Question 18.16: Fig. 18.42 shows a zener shunt clipper with sine wave input....
Fig. 18.42 shows a zener shunt clipper with sine wave input. Determine the output waveform.
The zener shunt clipper uses a zener diode in place of the ordinary diode. The zener shunt clipper uses both the forward and reverse characteristics of the zener diode. Thus when the zener diode is forward biased, this clipper acts just like the standard shunt clipper.
When the input signal in Fig. 18.42 goes positive, the zener is reverse biased. Therefore, the zener diode will remain OFF until the value of V_{\text {in }} \text { reaches the value of } V_Z. At that time, the zener diode will turn ON, clipping the input signal. As long as V_{\text {in }} \text { is greater than } V_Z, the zener will remain ON and the output voltage is
V_{\text {out }}=V_Z
When the input signal goes negative, the zener is forward biased. Therefore, the zener is clipped off at 0.7 V.