Digital-input class-D amplifier

An apparatus including a class-D amplifier, comprising:

• modulator means for
• receiving and converting a digital input signal to a first multivalue digital signal corresponding to said digital input signal, and
• receiving a feedback signal and in response thereto receiving and converting an analog input signal to a second multivalue digital signal corresponding to said feedback signal;
• first combiner means for combining said first and second multivalue digital signals and providing a third multivalue digital signal corresponding to a sum of said first and second multivalue digital signals;
• converter means for converting said third multivalue digital signal to first and second binary digital signals with first and second binary signal values that vary in relation to said third multivalue digital signal;
• and
• second combiner means for combining said first multivalue digital signal and said first and second binary digital signals and providing said feedback signal.

A method for class-D signal amplification comprising:

• performing delta-sigma modulation of a digital input signal to generate a first multivalue digital signal corresponding to said digital input signal;
• receiving a feedback signal and in response thereto performing delta-sigma modulation of an analog input signal to generate a second multivalue digital signal corresponding to said feedback signal;
• combining said first and second multivalue digital signals to generate a third multivalue digital signal corresponding to a sum of said first and second multivalue digital signals;
• converting said third multivalue digital signal to first and second binary digital signals with first and second binary signal values that vary in relation to said third multivalue digital signal;
• and
• combining said first multivalue digital signal and said first and second binary digital signals to generate said feedback signal.