A low current consumption delta-sigma modulator for body-implanted chip

Abstract

This paper presents a very low current consumption CMOS delta-sigma (/spl Delta//spl Sigma/) modulator with the aim of use for medical application, which takes advantage of low gate-source voltage by operating in the sub-threshold region. It is based on the switched-opamp (SOP) technique, which allows low voltage operation with a standard CMOS process. Single-ended SOP topology is adopted for the design to reduce the chip area. The /spl Delta//spl Sigma/ modulator has been designed using 0.35/spl mu/m standard CMOS technology. Even though using the single-ended SOP, 72dB dynamic range and 2.2/spl mu/A current consumption have been achieved for the /spl Delta//spl Sigma/ modulator.