Patent ID: 6466087
Filing Date: 2002-10-15
Classification: H03F

Abstract:
A signal path, comprising:a sigma-delta modulator (SDM) for receiving an N-bit digital signal; a pulse width modulator (PWM) coupled to an output of said SDM for receiving an n-bit digital signal output therefrom, said PWM having an output for outputting a pulse width modulated waveform signal in accordance with said n-bit digital signal; a PWM waveform signal correction circuit coupled to an output of said PWM and outputting a corrected pulse width modulated waveform signal; a class D switching stage coupled to an output of said PWM waveform correction circuit for being driven by said corrected pulse width modulated waveform signal and providing a signal path output for driving a load; and an error measurement block having a first input coupled to said output of said switching stage, a second input coupled to said output of said PWM, and an output coupled to a correction input of said PWM waveform signal correction circuit; said error measurement block obtaining a difference between a first signal appearing at said first input and a second signal appearing at said second input and outputting at said output a digital correction signal that indicates a sign of the difference between said first input signal and second input signal.