Abstract: Switching power amplifier includes a first signal path having a pulse modulator for modulating an input signal, and a switching power unit for amplifying the modulated signal to generate an amplified output signal; a second signal path for generating a reference signal in response to the input signal; and a sigma delta feedback loop having a substractor for substracting the generated reference signal from the amplified input signal to generate an error signal, an analogue noise shaper for integrating the error signal to generate an integrated error signal, and a quantizer for converting the integrated error signal into a digital feedback signal which is fed back to the first signal path.