Design and Simulation of Sigma Delta ADC Using VHDL

Abstract- There is two main parts of Sigma-delta ADC: analog modulator and digital filter, the performance of modulator determines the performance of sigma-delta ADC, so the design of modulator is very important. This paper introduces the principle of sigma-delta ADC modulator with high accuracy and the applied over sampling technique, noise shaping technique and multi-bit quantize technique. This paper determines the design scheme of modulator—second orders CIFF (Cascade of integrators, feed forward form) structure and it makes the behavior level verification for this scheme by VHDL AMS. Index Terms — Sigma-delta ADC; modulator; over sampling; noise shaping I