Texas Instruments Incorporated
Ramp generator for multilevel class-D amplifiers

Abstract:

A multi-level ramp generator comprises three ramp generators. The first ramp generator generates a first ramp signal, comprising a sawtooth voltage waveform with a first common mode voltage and a first peak to peak voltage. The second ramp generator generates a second ramp signal, comprising a sawtooth voltage waveform with a second common mode voltage and a second peak-to-peak voltage. The third ramp generator generates a third ramp signal, comprising a sawtooth voltage waveform with a third common mode voltage and the second peak-to-peak voltage. The second and third ramp signals are in phase with each other and the first ramp signal is 180.degree. out of phase with the second and third ramp signals. In some implementations, each of the first, second, and third ramp generators comprise a respective delay locked loop and a respective voltage controlled oscillator.