Integrated interface circuit with multiplexed input and digital output for a 5 × 5 SnO2 thick film gas-sensor matrix

This paper presents the design and experimental results for a 5 × 5 tin-oxide gas-sensor array system with particular focus on the employed multiplexed-analog-input 0.35 μm CMOS interface circuit chip. This interface circuit reads the electrical signal of all the elements of the array in time sharing by means of a solid-state selector, actually exploiting a row-column query technique and provides digital output to a dedicated LabView™ Software. The proposed system shows very promising properties in terms of data redundancy in order to improve the signal-to-noise-ratio in electronic nosing and for future studies about the influence of gas consumption rate over the metal oxide surface for a 2D array. Sensors fabrication details, electronic interface performance characterization and chemical measurements results are also reported for completeness.