A close-down pop reduction system and a method for close-down pop reduction in an audio amplifier assembly are disclosed. The switching power conversion system comprises a forward path having a compensator and a switching power stage and a signal path from an output of a comparator in the switching power stage to a sequence control unit. The signal path includes a close-down timing circuit configured to provide a timing signal. The sequence control unit is configured to eliminate the input signal, increase the switch frequency of the close-down pop reduction system and disable the switching power stage at a moment in time within a PWM pulse of the switching power stage. Hereby, it is e.g. possible to minimize the audible pop during close-down of audio amplifier assemblies.

A class-D amplifier system includes one or more pulse width modulation (PWM) output paths at least one of which includes one or more digital closed-loop PWM modulators (DCL-PWMM) in which at least one of the DCL_PWMM includes a digital integrator that provides an output value and receives a feedback value. The output value has an output resolution and the feedback value has a feedback resolution that is coarser than the output resolution. The output value is the sum of an integer multiple of the feedback resolution and a residue. Control logic decreases/increases the residue of the digital integrator toward an integer multiple of the feedback resolution over a plurality of clock cycles in response to a request to transition the class-D amplifier and forces an output of the DCL_PWMM to have an approximate 50% duty cycle after decreasing/increasing the residue over the plurality of clock cycles.

A close-down pop reduction system and a method for close-down pop reduction in an audio amplifier assembly are disclosed. The switching power conversion system comprises a forward path having a compensator and a switching power stage and a signal path from an output of a comparator in the switching power stage to a sequence control unit. The signal path includes a close-down timing circuit configured to provide a timing signal. The sequence control unit is configured to eliminate the input signal, increase the switch frequency of the close-down pop reduction system and disable the switching power stage at a moment in time within a PWM pulse of the switching power stage. Hereby, it is e.g. possible to minimize the audible pop during close-down of audio amplifier assemblies.