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 INA351 is developed with respect to the voltage on the reference pin (REF). Often in

dual-supply operation, REF pin connects to the system ground. However, In single-supply operation, offsetting

the output signal to a precise mid-supply level is useful and required (for example, 2.75-V in a 5.5-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 INA can drive a single-supply ADC. Traditionally, this is accomplished using an external

reference buffer as shown in Figure 9-1.

INA351 has an integrated reference buffer amplifier configured in unity gain, voltage follower configuration

internal to the amplifier as shown in the Simplified Internal Schematic. This allows INA351 to be directly

connected to a resistive divider without any need for an external refernce buffer amplifier as shown in Figure 9-2.

+IN

–IN

INA350

5 V

TLV9041

100 k

5 V

1

F

5 V

100 k

OUT

Figure 9-1. INA350 / Traditional INA - External reference buffer required

+IN

–IN

5 V

OUT

100 k

1 µF

INA351

5 V

100 k

Figure 9-2. INA351 with integrated reference buffer - No external reference buffer required

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INA351

SBOSAD5 – DECEMBER 2022

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