A diode can reshape a waveform by changing the effective circuit when a chosen voltage threshold is crossed.

A clipper limits part of a waveform. When the diode is off, the signal follows one circuit relation; when the diode turns on, it diverts or constrains the signal so the output no longer follows the input in the same way. Adding a DC bias shifts the clipping threshold.

A clamper combines diode conduction with a capacitor to shift the waveform's DC level while approximately preserving its peak-to-peak variation. During one part of the cycle the diode establishes a capacitor charge; during the rest, that stored voltage offsets the signal.

Both circuits are analyzed piecewise. Assume a diode state, solve the corresponding linear circuit, and verify that the resulting diode voltage is consistent with that state.

Clipping changes waveform extrema; clamping primarily changes its reference level. They are distinct from rectification, whose purpose is to make current or voltage predominantly one polarity.