Figure 3-20. Connection Diagram For A 4-Wire Rtd Using A High-Side R; Table 3-5. Ads1X48Evm Settings For Different Rtd Types - Texas Instruments ADS1x48EVM User Manual

ADS1x48EVM Overview
3.5.3.8 Connecting a 4-Wire RTD Using a High-Side R
Figure 3-20 shows how to connect a 4-wire RTD using a high-side R

Figure 3-20. Connection Diagram for a 4-Wire RTD Using a High-Side R

Figure 3-20 also shows that for this RTD configuration, the RTD is connected to REFN1, RTD_A, RTD_B, and
RTD_C. Additionally, jumpers JP5 and JP6 are connected whereas jumpers JP3 and JP4 are disconnected.
Finally, the AIN1 pin on the ADS1x48 is configured to be a current source and the measurement is taken
between AIN2 and AIN3.
3.5.3.9 Summary of ADS1x48EVM RTD Configuration Settings
Table 3-5 summarizes the required IDAC, jumper, and analog input channel settings to measure each RTD
configuration using the ADS1x48EVM.
RTD No. of IDACs
1
2-wire
1
1
3-wire 1
2
2
1
4-wire
1
(1) First measurement.
(2) Second measurement.
26 ADS1x48EVM Evaluation Module
REFP1
REFN1
RTD_A
RTD_B
RTD_C
Table 3-5 summarizes the necessary connections and ADC configuration settings.

Table 3-5. ADS1x48EVM Settings for Different RTD Types

R IDAC Channels
REF
Low-side IEXC1
High-side AIN1
Low-side IEXC1
High-side AIN1
Low-side IEXC1, IEXC2
High-side AIN1, IEXC2
Low-side IEXC1
High-side AIN1
Copyright © 2022 Texas Instruments Incorporated
to J6 on the ADS1x48EVM
REF
configuration to J6.
REF
IDA C
JP6
AIN1
REFP1
REFN1
AIN0
JP3
IEXC2 IEXC2
AIN2
AIN3
JP4
IEXC1
JP5
JP3 JP4 JP5 JP6
On On Off Off
Off On On On
On On Off Off
Off On On On
On On Off Off
Off On On On
On Off Off Off
Off Off On On
SBAU378A – SEPTEMBER 2021 – REVISED JANUARY 2022
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REF
AINP AINN
AIN3 AIN1
AIN0 AIN3
(1) (1)
AIN3 AIN2
(2) (2)
AIN2 AIN1
(1) (1)
AIN0 AIN2
(2) (2)
AIN2 AIN3
AIN3 AIN2
AIN0 AIN2
AIN3 AIN2
AIN2 AIN3
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