Systems and methods for minimizing performance degradation due to
component mismatch in the feedback path of a digital PWM amplifier
feedback loop. One embodiment comprises a digital pulse width modulated
(PWM) amplifier with feedback. The amplification subsystem receives a
digital audio signal and produces an analog output signal. The feedback
loop produces a feedback signal based on the filtered analog output
signal and modifies the digital audio signal based on the feedback
signal. The feedback loop includes a filter configured to filter the
analog output signal and correction circuitry configured to correct
component mismatch errors introduced by the filter. In one embodiment,
the correction circuitry receives a measurement of a power supply
voltage, multiplies the measured voltage by a gain and adds the scaled
measurement to the feedback signal to correct for the component mismatch
errors.