INA821 datasheet(26/43 Pages) TI2

26 / 43 page

40 k

25 k

40 k

25 k

Overvoltage

Protection

Overvoltage

Protection

REF

+VS

V-

OUT

V+

-VS

-IN

+IN

RREF

INA818

SBOS894A – APRIL 2019 – REVISED JUNE 2019

www.ti.com

Product Folder Links: INA818

Submit Documentation Feedback

8.4 Device Functional Modes

The INA818 has a single functional mode and operates when the power-supply voltage is greater than 4.5 V

(±2.25 V). The maximum power-supply voltage for the INA818 is 36 V (±18 V.)

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. Customers should

validate and test their design implementation to confirm system functionality.

9.1 Application Information

9.1.1 Reference Pin

The output voltage of the INA818 is developed with respect to the voltage on the reference pin, REF. In dual-

supply operation, REF (pin 6) is connected to the low-impedance system ground. In single-supply operation,

offsetting the output signal to a precise midsupply level is useful (for example, 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 INA818 drives a single-supply ADC.

The voltage source applied to the reference pin must have a low output impedance. As shown in Figure 65, any

resistance at the reference pin (shown as RREF in Figure 65) is in series with an internal 40-kΩ resistor.

Figure 65. Parasitic Resistance Shown at the Reference Pin

INA821 Datasheet(PDF) 26 Page - Texas Instruments