Mixed-mode Method Used for Pt100 Static Transfer Function Linearization

Abstract Pt100 is a resistance temperature detector characterized by relatively linear resistance/temperature relationship in narrow range. However, the sensor shows certain degree of static transfer function nonlinearity 4.42 % range between −200 °C and 850 °C, which unacceptable for some applications. As solution to this problem, mixed-mode linearization method based on special dual-stage piecewise ADC design proposed paper. The first stage performed with low-complex low-power flash novel sequential design. novelty reflected fact that number employed comparators equal resolution. second delta-sigma differential input reference. Using 6-bit 24-bit ADC, error reduced 2.6·10 −3 %, °C. Two more ranges are examined, following results obtained: 0 500 from 1.99 5·10 −4 while −50 150 0.755 2.15·10 %.