INA229 85-V, 20-Bit, Ultra-Precise Power/Energy/Charge Monitor With SPI Interface

1 Features

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

• Current monitoring accuracy:

– Offset voltage: ±1 µV (maximum)

– Offset drift: ±0.01 µV/°C (maximum)

– Gain error: ±0.05% (maximum)

– Gain error drift: ±20 ppm/°C (maximum)

– Common mode rejection: 154 dB (minimum)

• Power monitoring accuracy:

– 0.5 % full scale, –40 °C to 125 °C (maximum)

• Energy and Charge accuracy:

– 1.0 % full scale (maximum)

• Fast Alert response: 75 μs

• Wide common-mode range: –0.3 V to +85 V

• Bus voltage sense input: 0 V to 85 V

• Shunt full-scale differential range:

±163.84 mV / ± 40.96 mV

• Input bias current: 2.5 nA (maximum)

• Temperature sensor: ±1 °C (maximum at 25 °C)

• Programmable resistor temperature compensation

• Programmable conversion time and averaging

• 10-MHz SPI communication interface

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

– Operational current: 640 µA (typical)

– Shutdown current: 5 µA (maximum)

2 Applications

• DC-DC converters and power inverters

• Industrial battery packs

• Power-over-Ethernet (PoE)

• Telecom equipment

• Enterprise servers

3 Description

The INA229 is an ultra-precise digital power monitor

with a 20-bit delta-sigma ADC specifically designed

for current-sensing applications. The device can

measure a full-scale differential input of ±163.84 mV

or ±40.96 mV across a resistive shunt sense element

with common-mode voltage support from –0.3 V to

+85 V.

The INA229 reports current, bus voltage, 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 ±1

°C accurate for die temperature measurement and is

useful in monitoring the system ambient temperature.

The low offset and gain drift design of the INA229

allows it to be used in precise systems that do not

undergo

multi-temperature

calibration

during

manufacturing. Further, the very low offset voltage

and noise allow for use in mA to kA sensing

applications and provide a wide dynamic range

without significant power dissipation losses on the

sensing shunt element. The low input bias current of

the device permits the use of larger current-sense

resistors,

thus

providing

accurate

current

measurements in the micro-amp range.

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.

Device Information (1)

PART NUMBER

PACKAGE

BODY SIZE (NOM)

INA229

VSSOP (10)

3.00 mm × 3.00 mm

(1)

For all available packages, see the package option

addendum at the end of the data sheet.

Oscillator

Voltage

Current

Power

Energy

Charge

Temp

+

±

SCLK

MOSI

MISO

CS

VS

Power

GND

ALERT

IN+

IN-

VBUS

SPI

20 Bit

ADC

Reference

Out-of-range

Threshold

MUX

Simplified Block Diagram

www.ti.com

INA229

SLYS023 – DECEMBER 2020

Copyright © 2020 Texas Instruments Incorporated

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INA229

SLYS023 – DECEMBER 2020

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.