A low-power/low-noise readout circuit for integrated capacitive sensors

Author

Dimitropoulos, Panagiotis D. ; Karampatzakis, Dimitris P. ; Panagopoulos, Georgios D. ; Stamoulis, Georgios I.

Author_Institution

Inst. of Microelectron. & Microsystems, Swiss Fed. Inst. ofTechnology Lausanne

Volume

6

Issue

3

fYear

2006

fDate

6/1/2006 12:00:00 AM

Firstpage

755

Lastpage

769

Abstract

A switched-capacitor integrated system is presented in this work that attains sub-fF measurement resolution in integrated capacitive sensors, with 1.5-kHz bandwidth and 50-muW average power consumption in continuous function mode. The proposed design employs a pair of nonoverlapping clocks and an operational transconductance amplifier (OTA) that can be made as simple as a basic differential pair. The system exhibits 0.8% linearity error and 0.01 fF/degC temperature drift. It is appropriate for differential, absolute, and ratiometric capacitance measurements, and shows robustness against interconnection parasitics, transistor dimensional mismatch, and process variations, which are an important feature in the case of sensor-die CMOS postprocessing

Keywords

CMOS integrated circuits; capacitance measurement; capacitive sensors; low-power electronics; operational amplifiers; readout electronics; switched capacitor networks; 1.5 kHz; 50 muW; CMOS postprocessing; capacitance measurements; integrated capacitive sensors; operational transconductance amplifier; readout circuit; switched-capacitor integrated system; Bandwidth; Capacitive sensors; Clocks; Differential amplifiers; Energy consumption; Integrated circuit measurements; Linearity; Operational amplifiers; Power measurement; Transconductance; ASIC; CMOS analog IC; capacitive sensor; low power; switched capacitor;

fLanguage

English

Journal_Title

Sensors Journal, IEEE

Publisher

ieee

ISSN

1530-437X

Type

jour

DOI

10.1109/JSEN.2006.874439

Filename

1634429