INAx191 40-V, Bidirectional, Ultra-Precise Current Sense Amplifier With picoamp IB

and ENABLE in WCSP Package

1 Features

• Low power:

– Low shutdown current: 100 nA (maximum)

– Low quiescent current: 43 μA at 25 °C (typical)

• Low input bias currents: 100 pA (typical)

(enables microamp current measurement)

• Bidirectional current measurement (INA2191)

• Accuracy:

– ±0.25% max gain error (A2 to A5 devices)

– 7-ppm/°C gain drift (maximum)

– ±12 μV (maximum) offset voltage

– 0.13-μV/°C offset drift (maximum)

• Wide common-mode voltage: –0.2 V to +40 V

• Gain options:

– INAx191A1: 25 V/V

– INAx191A2: 50 V/V

– INAx191A3: 100 V/V

– INAx191A4: 200 V/V

– INAx191A5: 500 V/V

• Packages:

2 Applications

• Notebook computers

• Cell phones

• Battery-powered devices

• Telecom equipment

• Power management

• Battery chargers

3 Description

The INAx191 is a low-power, voltage-output, current-

shunt monitor (also called a current-sense amplifier)

that is commonly used for overcurrent protection,

precision-current

measurement

for

system

optimization, or in closed-loop feedback circuits. This

device can sense drops across shunts at common-

mode voltages from –0.2 V to +40 V, independent of

the supply voltage. The low input bias current of the

INAx191 permits the use of larger current-sense

resistors,

and

thus

provides

accurate

current

measurements in the µA range. Five fixed gains are

available: 25 V/V, 50 V/V, 100 V/V, 200 V/V, or 500

V/V. The low offset voltage of the zero-drift

architecture extends the dynamic range of the current

measurement, and allows for smaller sense resistors

with lower power loss while still providing accurate

current measurements.

The INAx191 operates from a single 1.7-V to 5.5-V

power supply, drawing a maximum of 65 µA of supply

current when enabled and only 100 nA when

disabled. The device is specified over the operating

temperature range of –40 °C to +125 °C, and offered

in a DSBGA-6 (INA191) and DSBGA-12 (INA2191)

packages.

Device Information (1)

PART NUMBER

PACKAGE

BODY SIZE (NOM)

INA191

DSBGA (6)

1.17 mm × 0.765 mm

INA2191(2)

DSBGA (12)

1.17 mm × 1.53 mm

(1)

For all available packages, see the package option

addendum at the end of the data sheet.

(2)

Advanced Information only.

ADC

ENABLE

VS

OUT

GND

IN+

IN±

LOAD

Microcontroller

Supply Voltage

1.7 V to 5.5 V

100 pA

(typical)

100 pA

(typical)

0.1 …F

INA191

INA2191 (½)

Bus Voltage

up to 40 V

REF

(1)

(1) REF pin only available on INA2191

Simplified Schematic

www.ti.com

INA191, INA2191

SLYS020B – FEBRUARY 2019 – REVISED FEBRUARY 2021

Copyright © 2021 Texas Instruments Incorporated

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INA191, INA2191

SLYS020B – FEBRUARY 2019 – REVISED FEBRUARY 2021

An IMPORTANT NOTICE at the end of this data sheet addresses availability, warranty, changes, use in safety-critical applications,

intellectual property matters and other important disclaimers. UNLESS OTHERWISE NOTED, this document contains PRODUCTION

DATA.