Texas Instruments ADS1x48EVM, User Manual, Page: 22 / 48

3.5.3.4 Connecting a 3-Wire RTD Using One IDAC and a High-Side R
REF
to J6 on the ADS1x48EVM
Figure 3-16 shows how to connect a 3-wire RTD using one IDAC and a high-side R
REF
configuration to J6.
REFP1
REFN1
AIN0
REFP1
REFN1
RTD_A
RTD_B
RTD_C
IEXC1
AIN3
AIN2
JP3
JP4
JP5
IEXC2 IEXC2
R
T
D
AIN1
IDA C
JP6
Figure 3-16. Connection Diagram for a 3-Wire RTD Using One IDAC and a High-Side R
REF
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.
ADS1x48EVM Overview www.ti.com
22 ADS1x48EVM Evaluation Module SBAU378A – SEPTEMBER 2021 – REVISED JANUARY 2022
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