INA781 85 V, 20-Bit, Ultra-Precise I2C Output Digital Power Monitor with EZShunt™

Technology

1 Features

• Low loss integrated shunt resistor

– Internal resistance: 400 µΩ, TA = 25°C

– Continuous current: ±75 A, TA = 25°C

– Peak measurement capability: ±78.64 A

• Wide common-mode range: –0.1 V to +85 V

• High-resolution, 20-bit delta-sigma ADC

• Current monitoring accuracy:

– Offset current: ±5.5 mA, maximum

– Offset drift: ±25 µA/°C, maximum

– System gain error: ±0.5% at 50 A

– System gain error drift: ±25 PPM/°C, typical

– Common-mode rejection: ±100 µA/V, maximum

• Power monitoring accuracy:

– ±0.6% at 25°C, full scale

• Energy and charge accuracy:

– ±1.1% at 25°C, full scale

• Input bias current: 2.5 nA (maximum)

• Temperature sensor: ±1.5°C (maximum at 25°C)

• Programmable conversion time and averaging

• 2.94-MHz high-speed I2C interface with 16 pin-

selectable addresses

• Operates from a 2.7-V to 5.5-V supply:

– Operational current: 640 µA (typical)

– Shutdown current: 5 µA (maximum)

2 Applications

• Power delivery

• Grid infrastructure

• Industrial battery packs

• Test equipment

• Telecom equipment

• Enterprise servers

3 Description

The INA781 is a digital power monitor with an

integrated current sensing element along with a 20-

bit delta-sigma ADC specifically designed for current-

sensing applications. The device can measure full-

scale currents up to ±78.64 A with common-mode

voltage support from –0.1 V to +85 V.

The INA781 reports current, bus voltage, die

temperature, power, energy and charge accumulation

while employing a precision ±0.5% integrated

oscillator, all while performing the needed calculations

in the background. The integrated temperature sensor

is ±2.5°C accurate over the junction temperature

range.

The low offset and gain drift design of the INA781

allows the device to be used in precise systems that

do not undergo multi-temperature calibration during

manufacturing.

The device allows for selectable ADC conversion

times from 50 µs to 4.12 ms as well as sample

averaging from 1x to 1024x, which further helps

reduce the noise of the measured data.

Package Information

PART NUMBER

PACKAGE(1)

PACKAGE

SIZE (NOM)(2)

INA781

DEK (WSON, 15)

6.00 mm × 6.00 mm

(1)

For all available packages, see the package option

addendum at the end of the data sheet.

(2)

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

includes pins, where applicable.

GND

20 – bit

ADC

V

I

Common-mode Voltage

(-0.1 V to 85 V)

TI Device

IS+

IS-

±0.5% Oscillator

VBUS

IN+

IN-

SH+

SH-

Power

Current

Bus Voltage

Temperature

Energy

Charge

Alert_Diag

Shunt TC

Compensation

Registers

V

I

I

2C / SMBus

Interface

A0

A1

ALERT

SDA

SCL

0.1 µF

VS

Supply Voltage

(2.7 V to 5.5 V)

Simplified Block Diagram

INA781

SBOSAC0 – JULY 2023

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. ADVANCE INFORMATION for preproduction products; subject to change

without notice.