A dual-slope resistance-to-digital (DSRDC) converter that accepts the resistance of a single-element resistive-type sensor as input and provides a direct digital output proportional to the parameter being sensed by the resistive-type sensor is presented in this paper. A high level of linearity and accuracy is achieved since the output of the DSRDC is dictated only by the magnitudes of a pair of dc reference voltages and the transformation constant of the sensor. Sensitivity analysis shows that the effect of circuit parameter variations on the output is minimal. Simulation studies and test results obtained on a prototype establish the efficacy of the proposed scheme.
Dr. Madhu Mohan N., George, B., and Kumar, V. J., “A Novel Dual-Slope Resistance-to-Digital Converter”, Instrumentation and Measurement, IEEE Transactions on, vol. 59, pp. 1013-1018, 2010.