Accumulator for adaptive sigma-delta modulation

摘要

A system and method for adaptive sigma-delta modulation. The system includes a input stage that produces a difference signal representing the difference between an analog input signal x(n) and a analog feedback signal z(n), the amplitude of the analog input signal x(n) within a first range [-a, +a]. An accumulator stage produces a accumulated signal that is a function of an accumulation of the difference signal, the accumulator stage transforming the accumulation of the difference signal so as to increase average magnitude while ensuring instantaneous magnitude does not exceed a predetermined value. A quantization stage produces a quantized digital signal y₀(n) representing the accumulated signal. Based on the quantized digital signal y₀(n), a adaptation stage produces a digital output signal z₀(n), which is converted to the analog feedback signal z(n) by a digital-to-analog converter stage.