In the figure, D1 is a real silicon p-n junction diode with a drop of 0.7 V under forward bias condition and D2 is a Zener diode with breakdown voltage of -6.8 V. The input Vin(t) is a periodic square wave of period T, whose one period is shown in the figure.
Assuming 10τ ≪ T, where τ is the time constant of the circuit, the maximum and minimum values of the output waveform are respectively,
1
7.5 V and -20.5 V
2
6.1 V and -21.9 V
3
7.5 V and -21.2 V
4
6.1 V and -22.6 V