Measurement and parameter characterization of pseudo-resistor based CCIA for biomedical applications

Abstract

This paper performs the detailed analysis and measurement of a pseudo-resistor based CCIA used for bio-potential signal acquisition. The pseudo-resistor is implemented with MOS transistors operating in deep sub-threshold region, whose characteristic is not well-modeled in simulation. The resistor value versus control voltage and the effect of leakage current at OPAMP input node are discussed and characterized in this paper. The tested chip consumes 1.3µA from a 1-V supply, and the total integrated noise from 0.5 to 100 Hz is 3.26µVrms. It achieves a noise efficiency factor of 14.6.