Abstract: The invention provides a method and a modulation circuit for pulse width modulation with feedback, wherein a pulse width modulated signal is provided on the basis of an input signal and a reference signal that is periodic and has a reference frequency. The pulse width modulated signal is provided in that an output signal is switched from a first voltage level to a second voltage level in dependence on a comparison between the input signal and the reference signal at least once in every cycle of the reference signal, and in that at least once at a fixed moment in time in every cycle the pulse width modulated signal is switched from the second voltage level to the first voltage level. Furthermore, a periodic correction signal is added for compensation of the switching from the second voltage level to the first voltage level in the pulse width modulated signal.
Abstract: An amplification device, comprising a device input receiving a device input signal, an amplifier unit comprising a zero crossing detector unit, an output filter and a lead-lag compensation network. The zero crossing detector unit compares the device input signal with a reference potential and switches a pulse width modulated detector output signal between first and second voltage levels dependent on the comparison. The amplifier unit provides an actual device output signal, e.g., an amplified representation of the device input signal. The amplification device further comprises a device output providing the actual device output signal, a control loop bridging the amplifier unit and comprising a forward filter, e.g., an integrating filter, for increasing loop gain improving the signal-to-noise ratio of the actual device output signal, and a deviation detection unit detecting over modulation of the amplifier unit, so that the amplification device disables forward filter functioning upon over modulation.
Abstract: The invention provides a method and a modulation circuit for pulse width modulation with feedback, wherein a pulse width modulated signal is provided on the basis of an input signal and a reference signal that is periodic and has a reference frequency. The pulse width modulated signal is provided in that an output signal is switched from a first voltage level to a second voltage level in dependence on a comparison between the input signal and the reference signal at least once in every cycle of the reference signal, and in that at least once at a fixed moment in time in every cycle the pulse width modulated signal is switched from the second voltage level to the first voltage level. Furthermore, a periodic correction signal is added for compensation of the switching from the second voltage level to the first voltage level in the pulse width modulated signal.
Abstract: An amplification device, comprising a device input receiving a device input signal, an amplifier unit comprising a zero crossing detector unit, an output filter and a lead-lag compensation network. The zero crossing detector unit compares the device input signal with a reference potential and switches a pulse width modulated detector output signal between first and second voltage levels dependent on the comparison. The amplifier unit provides an actual device output signal, e.g., an amplified representation of the device input signal. The amplification device further comprises a device output providing the actual device output signal, a control loop bridging the amplifier unit and comprising a forward filter, e.g., an integrating filter, for increasing loop gain improving the signal-to-noise ratio of the actual device output signal, and a deviation detection unit detecting over modulation of the amplifier unit, so that the amplification device disables forward filter functioning upon over modulation.