Multiparameter Sensor Interface Circuit With Integrative Baseline/Offset Compensation By Switched-Capacitor Level Shifting/Balancing

Abstract

The proposed sensor interface circuit provides an integrative baseline/offset compensation to give higher adaptability and effectiveness for multiparameter sensing microsystems. Capacitive/resistive and voltage type sensors are dealt with and switched-capacitor-based circuits are mostly employed to facilitate integrative baseline/offset cancellation and interface various types of sensors. For integrative signal conditioning, sensor signals are first converted to voltage signals and then given rail-to-rail baseline compensation and fine offset cancellation of 0.7 mV/bit. At the same time, each interface circuit demonstrates a large total conversion gain (C: 194 mV/fF, R: 6260 mV/k Ω , V: 230 V/V) and a coefficient of determination (R 2 ) over 0.998, which indicates a high conversion linearity.