A time-based technique for a resistive detector

The present paper describes a time-based technique for resistive detector. Thanks to the comparison with a reference resistance, the circuit easily compensate the baseline contribution, thus extending the dynamic range of the measurement. The implemented circuit is based on a resistance to time converter followed by a time comparator for signal comparison. Differently from existing time-based technique, the proposed approach allows increasing the sensitivity of the detection by increasing the time of the measurement. The circuit exhibits a measured resolution in the order of 20ppm with a nominal value of resistance of about 3MΩ while the maximum dynamic range is of about 40dB.