A Portable Low-Voltage Low-Power ppm-Level Resistive Sensor Measurement System

Objective: The objective of the paper is to present a novel systematic approach for the design and development of a portable, low-voltage low-power resistive sensor measurement system with high sensitivity. The goal of the proposed system is to be able to measure the Delta R/R-s for a wide range of baseline resistance of sensor Rs (1 k Omega to 1 M Omega i.e. 3 orders of magnitude) with high resolution and programmable sensitivity. Method: An auto-calibrated resistive sensor interface using a novel half-bridge based circuit is presented. The square-wave excitation and squarewave demodulation technique are utilised to reduce the power consumption of the proposed technique. Moreover, the sensitivity of the system is fully auto-calibrated for a wide range of base resistors. Results: With a supply voltage of 3.3 V and bandwidth of 10 Hz, the developed system is able to measure a minimum Delta R/R-s of about 20 ppm for 100 k Omega base resistance. Overall, the power consumption of the developed system is 36.3 mW (for four channels). Significance: The system is useful for low-voltage low-power sensor nodes as a highly sensitive readout for the resistive sensor arrays. In addition, the developed system is useful for the stain sensors in the development of flexible hybrid electronics for wearable applications.

Automated summary

The paper presents a novel approach for the design of a portable, low-voltage low-power resistive sensor measurement system with high sensitivity. The proposed system utilizes a half-bridge based circuit for auto-calibrated resistive sensor interface, and reduces power consumption using square-wave excitation and demodulation. The system has the ability to measure Delta R/R-s for a wide range of baseline resistance with high resolution and programmable sensitivity. The results show that the developed system performs well in measuring minimum Delta R/R-s for different base resistors. The system is significant for low-voltage low-power sensor nodes and flexible hybrid electronics for wearable applications.