Overvoltage

Protection

IN

Input Transistor

+V

-V

+

±

Input Voltage

Source

ZD1

ZD2

-5

-4

-3

-2

-1

0

1

2

3

4

5

±6

±4

±2

0

2

4

6

Output Voltage (V)

G = 1

G = 100

C006

-20

-15

-10

-5

0

5

10

15

±20

±10

0

10

20

Output Voltage (V)

G = 1

G = 100

C006

24

INA821

SBOS893A – AUGUST 2018 – REVISED DECEMBER 2018

www.ti.com

Product Folder Links: INA821

Submit Documentation Feedback

Copyright © 2018, Texas Instruments Incorporated

Figure 60. Input Common-Mode Voltage vs Output Voltage

Figure 61. Input Common-Mode Voltage vs Output Voltage

8.3.4 Input Protection

The inputs of the INA821 device are individually protected for voltages up to ±40 V. For example, a condition of

–40 V on one input and 40 V on the other input does not cause damage. Internal circuitry on each input provides

low series impedance under normal signal conditions. If the input is overloaded, the protection circuitry limits the

input current to a value of approximately 8 mA.

Figure 62. Input Current Path During an Overvoltage Condition