Abstract
Two electronic interfaces performing a differential (or ratiometric) sensor capacitance to voltage conversion are here presented. The output signal is proportional to the measurand variation x. The two read-out circuits differ themselves in their input stage: the first has an input current-to-voltage conversion, while the second one employs an input voltage source. Both of the solutions utilize commercial second generation current conveyors (CCIIs) as active blocks, in particular AD844. Theoretical analysis, simulated and experimental results have shown a good accuracy. Considering a capacitance variation due to the relative distance change, interface sensitivity (S) and resolution (res) values are constant and satisfactory: for the first solution, S = 8.54 V/μm and res = 674 pm (capacitance resolution value is 89.85 fF, that is −79 dB), while, for the second one, S = 8.13 V/μm and res = 814 pm (capacitance resolution value is 108.5 fF, that is −77 dB).
Access this chapter
Tax calculation will be finalised at checkout
Purchases are for personal use only
References
L.K. Baxter, Capacitive sensors: design and applications, vol. 1 (John Wiley & Sons, New York, 1996)
N. Yazdi, H. Kulah, K. Najafi, Precision readout circuits for capacitive microaccelerometers. Proc. IEEE Sens. 24–27 (2004)
M.N. Horenstein, J.A. Perreault, T.G. Bifano, Differential capacitive position sensor for planar MEMS structures with vertical motion. Sens. Actuators 80, 53–61 (2000)
R.E. Oosterbroek, T.S.J. Limmerink, J.W. Berenshot, G.J.M. Krijnen, M.C. Elwenspoek, A. van den Berg, A micromachined pressure/flow-sensor. Sens. Actuators 77, 167–177 (1999)
B. George, V.J. Kumar, Switched capacitor signal conditioning for differential capacitive sensors. IEEE Trans. Instrum. Measur. 56, 913–917 (2007)
Q. Jia, G. Meijer, X. Li, C. Guan, An integrated interface for grounded capacitive sensors, in Proceedings of the 4th IEEE Sensors Conference. Irvine. Oct 2005, pp. 4–5
T.G. Constandinou, J. Georgiou, C. Toumazou, A micropower front-end interface for differential-capacitive sensor systems, in Proceedings of the IEEE International Symposium on Circuits and Systems. Seattle. May 2008, pp. 2474–2477
N.M. Mohan, A.R. Shet, S. Kedarnath, V.J. Kumar, Digital converter for differential capacitive sensors. IEEE Trans. Instrum. Meas. 57, 2576–2581 (2008)
K. Mochizuki, K. Watanabe, T. Masuda, A high-accuracy high-speed signal processing circuit of differential-capacitance transducers. IEEE Trans. Instrum. Meas. 47, 1244–1247 (1998)
T. Singh, T. Sæther, T. Ytterdal, Current-mode capacitive sensor interface circuit with single-ended to differential output capability. IEEE Trans. Instrum. Meas. 58, 3914–3920 (2009)
G. Ferri, F.R. Parente, V. Stornelli, G. Pennazza, M. Santonico, A. D’Amico, A standard CMOS technology fully-analog differential capacitance sensor front-end, in Proceedings of the International Workshop on Advanced Sensor Interface. Gallipoli. June 2015, pp. 152–157
G. Ferri, N.C. Guerrini, Low-voltage low-power CMOS current-conveyors (Kluwer Academic Publisher, Boston, 2003)
G. Ferri, A. De Marcellis, C. Di Carlo, V. Stornelli, A. Flammini, A. Depari, D. Marioli, E. Sisinni, A CCII-based low-voltage low-power read-out circuit for DC-excited resistive gas sensors. IEEE Sens. J. 9, 2035–2041 (2009)
G. Ferri, V. Stornelli, A. di Simone, A CCII-based high impedance input stage for biomedical applications. J. Circuits Syst. Comput. 20(8), 1441–1447 (2011)
V. Stornelli, G. Ferri, A 0.18 μm CMOS DDCCII for portable LV-LP filters. Radioengineering 22(2), 434–439 (2013)
C. Falconi, G. Ferri, V. Stornelli, A. De Marcellis, D. Mazzieri, A. D’Amico, Current-mode high-accuracy high-precision CMOS amplifiers. IEEE Trans. Circuits Syst. II 55(5), 394–398 (2008)
A. De Marcellis, G. Ferri, Analog Circuits and Systems for Voltage-Mode and Current-Mode Sensor Interfacing Applications (Springer, 2011)
G. Bonfini, A.S. Brogna, C. Garbossa, L. Colombini, M. Bacci, S. Chicca, F. Bigongiari, N.C. Guerrini, G. Ferri, An ultra low power switched opamp-based 10-bit integrated ADC for implantable biomedical applications. IEEE Trans. Circuits Syst. 51, 174–177 (2004)
Author information
Authors and Affiliations
Corresponding author
Editor information
Editors and Affiliations
Rights and permissions
Copyright information
© 2018 Springer International Publishing AG
About this paper
Cite this paper
Ferri, G., Parente, F.R., Stornelli, V., Barile, G., Pennazza, G., Santonico, M. (2018). CCII-Based Linear Ratiometric Capacitive Sensing by Analog Read-Out Circuits. In: Andò, B., Baldini, F., Di Natale, C., Marrazza, G., Siciliano, P. (eds) Sensors. CNS 2016. Lecture Notes in Electrical Engineering, vol 431. Springer, Cham. https://doi.org/10.1007/978-3-319-55077-0_50
Download citation
DOI: https://doi.org/10.1007/978-3-319-55077-0_50
Published:
Publisher Name: Springer, Cham
Print ISBN: 978-3-319-55076-3
Online ISBN: 978-3-319-55077-0
eBook Packages: EngineeringEngineering (R0)