arXiv · 2307.07822
Design Analysis and Experimental Validation of Relaxation Oscillator-Based Circuit for R-C Sensors
Abstract
Relaxation oscillator-based circuits are widely used for interfacing various resistive and capacitive sensors. The electrical equivalent of most resistive and capacitive sensors is represented using a parallel combination of resistor and capacitor. The relaxation oscillator-based circuits are not suitable for parallel R-C sensors. In this paper, we propose a modified circuit for parallel R-C sensors. The proposed relaxation oscillator-based circuit is based on a dual-slope and charge transfer technique to measure the resistance and capacitance of parallel R-C sensors separately. In addition, the paper provides a detailed analysis and design considerations for the oscillator design by taking into account the various sources of non-idealities. A method to reduce the error by using single-cycle averaging is also introduced. To verify the analyzed design criteria, the circuit is tested with multiple operational amplifiers with different non-idealities. Experimental results verify the performance of the proposed circuit. The circuit is tested for a range from 10 pF to 42 pF and 100 k$\Omega$ to 1 M$\Omega$ for parallel R-C sensors with an error of less than 1.5\%. The circuit is tested with a fabricated water-level sensor. The result confirms the efficacy of the proposed circuit.
Explore related subjects
Keep this discovery
Mohamad Idris Wani, Sadan Saquib Khan, Benish Jan, Meraj Ahmad, Maryam Shojaei Baghini, Laxmeesha Somappa, Shahid Malik. 2023-07-15. Design Analysis and Experimental Validation of Relaxation Oscillator-Based Circuit for R-C Sensors. https://arxiv.org/abs/2307.07822
Cite the original work for its findings. Save a collection to share your selection of sources.