A

1

A

2

A

3

6

150kW

150kW

150kW

150kW

7

4

3

8

1

2

V

IN-

V

IN+

R

G

V+

V-

INA333

G=1+

100kW

R

G

5

RFIFilter

50kW

50kW

RFIFilter

Load

V =G

(V

´

V

-

)

O

IN+

IN-

0.1 F

m

0.1 F

m

+

-

V

O

R

G

Alsodrawninsimplifiedform:

INA333

Ref

V

O

V

IN-

V

IN+

Ref

RFIFilter

RFIFilter

14

INA333

SBOS445C – JULY 2008 – REVISED DECEMBER 2015

www.ti.com

Product Folder Links: INA333

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Copyright © 2008–2015, Texas Instruments Incorporated

8 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.

8.1 Application Information

The INA333 measures small differential voltage with high common-mode voltage developed between the

noninverting and inverting input. The high input impedance makes the INA333 suitable for a wide range of

applications. The ability to set the reference pin to adjust the functionality of the output signal offers additional

flexibility that is practical for multiple configurations.

8.2 Typical Application

Figure 32 shows the basic connections required for operation of the INA333 device. Good layout practice

mandates the use of bypass capacitors placed close to the device pins as shown.

The output of the INA333 device is referred to the output reference (REF) pin, which is normally grounded. This

connection must be low-impedance to assure good common-mode rejection. Although 15

Ω or less of stray

resistance can be tolerated while maintaining specified CMRR, small stray resistances of tens of

Ωs in series

with the REF pin can cause noticeable degradation in CMRR.

Figure 32. Basic Connections