Diode Applications: Clamping Circuits

A clamper is a circuit that is designed to shift a waveform above or below a dc reference voltage without altering the shape of the waveform. This results in a change in the dc average of the waveform.

Both of these statements are illustrated in the figure below. (The clamper has changed the dc average of the input waveform from 0 V to +5 V without altering its shape.)

A clamper with its input and (ideal) output waveforms.

Diode Applications: Clipping Circuits

Clippers or Diode Limiters are networks that employ diodes to "clip" away a portion of an input signal without distorting the remaining part of the applied waveform. For a clipping circuit at least two components—an ideal diode and resistor are required and sometimes a dc battery is also employed for fixing the clipping level. The diode acts as a closed switch when forward biased and an open switch when reverse biased. The input waveform can be clipped at different levels by simply changing the voltage of the battery and by interchanging the positions of the various elements.