Advanced Analog Interface Circuit for Four-Wire Resistive Sensors

This paper presents the design and development of an advanced analog interface circuit tailored for four-wire resistive sensors, with the objective of enhancing measurement accuracy and mitigating the effects of lead resistances. The proposed circuit utilizes operational amplifiers and an analog switch to establish a constant current through the sensor, thereby minimizing self-heating errors and effectively compensating for lead resistance mismatches. Extensive experimental validation is performed across a temperature range from −100 °C to 850 °C, demonstrating a maximum nonlinearity error of 0.25% and a relative error of 0.26%, both within acceptable industrial limits. The performance of the circuit confirms its suitability for critical applications in automotive, aerospace, and biomedical domains. Comparative analysis with existing interface solutions reveals the proposed circuit's advantages in terms of reduced component count, single-cycle operation, and improved measurement precision. Overall, this paper offers a robust and efficient analog solution for accurate resistance measurement in high-performance sensor systems.