INA791x –4V to 110V, Bidirectional, Ultra-Precise, High Bandwidth Current Sense

Amplifier With 75A EZShunt™ Technology

1 Features

• Precision design with integrated shunt resistor

– ±75A continuous current at 25°C

– ±50A continuous current at +125°C

– Shunt resistor: 400µΩ

– Shunt inductance: 2nH

• Wide common-mode voltage range: –4V to +110V

• High small signal bandwidth : 1MHz

• Excellent CMRR

– 160dB DC CMRR

– 114dB AC CMRR at 50kHz

• High measurement accuracy

– System Gain error (maximum)

• Version A: ±0.35%, ±35ppm/°C drift

• Version B: ±1%, ±100ppm/°C drift

– Offset current (maximum)

• Version A: ±40mA, ±70mA over temperature

• Version B: ±210mA, ±250mA over

temperature

• Adjustable gain with external resistor divider

network: 20mV/A to 400mV/A

• Open-drain temperature alert at TJ of 160°C

2 Applications

• 48V DC/DC Converter

• 48V battery management systems (BMS)

• Test & Measurement

• Macro remote radio unit (RRU)

• 48V rack server

• 48V merchant network & server power supply

(PSU)

3 Description

The INA791x is a voltage output, current sense

amplifier with an integrated shunt resistor of 400μΩ.

The INA791x is designed to monitor bidirectional

current over a common-mode range of –4V to 110V,

independent of the supply voltage. Adjustable gain

option assists in optimizing the system dynamic

range. The integration of the Kelvin connected shunt

resistor with a zero-drift chopped amplifier provides

calibration equivalent measurement accuracy, ultra-

low temperature drift performance of ±35ppm/°C, and

an optimized layout for the sensing resistor.

This device operates from a single 2.7V to 5.5V power

supply, drawing a maximum of 4.25mA of supply

current. All versions are specified over the extended

operating temperature range (–40°C to +125°C), and

are available in a 15-pin VQFN package.

Package Information

PART NUMBER

PACKAGE(1)

PACKAGE SIZE(2)

INA791A, INA791B

DEK (VQFN, 15)

6mm × 6mm

(1)

For all available packages, see the orderable addendum at

the end of the data sheet.

(2)

The package size (length × width) is a nominal value and

includes pins, where applicable.

+

–

Shunt

Resistor

OUT

FB

REF

VS

GND

IS+

IS-

IN-

IN+

2.7V to 5.5V

+

–

EXT REF

Shunt Current

Alert

Bus Common Mode Voltage:

-4V to 110V

LOAD

up to 50A

GND

Rpullup

RFB1

RFB2

0.1 F

Typical Application

Ambient Temperature (°C)

-20

0

20

40

60

80

100

120

140

160

180

0

10

20

30

40

50

60

70

80

90

100

110

Maximum Continuous Current vs Ambient

Temperature

INA791A, INA791B

SBOSAD1A – MAY 2024 – REVISED JULY 2025

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.