A low-voltage low-power QFG-based Sigma-Delta modulator for electroencephalogram applications

A Sigma-Delta (SigmaDelta) modulator with 10 bits of resolution and only 55 nW power consumption for electroencephalogram (EEG) applications is presented. The overall modulator operates from 1.2 V using Quasi-Floating-Gates (QFG) based circuits. The system has been implemented in a standard 0.5-mum CMOS process. Post-layout simulations have been performed showing 70 dB of SNR with an oversampling ratio of 64.