Simple Digitizing Circuit for Resistive Sensors in π-Network Form

Abstract

This paper presents a detailed discussion on the design and performance verification of a digitizing circuit for a special type of resistive sensor - the resistive π-network model. The proposed circuit digitizes the output without requiring an additional ADC and boasts several positive features, such as a simple architecture with a single reference voltage, wide-range measurements, and good linearity. Moreover, the circuit can measure the input quantity independently of sensor elements and few other error sources. The paper clearly explains the working mechanism of the circuit and examines the impact of dominant error sources. Furthermore, it details the circuit’s performance through simulation and experimental studies. The maximum measured nonlinearity is lower than 0.14 % for a range of 40 dB. This demonstrates the linearizing-capability of the circuit for a wide range of inputs.