SBAU378A September 2021 – January 2022 ADS1148 , ADS1248
Figure 3-16 shows how to connect a 3-wire RTD using one IDAC and a high-side RREF configuration to J6.
Figure 3-16 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. Moreover, the AIN1 pin on the ADS1x48 is configured to be a current source. Finally, this specific configuration requires two measurements for lead-wire cancellation: the first is between AIN0 and AIN2 and, the second is between AIN2 and AIN3. Table 3-5 summarizes the necessary connections and ADC configuration settings.