An integrated carbon dioxide sensor based on ratiometric thermal-conductivity measurement

Author

Cai, Z. ; van Veldhoven, R.H.M. ; Falepin, A. ; Suy, H. ; Sterckx, E. ; Makinwa, K.A.A. ; Pertijs, M.A.P.

Author_Institution

Delft Univ. of Technol., Delft, Netherlands

fYear

2015

fDate

21-25 June 2015

Firstpage

622

Lastpage

625

Abstract

This paper reports a CO₂ sensor intended for indoor air-quality sensing. Both the thermal-conductivity-based CO₂ transducer and its readout circuit have been realized in 0.16μm CMOS technology. The readout circuit, based on an incremental ΔΣ ADC, employs ratiometric measurements to circumvent the need for a stable power reference. The sensor achieves 228ppm (1σ) CO₂ resolution in a 70s measurement time, while consuming 11.2mW from a 1.8V supply. This resolution is 2x better than that of state-of-the-art thermal-conductivity-based CO₂ sensors, thus facilitating the realization of fully-integrated CO₂ sensors for air-quality monitoring, and a significant reduction in their cost (>10x) and volume (>100x) compared with the non-integrated CO₂ sensors.

Keywords

CMOS integrated circuits; air quality; carbon compounds; gas sensors; indoor environment; readout electronics; thermal conductivity; CMOS technology; CO₂; air-quality monitoring; delta sigma ADC; indoor air quality sensing; integrated carbon dioxide sensor; power 11.2 mW; ratiometric thermal-conductivity measurement; readout circuit; size 0.16 mum; voltage 1.8 V; Integrated circuits; Power measurement; Temperature measurement; Temperature sensors; Thermal conductivity; Thermal resistance; CMOS compatible; Carbon dioxide sensor; air quality monitoring; ratiometric; thermal conductivity;

fLanguage

English

Publisher

ieee

Conference_Titel

Solid-State Sensors, Actuators and Microsystems (TRANSDUCERS), 2015 Transducers - 2015 18th International Conference on

Conference_Location

Anchorage, AK

Type

conf

DOI

10.1109/TRANSDUCERS.2015.7181000

Filename

7181000