High accuracy-wide range resistance measurement for thermistor sensors monitoring

Abstract

This paper describes an electronic circuitry conceived in order to measure electrical resistance values over an extended range covering up to six orders of magnitude and capable to assure a very high accuracy at any operating temperature, without any calibration or trimming and using only one precision reference resistor: the accuracy is limited up to 0.2% close to the measurement range boundaries. This circuitry has been specifically designed for temperature measurement using PTC and NTC thermistor sensors in particular for automotive applications. A multichannel architecture with a single reference resistance for ASIC integration is also presented.