Patent ID: 7659778

Claim:
A circuit for amplification, comprising: a class D controller that is arranged to receive a class D amplifier input signal and to provide a class D controller output signal, wherein the class D controller includes: an interpolator that is arranged to receive a digital signal, and to provide a an interpolator output signal by interpolating the digital signal, wherein the digital signal is based, at least in part, on the class D amplifier input signal; and a sample rate converter, including: a poly-phase interpolator from which two adjacent phases are computed per output sample of the poly-phase interpolator, wherein the poly-phase interpolator is arranged to receive the interpolator output signal as an input; a linear interpolator that is arranged to perform linear interpolation between the two adjacent phases; and a phase control circuit that is arranged to control the poly-phase interpolator and the linear interpolator such that the linear interpolator outputs a sample rate converter output signal such that the sampling rate of the sample rate converter output signal has a sampling rate that is greater than a sampling rate of the interpolator output signal by an SRC factor, wherein the SRC factor is greater than one and less than two, and wherein the class D controller output signal is based, at least in part, on the sample rate converter output signal.