Patent ID: 7839211

Claim:
A method for correcting for a source of non-linearity and noise introduced in a switching power amplification stage during power amplification of a pulse-modulated reference signal from a pulse modulator, the method comprising: providing an output stage embedded in an analogue self-oscillating control loop able to receive a pulse-referenced input signal; generating a feedback signal from the switching power amplification stage or after a demodulation filter following the power amplification stage; deriving an error signal by comparing the feedback signal with the reference signal; filtering the error signal by a low pass filter for reducing the higher harmonics of the carrier; adding a compensator, for generating high loop gain in the audio band; feeding the compensator output to a zero cross detector or comparator, thus providing a carrier for re-modulation or re-timing by feeding the filtered signal to a zero cross detector or comparator, which controls the output stage.