Title :
A readout circuit with wide dynamic range for differential capacitive sensing applications
Author :
Aezinia, Fatemeh ; Bahreyni, B.
Author_Institution :
Sch. of Eng. Sci., Simon Fraser Univ., Burnaby, BC, Canada
Abstract :
This paper presents a compact, low power, digitally assisted differential capacitive-sensing readout circuit. It utilizes digital design and switch-based synchronous demodulator to reduce area and power consumption while improving the robustness of the system by diminishing the effects of interfering signals. To broaden the sensing range of the system, the simple implementation of a closed-loop configuration is employed to dynamically adjust the gain. This circuit is designed, analyzed, and laid out in a standard 0.35 μm CMOS technology from Austria Microsystems. Post-layout simulation results reveal that the proposed circuit is capable of resolving a minimum of 1fF changes in input capacitance under test.
Keywords :
CMOS integrated circuits; capacitive sensors; circuit simulation; closed loop systems; demodulators; integrated circuit testing; power consumption; readout electronics; Austria Microsystems; CMOS technology; circuit design; circuit test; closed-loop configuration; compact low power differential capacitive-sensing readout circuit; differential capacitive sensing application; digital design; digitally assisted differential capacitive-sensing readout circuit; input capacitance; interfering signal; post-layout simulation; power consumption; sensing range; size 0.35 mum; switch-based synchronous demodulator; system robustness; wide dynamic range; Capacitance; Capacitive sensors; Demodulation; Dynamic range; Oscillators; Voltage control; Capacitive sensing; feedback loop; interface circuit;
Conference_Titel :
Electrical and Computer Engineering (CCECE), 2013 26th Annual IEEE Canadian Conference on
Conference_Location :
Regina, SK
Print_ISBN :
978-1-4799-0031-2
Electronic_ISBN :
0840-7789
DOI :
10.1109/CCECE.2013.6567799
