A Simple and Accurate Analog Front-End Circuit for Three-Wire Resistive Sensors

Abstract

This article introduces an innovative and economical analog front-end circuit designed for the precise measurement of resistance in remote resistive sensors. The presented circuit, which incorporates only two op-amps, switches, a single reference voltage, a few resistors, and a capacitor, provides a more straightforward solution compared to the existing approaches. By utilizing a control signal, the circuit ensures accurate sensor readings while minimizing the impact of wire resistances and other error sources. The comprehensive theoretical analysis and experimental validation show that the circuit maintains high linearity, low error rates, and effective noise reduction. In comparison to traditional methods, the proposed circuit demonstrates superior performance, with a maximum nonlinearity of 0.06% and a relative error of 0.04%, making it a reliable option for applications requiring remote sensor connectivity. Additionally, the simplicity and affordability of the circuit design make it an appealing solution for integrating resistive sensors in various industrial and research applications.