1 Features

• Low power:

– Supply voltage, VS: 1.7 V to 5.5 V

– Shutdown current: 100 nA (max INA191)

– Quiescent current: 43 μA at 25 °C (INA191)

• 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:

– INA191: 0.895-mm2 DSBGA

– INA2191: 1.79-mm2 DSBGA

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 commonmode

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 currentsense

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 INA191 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.