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

Abstract

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 dB and is validated using skywater 130 nm CMOS technology. The obtained results show that the output signal frequency ranging from 38.61 kHz to 14.727 Hz is achieved, corresponding to resistance variations from 1 k ω to 49 M ω, with a simulated relative error of 0.999. The readout circuit exhibits a sensitivity of 2.66 Hz/M ω and a total power consumption of 402.05 μW. Additionally, the design features a highly compact layout with a footprint of 39003.5 μm2, making it suitable for area-constrained applications. © 2025 World Scientific Publishing Company.