What is so special about MUETA®’s modulator?
The hysteresis modulator in the MUETA® amplifiers works on zero-input. Together with the controller, which regulates the error to zero, this is an ideal combination because in case of a non-zero error on its input, the modulator reacts immediately to correct this. On the other hand, because conventional modulators make a direct translation from signal to duty-cycle, they require a non-zero input. To generate a correct filter output, an additional non-zero correction signal is required at the modulator input. This is fundamentally imperfect since the generation of this correction signal requires the error to be non-zero! To make things worse, the amount of correction required increases for higher frequencies when there is less time to generate it. This is why filter output feedback will not work on switching amplifiers with a conventional modulator. MUETA® controls the slope of the output rather than the output voltage. This is a form of predictive control. MUETA® amplifiers are therefo
