Patent ID: 6127885
Filing Date: 2000-10-03
Classification: H03F

Abstract:
A class D amplifier that amplifies an input signal to produce an analog output signal, comprising:a first circuit that produces a trapezoidal wave, at least one of the width and the duty cycle of which, and at least one of the rise and fall times of which, are dynamically modulated as a function of the input signal; anda second circuit that converts the trapezoidal wave into the analog output signal;wherein the first circuit comprises:a duty cycle modulator that dynamically modulates the duty cycle of a square wave as a function of the input signal; anda rate modulator that is responsive to the duty cycle modulator and to the input signal, to dynamically modulate at least one of the rise and fall times of the duty cycle modulated square wave, to produce the trapezoidal wave.