Class D amplifiers

摘要

A 3-level class D amplifier circuit comprises a first comparator for comparing an input with a first triangular reference and a second comparator for comparing the input with a second triangular reference. A phase relationship between the signals to the first comparator is 180 degrees shifted relative to a phase relationship between the signals to the second comparator. An amplifier stage generates a three-level PWM output signal using the outputs of the first and second comparators. A shared feedback path is used from the three-level PWM output signal.

主权项

1. An N-level class D amplifier circuit comprising:
a first comparator for comparing a first signal derived from an input voltage signal with a first reference signal that is a first triangular waveform; a second comparator for comparing a second signal derived from the input voltage signal with a second reference signal that is a second triangular waveform, wherein a phase relationship between the signals to the first comparator is phase shifted relative to a phase relationship between the signals to the second comparator; an amplifier stage for generating an N-level PWM output signal; a controller for controlling an amplifier stage based on the outputs of the first and second comparators; and a feedback path from the N-level PWM output signal; wherein the first triangular waveform is generated by a first triangular waveform generator and the second triangular waveform is 180 degrees out of phase with respect to the first triangular waveform and is generated by a second triangular waveform generator.