Title :
A micropower front-end interface for differential-capacitive sensor systems
Author :
Constandinou, Timothy G. ; Georgiou, Julius ; Toumazou, Chris
Author_Institution :
ECE Dept., Univ. of Cyprus, Nicosia
Abstract :
This papers presents a front-end circuit for interfacing to differential capacitive sensors, including certain micro- electromechanical systems (MEMS). The system combines a self- resetting, biphasic integrator with a difference timer, producing a word parallel output representing the differential capacitance. The measurable capacitance range is tunable by means of an input current bias and system clock frequency. For an input bias of lOnA and system clock of 128 KHz, the measurable capacitance range is +/-5 pF (to 8 bit resolution) consuming below 26 muW total system power.
Keywords :
capacitance; capacitive sensors; clocks; microsensors; biphasic integrator; difference timer; differential capacitance; differential-capacitive sensor systems; input current bias; microelectromechanical systems; micropower front-end interface; system clock frequency; Capacitance measurement; Capacitive sensors; Clocks; Current measurement; Electromechanical systems; Frequency measurement; Integrated circuit measurements; Micromechanical devices; Sensor systems; Tunable circuits and devices; capacitive sensor interface; differential capacitance; dual slope converter; integrate and fire; low power;
Conference_Titel :
Circuits and Systems, 2008. ISCAS 2008. IEEE International Symposium on
Conference_Location :
Seattle, WA
Print_ISBN :
978-1-4244-1683-7
Electronic_ISBN :
978-1-4244-1684-4
DOI :
10.1109/ISCAS.2008.4541957
