Patent ID: 6661363
Filing Date: 2003-12-09
Classification: H03M

Abstract:
An adaptive sigma delta modulator comprising:a) a first input stage that produces a difference signal representing the difference between an analog input signal x(n) and a first analog feedback signal z(n), the amplitude of the analog input signal x(n) within a first range [âˆ’a, +a]; b) a first accumulator stage that produces a first accumulated signal representing an accumulation of the difference signal; c) a first quantization stage that produces a first quantized digital signal y0(n) representing the first accumulated signal; d) a first adaptation stage, that based on the first quantized digital signal y0(n) produces a first digital output signal z0(n); and e) a first digital-to-analog converter stage that converts the first digital output signal z0(n) to the first analog feedback signal z(n); wherein the first adaptation stage tends to keep the instantaneous magnitude of the first analog feedback signal z(n) within the first range [âˆ’a, +a] and greater than the analog input signal's x(n) instantaneous magnitude.