An Area-Efficient with High-Dynamic Range Readout Circuit for Resistive Gas Sensors

The growing demand for accurate environmental monitoring and air quality control has highlighted the importance of highly sensitive and reliable gas sensors. These gas sensors typically exhibit a wide range of resistance variations, necessitating a readout circuit with a broad dynamic range to accurately convert the sensor signal into a digital output. Therefore, this research aims to address these challenges by developing an area-efficient and high-dynamic range readout circuit for resistive gas sensors, utilizing a resistance-to-frequency conversion approach. The proposed readout circuit achieves an impressive high dynamic range of 142[Formula: see text]dB and is validated using skywater 130[Formula: see text]nm CMOS technology. The obtained results show that the output signal frequency ranging from 38.61[Formula: see text]kHz to 14.727[Formula: see text]Hz is achieved, corresponding to resistance variations from 1[Formula: see text]k[Formula: see text] to 49[Formula: see text]M[Formula: see text], with a simulated relative error of 0.999. The readout circuit exhibits a sensitivity of 2.66[Formula: see text]Hz/M[Formula: see text] and a total power consumption of 402.05[Formula: see text] [Formula: see text]W. Additionally, the design features a highly compact layout with a footprint of 39003.5[Formula: see text] [Formula: see text]m 2 , making it suitable for area-constrained applications.