and the output voltage \(V_0\) will be approximately \(0.6 \, \text{V}\) (considering the voltage drop across \(D_1\)).

Step 2: Analyze the negative half cycle of \(V_{\text{in}}\).

During the negative half cycle, when \(V_{\text{in}} < 0\, \text{V}\) (or more negative), diode \(D_2\) becomes forward-biased if the input voltage is less than \(-0.6 \, \text{V}\). This also results in an output voltage of approximately \(0.6 \, \text{V}\), as \(D_2\) conducts.

Conclusion:

Both diodes only conduct when their respective threshold voltages are exceeded (0.6 V or -0.6 V), clipping the output voltage to approximately 0.6 V during each half-cycle.

Therefore, the correct waveform for \(V_0\) is the clipped waveform that remains at approximately 0.6 V during both positive and negative cycles.