Title :
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
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;
Conference_Titel :
Solid-State Sensors, Actuators and Microsystems (TRANSDUCERS), 2015 Transducers - 2015 18th International Conference on
Conference_Location :
Anchorage, AK
DOI :
10.1109/TRANSDUCERS.2015.7181000
