Systems and methods for minimizing errors due to component variation in
switching amplifiers utilizing power supply feed forward techniques. One
embodiment comprises a digital PWM amplifier having an amplification
subsystem for receiving a digital audio signal and producing an analog
output signal. The amplifier includes a power supply feed-forward path
configured to modify the digital audio signal based on a power supply
measurement. The feed-forward path includes an analog filter configured
to filter the power supply measurement, as well as correction circuitry
configured to correct component mismatch errors introduced by the filter.
The power supply measurement may be a power supply difference, a power
supply common mode, or both. In either case, the power supply measurement
is corrected by multiplying the measurement by an appropriately scaled
power supply difference.