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 pinselectable

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 currentsensing

applications. The device can measure fullscale

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.