Apparatus and a method for restoring an A-level clipped signal

摘要

A circuit which restores portions of an input signal lost due to clipping distortion includes a comparator which locates the portions of the input signal which have been subject to clipping distortion and generates a pulse signal where each pulse corresponds to a clipped portion of the input signal. This pulse signal is used to generate parabolic pulses which are combined with the input signal to generate a modified signal that approximates the input signal without the clipping distortion. One circuit generates the pulse signals by controlling an oscillator to produce a parabolic pulse train which changes in frequency and amplitude to match each pulse of the pulse signal and then selecting one of the parabolic pulses for each pulse of the pulse signal. Another circuit generates the parabolic pulses by doubly integrating the pulses of the pulse signal.