Fractional-Order Dual-Slope Integral Fast Analog-to-Digital Converter with High Sensitivity

Abstract

The dual-slope integral analog-to-digital converter is widely used in low-speed, high-precision measurement owing to its high precision and strong resistance on crosstalk interference. To meet the requirements of higher accuracy and faster measurement, the integral sensitivity and conversion speed of the dual-slope integral analog-to-digital converter must be improved. Therefore, based on fractional-order calculus, we propose a fractional-order dual-slope integral analog-to-digital converter. First, constant-current charging curves were provided to explain the source of the idea of the fractional-order dual-slope integral analog-to-digital converter. Then, the working principle of the fractional-order dual-slope integral analog-to-digital converter is described in detail. The calculation formula of analog-to-digital conversion is derived and analyzed. Moreover, the relationship of the voltage-measurement error with the operation-order error of the fractor and the reference voltage error is theoretically derived. Furthermore, we theoretically analyze the resistance of the proposed analog-to-digital converter to crosstalk interference, as well as the requirements for the first fractional integral time when crosstalk interference is suppressed. Specifically, we prove that the proposed analog-to-digital converter has a higher sensitivity and conversion speed than the classical converter, and we provide a quantitative calculation formula.