A Fully Integrated Gas Detection System With Programmable Heating Voltage And Digital Output Rate For Gas Sensor Array

In this paper, a gas detection system for 2 x 2 MEMS gas sensor array is proposed. It has multiple measurement channels, programmable heating voltage, programmable measurement time, 24-bit digital output with 8-bit accuracy, wide measurement range and high linearity. The chip is realized in SMIC 180 nm complementary metal oxide semiconductortechnologywith an area of 1.58mmx1.66mm. The result of the fixed resistance measurement shows that the linearity of the resistance ranges (200 Omega-200 K Omega, 200 Omega 500K Omega, 200 Omega-1M Omega, 200 Omega-2M Omega, 200 Omega-5M Omega, and 200 Omega-10M Omega) are all less than 1% at different measurement time intervals. At 1 s measurement time, the circuit has a wide detectable resistance range (200 Omega-10M Omega), and high linearity of 0.3047%. The experimental results combined with the resistive MEMS gas sensor array show that the circuit has a good detection effect in the gas concentration range (0 ppm-340 ppm), and can even detect the change of gas concentration at a low concentration of 0.1 ppm. Moreover, the system can detect different responses of the same sensor at different heating voltages.