SBAS683B August 2014 – May 2020 ADS1120-Q1
PRODUCTION DATA.
Figure 75 and Figure 76 show the measurement results. The measurements are taken at TA = T(CJ) = 25°C. A system offset calibration is performed at T(TC) = 25°C, which translates to a V(TC) = 0 V when T(CJ) = 25°C. No gain calibration is implemented. The data in Figure 75 are taken using a precision voltage source as the input signal instead of a thermocouple. The respective temperature measurement error in Figure 76 is calculated from the data in Figure 75 using the NIST tables.
The design meets the required temperature measurement accuracy given in Table 17. Note that the measurement error shown in Figure 76 does not include the error of the thermocouple itself and the measurement error of the cold-junction temperature. Those two error sources are in general larger than 0.2°C and therefore, in many cases, dominate the overall system measurement accuracy.