9 Application and Implementation

Note

Information in the following applications sections is not part of the TI component specification,

and TI does not warrant its accuracy or completeness. TI’s customers are responsible for

determining suitability of components for their purposes, as well as validating and testing their design

implementation to confirm system functionality.

9.1 Application Information

9.1.1 Reference Pin

The output voltage of the INA849 is developed with respect to the voltage on reference pin REF.

Use the REF pin to offset the output signal to a precise midsupply level. Typically, this offset is 2.5 V in a

5-V supply environment. To accomplish this level shift, a voltage source must be connected to the REF pin to

level-shift the output so that the INA849 drives a single-supply analog-to-digital converter (ADC).

For dual-supply operation, the reference pin is typically connected to the low-impedance system ground.

The voltage source applied to the reference pin must have a low output impedance. As shown in Figure 9-1,

imbalance in the four resistors of the internal difference amplifier.

+

±

+

±

+

±

5 k

3 k

5 k

5 k

5 k

3 k

íRG

REF

+VS

OUT

+V

S

íVS

íIN

+IN

+RG

R

G

R1

C3

C2

C1

R2

Figure 9-1. Parasitic Resistance Shown at the Reference Pin

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INA849

SBOS945B – NOVEMBER 2020 – REVISED APRIL 2021

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