INA138

INA168

FEATURES

q COMPLETE UNIPOLAR HIGH-SIDE

CURRENT MEASUREMENT CIRCUIT

q WIDE SUPPLY AND COMMON-MODE RANGE

q INA138: 2.7V to 36V

q INA168: 2.7V to 60V

q INDEPENDENT SUPPLY AND INPUT COMMON-

MODE VOLTAGES

q SINGLE RESISTOR GAIN SET

q LOW QUIESCENT CURRENT (25

q WIDE TEMPERATURE RANGE: –40

q SOT23-5 PACKAGE

High-Side Measurement

CURRENT SHUNT MONITOR

DESCRIPTION

The INA138 and INA168 are high-side, unipolar, current

shunt monitors. Wide input common-mode voltage range,

low quiescent current, and tiny SOT23 packaging enable use

in a variety of applications.

Input common-mode and power-supply voltages are inde-

pendent and can range from 2.7V to 36V for the INA138 and

2.7V to 60V for the INA168. Quiescent current is only 25

µA,

which permits connecting the power supply to either side of

the current measurement shunt with minimal error.

The device converts a differential input voltage to a current

output. This current is converted back to a voltage with an

external load resistor that sets any gain from 1 to over 100.

Although designed for current shunt measurement, the circuit

invites creative applications in measurement and level shifting.

Both the INA138 and INA168 are available in SOT23-5 and

are specified for the –40

°C to +125°C temperature range.

APPLICATIONS

q CURRENT SHUNT MEASUREMENT:

Automotive, Telephone, Computers

q PORTABLE AND BATTERY-BACKUP

SYSTEMS

q BATTERY CHARGERS

q POWER MANAGEMENT

q CELL PHONES

q PRECISION CURRENT SOURCE

R

S

2

1

OUT

GND

R

L

V

Load

5k

Ω

5k

Ω

V

IN+

Up To 60V

V

IN+

V

IN–

3

4

I

S

V+

5

www.ti.com

PRODUCTION DATA information is current as of publication date.

Products conform to specifications per the terms of Texas Instruments

standard warranty. Production processing does not necessarily include

testing of all parameters.

Copyright © 1999-2005 Texas Instruments Incorporated

Please be aware that an important notice concerning availability, standard warranty, and use in critical applications of

Texas Instruments semiconductor products and disclaimers thereto appears at the end of this data sheet.

SBOS122C – DECEMBER 1999 – REVISED NOVEMBER 2005

All trademarks are the property of their respective owners.