Texas Instruments ADS1x48EVM, User Manual, Page: 9 / 48

3.2 Voltage Reference Options
The ADS1x48 is a highly flexible ADC that can accept multiple voltage reference (VREF) options. First, the
ADS1x48 integrates a low-noise, 2.048-V reference to help reduce overall component count. Moreover, this
internal VREF voltage is supplied externally via the ADS1x48 REFOUT pin and is available on terminal block J5.
The ADS1x48 also has two sets of differential VREF inputs defined as REFP0, REFN0 and REFP1, REFN1. All
of these options are selected via the MUX1 register in the ADS1x48.
The ADS1x48EVM supports four different VREF options to offer maximum flexibility. Table 3-1 details these four
options. Figure 3-3 shows the location of each VREF option (highlighted in yellow) as well as each VREF test
point (highlighted in red).
Table 3-1. Summary of ADS1x48EVM VREF Options
VREF Mode
VREF Input
Channel
Voltage Location Test Point Comment
Internal — 2.048 V U3
Output on J5
(REFOUT)
—
External
REF5025 REFP0, REFN0 2.5 V U2
Output on J5
(REF5025)
—
Ratiometric REFP1, REFN1 Variable R11 REFP1, REFN1
Used for RTD
measurements
User-provided REFP1, REFN1 Variable
J6 (REFP1,
REFN1)
REFP1, REFN1 Remove R11
Figure 3-3. ADS1x48EVM VREF Options (Yellow) and Test Points (Red)
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SBAU378A – SEPTEMBER 2021 – REVISED JANUARY 2022
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ADS1x48EVM Evaluation Module 9
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