TW269077B - Modulator - Google Patents

Abstract

A sigma-delta modulator comprises: one first backward integrator that receives one first error signal and supplies one output signal; one second backward integrator that receives one second error signal and supplies one output signal; one third backward integrator that receives one third error signal and supplies one output signal; one first forward integrator that receives the above third backward integrator and supplies one output signal; one A/D converter that quantizes output signal of the above first forward integrator and supplies one digital output signal; one D/A converter that converts digital output signal of the above A/D converter into one reference signal; the above first error signal formed by subtracting input signal from the above reference signal and one output signal, weighted via the first loop coefficient, of the above second backward integrator; the above second error signal formed by subtracting the output signal of above first backward integrator from one output signal, weighted via the second loop coefficient, of the above third backward integrator; and the above third error signal formed by subtracting the output signal of above second backward integrator from one output signal, weighted via the third loop coefficient, of the above first backward integrator.