:

G

49.4 k

G

1

R

+

±

+

±

+

±

10 k

24.7 k

10 k

10 k

10 k

24.7 k

Overvoltage

Protection

Overvoltage

Protection

RG

REF

+VS

V-

OUT

V+

-VS

-IN

+IN

:

G

49.4 k

G

1

R

O

IN

IN

REF

V

G V

V

V

Copyright © 2017, Texas Instruments Incorporated

RG

18

INA821

SBOS893 – AUGUST 2018

www.ti.com

Product Folder Links: INA821

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Copyright © 2018, Texas Instruments Incorporated

8.3 Feature Description

8.3.1 Setting the Gain

pins (pins 1 and 8).

Figure 51. Simplified Diagram of the INA821 With Gain and Output Equations

(1)

Table 1 lists several commonly used gains and resistor values. The 49.4-k

Ω term in Equation 1 is a result of the

sum of the two internal 24.7-kΩ feedback resistors. These on-chip resistors are laser-trimmed to accurate

absolute values. The accuracy and temperature coefficients of these resistors are included in the gain accuracy

and drift specifications of the INA821.

Table 1. Commonly-Used Gains and Resistor Values

DESIRED GAIN

1

NC

NC

2

49.4 k

49.9 k

5

12.35 k

12.4 k

10

5.489 k

5.49 k

20

2.600 k

2.61 k

50

1.008 k

1 k

100

499

499

200

248

249

500

99

100

1000

49.4

49.9