Paper Info
Title
A 296 nJ Energy-per-Measurement Relaxation Oscillator-Based Analog Front-End for Chemiresistive Sensors
Abstract
An energy-efficient, wide dynamic-range (DR) CMOS analog front-end (AFE) for chemiresistive sensors is presented. The circuit is specifically designed for the Metal Oxide (MOX) gas sensors, a special technology of chemiresistive sensors, broadly diffused in modern portable devices due to their low-cost and simplicity of use. Energy efficiency is mandatory for the AFE in order to prolong the battery life that supply these devices. The proposed circuit implements the resistance-to-time (R-to-T) conversion of the sensor's resistance by adopting a relaxation oscillator-based architecture. A limiting resistor in series with the sensor is introduced for reducing the circuit's energy-per-measurement (EpM), while mitigating the error due to the sensor's parasitic capacitance. The analysis of the circuit is presented with emphasis on the design trade-off between error due to the sensor's parasitic capacitance and power consumption on one side and read-out sensitivity on the other. The chip prototype is realized in AMS 0.35μm process and has been tested in the DR between 100Ω and 4.7MΩ with an accuracy less than 0.1% and a precision less than 0.029%. The efficacy of the presented AFE is proved by adopting the circuit in a real chemical environment with a commercial sensor. The proposed AFE shows a maximum EpM of 296nJ which is three times better than the state of the art.
Year
DOI
Venue
2021
10.1109/TCSI.2020.3047508
IEEE Transactions on Circuits and Systems I: Regular Papers
Keywords
DocType
Volume
CMOS sensor interface,gas sensors,MOX,sensor-controlled oscillator,read-out circuit,resistance-to-time,relaxation oscillator
Journal
68
Issue
ISSN
Citations 
3
1549-8328
3
PageRank 
References 
Authors
0.52
0
5
Name
Order
Citations
PageRank
Antonio Vincenzo Radogna141.34
Simonetta Capone230.86
Luca Francioso355.02
Pietro Aleardo Siciliano431.20
Stefano D'Amico512927.42