IN+

IN±

OUT

V

CM

-

+

Buffer

Current

Feedback

V

S

GND

RL

R1

R1

Bias

Load

R

SENSE

I

SENSE

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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. PRODUCTION DATA.

INA281

SBOSA29 – JUNE 2020

INA281, –4-V to 110-V, 1.3-MHz Current-Sense Amplifier

1

1 Features

1

•

Wide common-mode voltage:

–

Operational voltage:

−4 V to +110 V

–

Survival voltage:

−20 V to +120 V

•

Excellent CMRR:

–

120-dB DC CMRR

–

65-dB AC CMRR at 50 kHz

•

Accuracy:

–

Gain:

–

Gain error: ±0.5% (maximum)

–

Gain drift: ±20 ppm/°C (maximum)

–

Offset:

–

Offset voltage: ±55 µV (typical)

–

Offset drift: ±0.1 µV/°C (typical)

•

Available gains:

–

INA281A1, INA281B1 : 20 V/V

–

INA281A2, INA281B2 : 50 V/V

–

INA281A3, INA281B3 : 100 V/V

–

INA281A4, INA281B4 : 200 V/V

–

INA281A5, INA281B5 : 500 V/V

•

High bandwidth: 1.3 MHz

•

Slew rate: 2.5V/µs

•

Quiescent current: 1.5 mA

2 Applications

•

Active antenna system mMIMO (AAS)

•

Macro remote radio unit (RRU)

•

48-V rack server

•

48-V merchant network & server power supply

(PSU)

•

Solenoid control

•

Valve control

•

Telecom equipment

•

Power supplies

3 Description

The

INA281

is

a

high-precision

current

sense

amplifier that can measure voltage drops across

shunt resistors over a wide common-mode range

from –4 V to 110 V. The negative common-mode

voltage allows the device to operate below ground,

thus

accommodating

precise

measurement

of

recirculating currents in half-bridge applications. The

combination of a low offset voltage, small gain error

and high DC CMRR enables highly accurate current

measurement. The INA281 is not only designed for

DC current measurement, but also for high-speed

applications (like fast overcurrent protection, for

example) with a high bandwidth of 1.3 MHz and an

65-dB AC CMRR (at 50 kHz).

The INA281 operates from a single 2.7-V to 20-V

supply, drawing 1.5 mA of supply current. The

INA281 is available with five gain options: 20 V/V, 50

V/V, 100 V/V, 200 V/V, and 500 V/V. These gain

options address wide dynamic range for current-

sensing applications.

The

INA281

is

specified

over

an

operating

temperature range of

−40 °C to +125 °C and is

offered in a space-saving SOT-23 package with two

pin-out variants.

Device Information(1)

PART NUMBER

PACKAGE

BODY SIZE (NOM)

INA281

SOT-23 (5)

2.90 mm × 1.60 mm

(1) For all available packages, see the package option addendum

at the end of the data sheet.

Functional Block Diagram