INA3221 datasheet(37/50 Pages) TI2

37 / 50 page

8 Application and Implementation

Note

Information in the following applications sections is not part of the TI component specification,

and TI does not warrant its accuracy or completeness. TI’s customers are responsible for

determining suitability of components for their purposes, as well as validating and testing their design

implementation to confirm system functionality.

8.1 Application Information

INA3221 is a three-channel current and bus voltage monitor with I2C/SMBUS-compatible interface. It features

programmable conversion times and averaging modes and offers both critical and warning alerts to detect

multiple programmable out-of-range conditions for each channel.

8.2 Typical Application

The INA3221 measures the voltage developed across a current-sensing resistor when current passes through

the resistor. The device also measures the bus supply voltage at the IN- pin. Multiple monitoring functions are

supported using four alert pins: Critical, Warning, PV, and TC. Programmable thresholds make sure operation is

within desired operating conditions. This design illustrates the ability of the Critical alert pin to respond to a set

threshold.

Figure 8-1 illustrates a typical INA3221 application circuit using all three channels. For best performance, use a

0.1μF ceramic capacitor for power-supply bypassing, placed as close as possible to the supply and ground pins.

The digital pins (SCL, SDA, Critical, Warning, TC) are connected to supply through pull-up resistors. The power

valid (PV) alert pin is connected to the VPU pin through a pull-up resistor to enable power-valid monitoring.

Power Supply

(0V to 26V)

Load 1

Load 2

Power Supply

(0V to 26V)

Load 3

Power Supply

(0V to 26V)

CBYPASS

0.1µF

VS (Supply

Voltage)

CH 1

CH 2

VIN–1

VIN+1

VIN–2

VIN+2

CH 3

VIN–3

VIN+3

2C-

and

SMBus-

Compatible

Interface

SDA

SCL

Critical

Warning

GND

ADC

Shunt

Voltages 1-3

Critical Limit

Alerts 1-3

Bus

Voltages 1-3

Power Valid (PV)

Timing Control (TC)

Shunt Voltage

Sum Alerts

VPU

10kΩ

VPU

10kΩ

Figure 8-1. INA3221 as an Overcurrent Sensor

www.ti.com

INA3221

SBOS576C – MAY 2012 – REVISED SEPTEMBER 2025

Submit Document Feedback

Product Folder Links: INA3221

INA3221 Datasheet(PDF) 37 Page - Texas Instruments

INA3221 Datasheet(HTML) 37 Page - Texas Instruments

Html Pages

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50

Datasheet Download

Link URL