Modeling of a Second Order Sigma-Delta Modulator with Imperfections

Abdelghani Dendouga, Nour-Eddine Bouguechal, Souhil Kouda and Samir Barra Advanced Electronic Laboratory, Batna University, Algeria 05 Avenue Chahid Boukhlouf, 05000 BATNA, ALGERIE E-mail: [email protected] Abstract—Sigma delta modulators (ΣΔMs) form part of the core of today’s mixed-signal designs. The ongoing research on these devices shows the potential of ΣΔ data converters as a promising candidate for high-speed, high-resolution, and low-power mixed-signal interfaces. This work presents a new accurate behavioral model of a second order law-pass Switched Capacitor (SC) Sigma-Delta modulator. Our main contribution consists to predict the effect of almost sources of noise on the operation of sigma delta modulator such as non idealities of op-amp and switches. The purpose of this work is the presentation of a behavioral model of a second order switched capacitor ΣΔ modulator considering (Error due to Clock Jitter, Thermal noise Amplifier Noise, Amplifier Slew-Rate, Non linearity of amplifiers, Gain error, Charge Injection, Clock Feed-through, and Nonlinear onresistance). A comparison between the use of MOS switches and the use transmission gate switches use is analyzed.