Patent ID: 7425853

Claim:
A pulse width modulation system comprising: an asymmetric correction unit; a first modulator coupled to the asymmetric correction unit; a second modulator coupled to the asymmetric correction unit; wherein the asymmetric correction unit is configured to receive samples of an input signal; and wherein for each sample, the asymmetric correction unit is configured to determine whether a signal level of each sample is one of a set of symmetric signal levels or one of a set of asymmetric signal levels, when the signal level of the sample is one of the symmetric signal levels, forward the sample to each of the modulators, and when the signal level of the sample is one of the asymmetric signal levels, forward a first modified sample to the first modulator and a second modified sample to the second modulator, wherein the signal level of one of the modified samples is increased by a selected amount to one of the symmetric signal levels and the signal level of the other of the modified samples is decreased by the selected amount to one of the symmetric signal levels.