Clipping Below Reference Voltage VR

Series Clippers : Part5
       By changing the orientation of the diode in the the circuit discussed previously, we get the clipping circuit which clips the portion of waveform, below the reference voltage V_R.

       The circuit is shown in the Fig. 1.

Fig.  1 Clipping below V_R

        The diode D is an ideal diode which acts like a switch.

Operation :

       When V_i is less than V_R, the diode is reversed biased and circuit becomes open. The output voltage is equal to V_R as no current flows in the circuit. The circuit is shown in the Fig. 2(a). When V_i is greater than V_R, the diode becomes forward biased and circuit becomes as shown in the Fig. 2(b). The output voltage V_o is equal to the input voltage V_i.

Fig. 2

       The transfer characteristics equations are,

       The transfer characteristics is shown in the Fig. 3.

Fig. 3  Transfer characteristics

       The region for V_i < V_R is the clipping region while the region for V_i >V_R is the transmitting region.

       The Fig. 4(a) shows the sinusoidal input voltage V_i and the Fig. 4(b) shows the corresponding output waveform.

Fig. 4 Clipping Below V_R

Note : It can be seen that the portion of the output waveform below V_R is clipped off.