SBAU378A September 2021 – January 2022 ADS1148 , ADS1248
Figure 3-18 shows how to connect a 3-wire RTD using two IDACs and a high-side RREF configuration to J6.
Figure 3-18 also shows that for this RTD configuration, the RTD is connected to REFN1, RTD_A, and RTD_B. Additionally, jumpers JP4, JP5, and JP6 are connected whereas jumper JP3 is disconnected. Finally, the AIN1 pin on the ADS1x48 is configured to be a current source and is used in conjunction with the IEXC1 current source, while the measurement is taken between AIN0 and AIN2. Table 3-5 summarizes the necessary connections and ADC configuration settings.