Self-Controlled Robust Digital Readout Circuit for Resistance Measurement: Enhancing Immunity to Circuit Nonidealities

This paper proposes a self-controlled digital readout circuit for resistance measurement. The circuit offers numerous advantages, such as independence from circuit nonidealities, the elimination of the need for a control unit, a wide range of measurements, etc. Mathematical proofs are provided within the paper to demonstrate these benefits. The performance of the circuit is validated through simulation and an extensive experimental study. The results reveal a maximum nonlinearity of 0.2 % and a relative error of 0.4 % for the proposed circuit. Additionally, a comparative study is conducted to compare the results and advantageous features of the proposed circuit with those of existing digital readout circuits. Through various analyses, it is determined that the proposed circuit outperforms the existing alternatives. As a result, the proposed circuit is highly recommended for near-sensor applications.

I. INTRODUCTION

Temperature measurement plays a crucial role in various industries, including aerospace [1], automotive [2], and biomedical [3]. For instance, in the biomedical field, Resistance Temperature Detectors (RTDs) are utilized in breathing analysis and monitoring systems. These RTD sensors exhibit a linear relationship between resistance and temperature [4]. To accurately measure these changes in resistance, readout circuits are indispensable. Digital readout circuits have gained popularity due to their ability to eliminate the need for an Analog-to-Digital Converter (ADC). This paper introduces a digital readout circuit specifically designed for the resistance measurement of temperature sensors.