DocumentCode :
1809638
Title :
An energy-efficient 15-bit capacitive sensor interface
Author :
Tan, Zhichao ; Pertijs, Michiel A P ; Meijer, Gerard C M
Author_Institution :
Electron. Instrum. Lab., Delft Univ. of Technol., Delft, Netherlands
fYear :
2011
fDate :
12-16 Sept. 2011
Firstpage :
283
Lastpage :
286
Abstract :
This paper presents a period-modulator based capacitive sensor interface implemented using energy-efficient building blocks. The integrator in the modulator is based on a current-efficient telescopic OTA, whose limited output swing is accommodated using negative feedback loops. The use of a low-power comparator is enabled by eliminating errors associated with its propagation time using auto-calibration. The interface has been implemented in 0.35 μm standard CMOS technology. Experimental results show that for a capacitance range of 6.8 pF, the interface achieves 15-bit resolution and 12-bit linearity within a measurement time of 7.6 ms, while consuming only 64 μA from a 3.3 V power supply. Compared to previous work with similar performance, this represents a significant improvement in energy efficiency.
Keywords :
CMOS integrated circuits; capacitive sensors; comparators (circuits); modulators; operational amplifiers; CMOS technology; auto-calibration; capacitive sensor interface; current 64 muA; current-efficient telescopic OTA; energy-efficient building blocks; integrator; low-power comparator; negative feedback loops; period modulator; propagation time; size 0.35 mum; time 7.6 ms; voltage 3.3 V; word length 12 bit; word length 15 bit; Capacitance; Capacitive sensors; Capacitors; Energy efficiency; Semiconductor device measurement; Time measurement;
fLanguage :
English
Publisher :
ieee
Conference_Titel :
ESSCIRC (ESSCIRC), 2011 Proceedings of the
Conference_Location :
Helsinki
ISSN :
1930-8833
Print_ISBN :
978-1-4577-0703-2
Electronic_ISBN :
1930-8833
Type :
conf
DOI :
10.1109/ESSCIRC.2011.6044962
Filename :
6044962
Link To Document :
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