Texas Instruments INA226EVM User manual

User’s Guide
INA226EVM Rev A Model
User's Guide and Software Tutorial
Patrick Simmons, Dennis Goeke, and Scott Hill High-Performance Linear Product
ABSTRACT
This user's guide describes the characteristics, operation, and use of the INA226EVM revision A evaluation
board. It discusses how to set up and configure the software and hardware, and reviews various aspects of
the program operation. Throughout this document, the terms evaluation board, evaluation module, and EVM are
synonymous with the INA226EVM. This user's guide also includes information regarding operating procedures
and input/output connections, an electrical schematic, printed circuit board (PCB) layout drawings, and a parts
list for the EVM.
Table of Contents
1 Trademarks..............................................................................................................................................................................2
2 Overview..................................................................................................................................................................................2
2.1 INA226EVM Kit Contents...................................................................................................................................................3
2.2 Related Documentation from Texas Instruments............................................................................................................... 4
3 INA226EVM Hardware Setup................................................................................................................................................. 4
3.1 Theory of Operation for INA226 Hardware........................................................................................................................ 5
3.2 Signal Definitions of H1 (10-Pin Connector Socket).......................................................................................................... 5
4 INA226EVM Hardware............................................................................................................................................................ 6
4.1 Electrostatic Discharge Warning........................................................................................................................................ 6
4.2 Connecting the Hardware.................................................................................................................................................. 7
4.3 Connecting Power..............................................................................................................................................................7
4.4 Connecting the USB Cable to the SM-USB-DIG Platform................................................................................................. 8
4.5 INA226EVM Default Jumper Settings................................................................................................................................ 9
4.6 INA226EVM Features...................................................................................................................................................... 10
5 INA226EVM Software Setup.................................................................................................................................................12
5.1 Hardware Requirements.................................................................................................................................................. 12
5.2 Software Installation.........................................................................................................................................................12
6 INA226EVM Software Overview...........................................................................................................................................14
6.1 Starting the INA226EVM Software...................................................................................................................................14
6.2 Configuring the INA226EVM Software.............................................................................................................................15
6.3 Using the INA226EVM Software...................................................................................................................................... 18
7 INA226EVM Documentation.................................................................................................................................................22
7.1 Schematic........................................................................................................................................................................ 23
7.2 PCB Layout...................................................................................................................................................................... 24
7.3 Bill of Materials.................................................................................................................................................................25
8 Revision History................................................................................................................................................................... 26
List of Figures
Figure 2-1. Hardware Included With INA226EVM Kit.................................................................................................................. 3
Figure 3-1. INA226EVM Hardware Setup....................................................................................................................................4
Figure 3-2. INA226EVM Board Block Diagram............................................................................................................................5
Figure 3-3. SM-USB-DIG Platform Block Diagram...................................................................................................................... 6
Figure 4-1. Typical Hardware Test Connections for INA226EVM................................................................................................ 7
Figure 4-2. Connecting the USB Cable to the SM-USB-DIG Platform........................................................................................ 8
Figure 4-3. Confirmation of SM-USB-DIG Platform Driver Installation........................................................................................ 8
Figure 4-4. INA226EVM Default Jumper Settings....................................................................................................................... 9
Figure 4-5. Typical Filter Setup.................................................................................................................................................. 11
www.ti.com Table of Contents
SBOU113A – JUNE 2011 – REVISED JANUARY 2023
Submit Document Feedback
INA226EVM Rev A Model
User's Guide and Software Tutorial
1
Copyright © 2023 Texas Instruments Incorporated

Figure 4-6. INA226 Shunt Configurations..................................................................................................................................12
Figure 5-1. INA226EVM Software Installation........................................................................................................................... 13
Figure 5-2. INA226EVM License Agreements...........................................................................................................................13
Figure 5-3. INA226EVM Software Installation Progress............................................................................................................13
Figure 6-1. INA226EVM Software Interface.............................................................................................................................. 14
Figure 6-2. INA226EVM Software: Communication Error With the SM-USB-DIG Platform...................................................... 15
Figure 6-3. Setting the I2C Address...........................................................................................................................................16
Figure 6-4. Configuring Operating Mode................................................................................................................................... 16
Figure 6-5. Configuring Conversion Times................................................................................................................................ 17
Figure 6-6. Setting the Configuration Register (Calibration Register)....................................................................................... 18
Figure 6-7. Setting the Configuration Register (Current LSB)................................................................................................... 18
Figure 6-8. Configuring the Alert Pin......................................................................................................................................... 18
Figure 6-9. INA226 Results Bar.................................................................................................................................................19
Figure 6-10. Theory of Operation Flowchart on the Calculation Tab......................................................................................... 19
Figure 6-11. Registers Tab.........................................................................................................................................................20
Figure 6-12. Graphing the INA226 Data.................................................................................................................................... 21
Figure 6-13. Auto-Write, Power Button, and Voltage Control.................................................................................................... 22
Figure 7-1. INA226EVM Schematic...........................................................................................................................................23
Figure 7-2. INA226EVM PCB Top Layer (Component Side)..................................................................................................... 24
List of Tables
Table 2-1. INA226EVM Kit Contents............................................................................................................................................3
Table 2-2. Related Documentation.............................................................................................................................................. 4
Table 3-1. Signal Definition of J1 on INA226EVM Board.............................................................................................................5
Table 4-1. INA226EVM Test Board Jumper Functions.............................................................................................................. 10
Table 6-1. INA226 I2C Address Configuration........................................................................................................................... 15
Table 7-1. Bill of Materials: INA226EVM....................................................................................................................................25
1 Trademarks
Microsoft® and Windows® are registered trademarks of Microsoft Corporation.
WinZIP® is a registered trademark of WinZip International LLC.
All trademarks are the property of their respective owners.
2 Overview
The INA226 is a high- or low-side current sensor and power monitor with an I2C interface. The INA226 monitors
both current and supply voltage, with programmable conversion times and averaging modes. The INA226EVM is
a platform for evaluating the performance of the INA226 under various signal, shunt, and supply conditions.
This document gives a general overview of the INA226EVM, and provides a general description of the features
and functions to consider while using this evaluation module.
Trademarks www.ti.com
2INA226EVM Rev A Model
User's Guide and Software Tutorial
SBOU113A – JUNE 2011 – REVISED JANUARY 2023
Submit Document Feedback
Copyright © 2023 Texas Instruments Incorporated

2.1 INA226EVM Kit Contents
Table 2-1 summarizes the contents of the INA226EVM kit. Figure 2-1 shows all of the included hardware.
Contact the Texas Instruments customer support center if any component is missing. TI highly recommends that
you also check the INA226 product folder on the TI web site at www.ti.com to verify that you have the latest
versions of the related software.
Table 2-1. INA226EVM Kit Contents
ITEM QUANTITY
INA226EVM PCB Test Board 1
SM-USB-DIG Platform PCB 1
USB Extender Cable 1
SM-Dig Connector Ribbon Cable 1
User’s Guide CD-ROM 1
Figure 2-1. Hardware Included With INA226EVM Kit
www.ti.com Overview
SBOU113A – JUNE 2011 – REVISED JANUARY 2023
Submit Document Feedback
INA226EVM Rev A Model
User's Guide and Software Tutorial
3
Copyright © 2023 Texas Instruments Incorporated

2.2 Related Documentation from Texas Instruments
The following documents provide information regarding Texas Instruments' integrated circuits used in the
assembly of the INA226EVM. This user's guide is available from the TI web site under literature number
SBOU113. Any letter appended to the literature number corresponds to the document revision that is current at
the time of the writing of this document. Newer revisions may be available from the TI web site, or call the Texas
Instruments' Literature Response Center at [phone] or the Product Information Center at [phone].
When ordering, identify the document by both title and literature number.
Table 2-2. Related Documentation
DOCUMENT LITERATURE NUMBER
INA226 Product Data Sheet SBOS547
SM-USB-DIG Platform User
Guide SBOU098
3 INA226EVM Hardware Setup
Figure 3-1 shows the overall system setup for the INA226EVM. The PC runs software that communicates
with the SM-USB-DIG Platform. The SM-USB-DIG Platform generates the analog and digital signals used to
communicate with the INA226 test board. Connectors on the INA226EVM test board allow the user to connect to
the system under test conditions and monitor the power, current, and voltage.
Desktop or Lab Computer/
Laptop SM-USB-DIG Platform INA226EVM
Shunt
Load
Power
Supply
Figure 3-1. INA226EVM Hardware Setup
Overview www.ti.com
4INA226EVM Rev A Model
User's Guide and Software Tutorial
SBOU113A – JUNE 2011 – REVISED JANUARY 2023
Submit Document Feedback
Copyright © 2023 Texas Instruments Incorporated

3.1 Theory of Operation for INA226 Hardware
Figure 3-2 shows a block diagram of the INA226 test board hardware setup. The PCB provides connections
to the I2C interface and general-purpose inputs/outputs (GPIOs) on the SM-USB-DIG Platform board. It also
provides connection points for external connections of the shunt voltage, bus voltage, and ground.
INA226
V Supply
(DVDD)
DUT
I C Interface
2
10-Pin Female
SM-USB-DIG
Connector
J5/J6
J3/J4
J1
Shunt Terminals
T3/T4
4
I C Address
Jumpers
2
A0
A1
Figure 3-2. INA226EVM Board Block Diagram
3.2 Signal Definitions of H1 (10-Pin Connector Socket)
Table 3-1 lists the pinout for the 10-pin connector socket used to communicate between the INA226EVM and the
SM-USB-DIG. It should be noted that the INA226EVM only uses the necessary I2C communication lines (pins 1
and 3) and the VDUT and GND pins (pin 6 and pin 8) to issue commands to the INA226 chip.
Table 3-1. Signal Definition of J1 on INA226EVM Board
PIN ON J1 SIGNAL DESCRIPTION
1 I2C_SCL I2C Clock Signal (SCL)
2 CTRL/MEAS4 GPIO: Control Output or Measure
Input
3 I2C_SDA1 I2C Data Signal (SDA)
4 CTRL/MEAS5 GPIO: Control Output or Measure
Input
5 SPI_DOUT1 SPI Data Output (MOSI)
6 VDUT
Switchable DUT Power Supply: +3.3
V, +5 V, Hi-Z (Disconnected)(1)
7 SPI_CLK SPI Clock Signal (SCLK)
8 GND Power Return (GND)
9 SPI_CS1 SPI Chip Select Signal ( CS)
10 SPI_DIN1 SPI Data Input (MISO)
(1) When VDUT is Hi-Z, all digital I/O are Hi-Z as well.
www.ti.com INA226EVM Hardware Setup
SBOU113A – JUNE 2011 – REVISED JANUARY 2023
Submit Document Feedback
INA226EVM Rev A Model
User's Guide and Software Tutorial
5
Copyright © 2023 Texas Instruments Incorporated

3.2.1 Theory of Operation for SM-USB-DIG Platform
Figure 3-3 shows the block diagram for the SM-USB-DIG Platform. This platform is a general-purpose data
acquisition system that is used on several different Texas Instruments evaluation modules. The details of its
operation are included in a separate document, SBOU098 (available for download at www.ti.com). The block
diagram shown in Figure 3-3 gives a brief overview of the platform. The primary control device on the SM-USB-
DIG Platform is the TUSB3210. The TUSB3210 is an 8052 microcontroller that has an onboard USB interface.
The microcontroller receives information from the host computer that it interprets into power, I2C, SPI, and other
digital I/O patterns. During the digital I/O transaction, the microcontroller reads the response of any device
connected to the I/O interface. The response from the device is sent back to the PC where it is interpreted by the
host computer.
TUSB3210
8052 Cm
with USB Interface
and UART
8Kx8-byte
EEPROM
+3.3V
VUSB
+5V
Power-On Reset SM USB DIG Platform
To Test Board
To Computer and Power Supplies
Power
Switching
Switched
Power
USB Bus
from
Computer
USB Power
+5.0V
+3.0V
V
(H-Z, 3.3V, or 5V)
DUT
Buffers and
Level Translators
I C/SPI
Control and
Measure Bits
2
+3.3V
Regulator
Figure 3-3. SM-USB-DIG Platform Block Diagram
4 INA226EVM Hardware
Setting up the INA226EVM hardware involves connecting the two PCBs of the EVM together, applying power,
connecting the USB cable, and setting the jumpers. This section presents the details of this procedure.
4.1 Electrostatic Discharge Warning
CAUTION
Many of the components on the INA226EVM are susceptible to damage by electrostatic discharge
(ESD). Customers are advised to observe proper ESD handling precautions when unpacking and
handling the EVM, including the use of a grounded wrist strap at an approved ESD workstation.
INA226EVM Hardware Setup www.ti.com
6INA226EVM Rev A Model
User's Guide and Software Tutorial
SBOU113A – JUNE 2011 – REVISED JANUARY 2023
Submit Document Feedback
Copyright © 2023 Texas Instruments Incorporated

4.2 Connecting the Hardware
To set up the INA226EVM and connect the two PCBs of the EVM together (that is, the INA226 Test Board
and SM-USB-DIG Platform board), gently slide the plug and socket ends of the 10-pin connectors together.
Make sure that the two connectors are completely pushed together; loose connections may cause intermittent
operation.
4.3 Connecting Power
After the EVM and SM-USB-DIG are conjoined, as Figure 4-1 illustrates, connect the desired VBUS and shunt
configuration intended to be measured. Typically, setup involves a high- or low-side load and a shunt resistor
across VIN+ and VIN–. The setup in Figure 4-1 represents a test scenario with a low-side shunt attached. This
source for VBUS is not included with the kit, and its voltage may differ depending on your testing needs. The
external power source is connected to the terminal strip T3.
Note
It is always necessary to connect the power to the SM-USB-DIG Platform board before connecting the
USB cable.
Figure 4-1. Typical Hardware Test Connections for INA226EVM
www.ti.com INA226EVM Hardware
SBOU113A – JUNE 2011 – REVISED JANUARY 2023
Submit Document Feedback
INA226EVM Rev A Model
User's Guide and Software Tutorial
7
Copyright © 2023 Texas Instruments Incorporated

4.4 Connecting the USB Cable to the SM-USB-DIG Platform
When the power is connected, as shown in Figure 4-2, the computer typically responds with a Found New
Hardware, USB Device pop-up dialog. The pop-up window typically changes to Found New Hardware, USB
Human Interface Device. This pop-up indicates that the device is ready to be used. The SM-USB-DIG Platform
uses the human interface device drivers that are part of the Microsoft® Windows® operating system.
Figure 4-2. Connecting the USB Cable to the SM-USB-DIG Platform
In some cases, the Windows Add Hardware Wizard may pop up. If this prompt appears, click Yes to allow the
system device manager to install the human interface drivers. Figure 4-3 shows the confirmation message when
the drivers are installed.
Figure 4-3. Confirmation of SM-USB-DIG Platform Driver Installation
INA226EVM Hardware www.ti.com
8INA226EVM Rev A Model
User's Guide and Software Tutorial
SBOU113A – JUNE 2011 – REVISED JANUARY 2023
Submit Document Feedback
Copyright © 2023 Texas Instruments Incorporated

4.5 INA226EVM Default Jumper Settings
Figure 4-4 shows the default jumper configuration for the INA226EVM. In general, the jumper settings of the
SM-USB-DIG Platform do not need to be changed. You may want to change some of the jumpers on the
INA226EVM board to match your specific configuration. For example, you may wish to set a specific I2C address
by configuring J3-J6.
Figure 4-4. INA226EVM Default Jumper Settings
Typically, jumper 2 on the INA226EVM is always set to the INT position. When set to the INT position, the
SM-USB-DIG Platform provides the supply for the INA226. When this jumper is set to the EXT position, an
external supply voltage can be connected to terminal strip T2 to provide the supply for the INA226.
Jumpers 3 through 6 control the I2C address pins for the INA226. These jumpers can set the address for A0 and
A1 to either supply, ground, SCL, or SDA. Make sure to only connect one jumper at a time for each address
control. Failure to properly connect jumpers can cause shorts or interruptions in the communication lines. For
more information on the INA226 addressing, refer to the INA226 product data sheet.
www.ti.com INA226EVM Hardware
SBOU113A – JUNE 2011 – REVISED JANUARY 2023
Submit Document Feedback
INA226EVM Rev A Model
User's Guide and Software Tutorial
9
Copyright © 2023 Texas Instruments Incorporated

Table 4-1 summarizes the function of the INA226 Test Board jumpers. For most applications, all jumpers should
be left in the respective default configurations.
Table 4-1. INA226EVM Test Board Jumper Functions
JUMPER DEFAULT PURPOSE
J2 INT
This jumper selects whether the VS pin
on the INA226 is connected to the VDUT
signal generated from the SM-USB-DIG
Platform or whether the digital supply pin
is connected to terminal T2, allowing for
an external supply to power the device.
The default INT position connects the VS
pin to the VDUT control signal.
J3/J4 GND This jumper selects the I2C A0 address
selection for A0.
J5/J6 GND This jumper selects the I2C A1 address
selection for A1.
4.6 INA226EVM Features
This section describes some of the hardware features present on the INA226EVM test board.
4.6.1 J2: I2C VS Control Setting
Jumper J2 selects what connects to the INA226 supply pin. If J2 is set to the INT position, the VS pin is
connected to the switchable VDUT signal generated from the SM-USB-DIG Platform. This voltage can be set to
either 3.3 V or 5 V, depending on how it is configured in the software. While J4 is set in the INT position, the VS
Power button in the INA226EVM software is able to control whether the VDUT supply voltage is turned on or off.
When J2 is set in the EXT position, an external supply connected to terminal T2 can be used to provide the
supply voltage for the INA226.
4.6.2 J3/J4: I2C Address Hardware Setting (A0)
Jumpers J3 and J4 are used to set the hardware setting for the A0 I2C address pin on the INA226. Using J3, the
A0 address can be set to either a logic '1' or a logic '0'. Using J4, the A0 address can be set to either the SCL
or SDA communication line. Make sure to only have either J3 or J4 connected individually; failure to keep these
lines separate can lead to board shorts and problems with the I2C communication lines. See Section 6.2.1 on
how to configure the INA226EVM software to match the J3/J4 hardware setting.
4.6.3 J5/J6: I2C Address Hardware Setting (A1)
Jumpers J5 and J6 are used to set the hardware setting for the A1 I2C address pin on the INA226. Using J3, the
A1 address can be set to either a logic '1' or a logic '0'. Using J4, the A1 address can be set to either the SCL
or SDA communication line. Make sure to only have either J5 or J6 connected individually; failure to keep these
lines separate can lead to board shorts and problems with the I2C communication lines. See Section 6.2.1 on
how to configure the INA226EVM software to match the J5/J6 hardware setting.
INA226EVM Hardware www.ti.com
10 INA226EVM Rev A Model
User's Guide and Software Tutorial
SBOU113A – JUNE 2011 – REVISED JANUARY 2023
Submit Document Feedback
Copyright © 2023 Texas Instruments Incorporated

4.6.4 External I2C Lines and Terminal Block T1
The I2C communication lines on the INA226EVM are tied to two sources: the internal I2C communication lines
from the SM-USB-DIG and the terminal block T1. If the user wants to add external signals separate from the
SM-USB-DIG, simply disconnect the SM-USB-DIG from the INA226EVM board and hook up the necessary SDA,
SCL, and GND lines. Also, remember to apply an external supply to the lines that is compatible with the I2C
communication device being used.
Note
Failure to disconnect the SM-USB-DIG while using external I2C communication can cause damage to
the SM-USB-DIG or any external communication devices that are connected.
4.6.5 VIN+/VIN– Input Filter (R1, R2, and C1)
The INA226EVM has an optional input filter to remove high-frequency noise from the inputs VIN+ and VIN–. This
filter is typically unpopulated. The default values for R1 and R2 are 0-Ω resistors. Figure 4-5 shows the typical
setup, which is recommended for basic INA226 evaluation.
Figure 4-5. Typical Filter Setup
www.ti.com INA226EVM Hardware
SBOU113A – JUNE 2011 – REVISED JANUARY 2023
Submit Document Feedback
INA226EVM Rev A Model
User's Guide and Software Tutorial
11
Copyright © 2023 Texas Instruments Incorporated

4.6.6 Shunt Monitor Configuration and Terminal Blocks T3 and T4
The INA226 is generally used in either a high-side or low-side shunt configuration, as shown in Figure 4-6.
Terminal block T3 represents VBUS and ground, while terminal block T4 represents VIN+ and VIN–. Depending
on the user’s needs, either of these configurations may be used without making any changes to the INA226EVM
board or software.
GND
VBUS
V
I
High-Side
Shunt
Low-Side
Shunt
Load
Power Supply
(0V to 36V)
VIN+
VIN-
Figure 4-6. INA226 Shunt Configurations
5 INA226EVM Software Setup
This section discusses how to install the INA226EVM software.
5.1 Hardware Requirements
The INA226EVM software has been tested on Microsoft® Windows® XP operating systems (OS) with United
States and European regional settings. The software should also function on other Windows OS platforms.
5.2 Software Installation
The INA226EVM software is included on the CD that is shipped with the EVM kit. It is also available through
the INA226EVM product folder on the TI website. To install the software to a computer, insert the disc into an
available CD-ROM drive. Navigate to the drive contents and open theINA226EVM software folder. Locate the
compressed file (INA226EVM.zip) and open it using WinZIP® or a similar file compression program; extract the
INA226EVM files into a specific INA226EVM folder (for example, C:\INA226EVM) on your hard drive.
INA226EVM Hardware www.ti.com
12 INA226EVM Rev A Model
User's Guide and Software Tutorial
SBOU113A – JUNE 2011 – REVISED JANUARY 2023
Submit Document Feedback
Copyright © 2023 Texas Instruments Incorporated

After the files are extracted, navigate to the INA226EVM folder you created on the hard drive. Locate the
setup.exe file and execute it to start the installation. Figure 5-1 shows the installation process.
Figure 5-1. INA226EVM Software Installation
After the installation process initializes, the user can select the directory in which to install the program; the
default location is C:\Program Files\INA226\ and C:\Program Files\National Instruments\. Following this option,
Figure 5-2 shows the two license agreements that must be accepted to continue the install. After accepting the
Texas Instruments and National Instruments license agreements, Figure 5-3 shows the progress bar that opens
and shows the installation of the software. After the installation process is complete, click Finish to close the
window.
Figure 5-2. INA226EVM License Agreements Figure 5-3. INA226EVM Software Installation
Progress
www.ti.com INA226EVM Software Setup
SBOU113A – JUNE 2011 – REVISED JANUARY 2023
Submit Document Feedback
INA226EVM Rev A Model
User's Guide and Software Tutorial
13
Copyright © 2023 Texas Instruments Incorporated

6 INA226EVM Software Overview
This section discusses how to use the INA226EVM software. Software operation involves a two-step process:
configuration of the INA226 settings, and operation of the tool.
6.1 Starting the INA226EVM Software
The INA226 software can be operated through the Windows Start menu. From Start, select All Programs; then
select the INA226EVM program.
Figure 6-1 shows how the software should appear if the INA226EVM is functioning properly.
Figure 6-1. INA226EVM Software Interface
INA226EVM Software Overview www.ti.com
14 INA226EVM Rev A Model
User's Guide and Software Tutorial
SBOU113A – JUNE 2011 – REVISED JANUARY 2023
Submit Document Feedback
Copyright © 2023 Texas Instruments Incorporated

Figure 6-2 shows an error that pops up if the computer cannot communicate with the EVM. If you receive this
error, first check to see that the USB cable is properly connected on both ends. This error can also occur if you
connect the USB cable before the SM-USB-DIG Platform power source. Another possible source for this error is
a problem with your PC USB Human Interface Device driver. Make sure that the device is recognized when the
USB cable is plugged in; recognition is indicated by a Windows-generated confirmation sound.
Figure 6-2. INA226EVM Software: Communication Error With the SM-USB-DIG Platform
6.2 Configuring the INA226EVM Software
The INA226EVM software first requires a series of setup processes to configure the device and ensure that it
works properly. On the Configuration tab (see Figure 6-1), there are six steps noted:
1. Set I2C Address
2. Configure Operation
3. Set Conversion Times
4. Select Configuration Method
5. Set Configuration Register
6. Configure Alert Pin
This section explains how to configure the software and reviews some of the different setups that can be done.
6.2.1 I2C Address Selection
The INA226 device has a flexible I2C address configuration that allows for multiple devices to be on the same
I2C lines. By moving the A0 and A1 addresses on jumpers J3-J6 to either GND, VS, SDA or SCL, the INA226
can be changed to a total of 16 I2C addresses as shown in Table 6-1.
Table 6-1. INA226 I2C Address Configuration
A1 A0 TARGET ADDRESS
GND GND 1000000
GND VS+ 1000001
GND SDA 1000010
GND SCL 1000011
VS+ GND 1000100
VS+ VS+ 1000101
VS+ SDA 1000110
VS+ SCL 1000111
SDA GND 1001000
SDA VS+ 1001001
SDA SDA 1001010
SDA SCL 1001011
SCL GND 1001100
SCL VS+ 1001101
SCL SDA 1001110
SCL SCL 1001111
Figure 6-3 shows how to configure the I2C addresses. Click either the A0 or A1 box and select how the hardware
is configured on the EVM. Failure to select the correct address prevents the INA226 device from communicating
with the software.
www.ti.com INA226EVM Software Overview
SBOU113A – JUNE 2011 – REVISED JANUARY 2023
Submit Document Feedback
INA226EVM Rev A Model
User's Guide and Software Tutorial
15
Copyright © 2023 Texas Instruments Incorporated

Figure 6-3. Setting the I2C Address
6.2.2 Configure Operating Mode
The second step of the INA226EVM configuration process allows the user to set the operating mode and the
averaging mode.
The operating mode allows the user to restrict the amount of calculations done within the INA226 by changing
the conversion to be triggered or continuous, or shutting down the part altogether. When the device is operating
in triggered mode, it only performs conversions when the operating mode is set and the Write All Reg button at
the top of the screen is selected. After the mode changes and Write All Reg has been selected, the Read All Reg
button must also be selected in order for the changes on the device to be reflected in the software.
When the INA226 is operating in continuous mode, conversions are performed directly after the previous
conversion is completed. When the INA226EVM software is in continuous mode, the software can be updated at
any time by pressing the Read All Reg button.
Power-down mode stops all conversions from taking place until the operating mode changes again. The device
remains attached to power but draws minimal current and does not perform any conversions.
Figure 6-4 shows how to limit all three operating modes to measure only certain components of the device. It
is important to note that for complete functionality of the INA226, a configuration must be chosen with Shunt
and Bus configuration. Failure to choose Shunt and Bus configuration disables a considerable portion of the unit
functionality as discussed in the INA226 data sheet.
Figure 6-4. Configuring Operating Mode
The Configure Operation step also contains a drop-down box to help the user select the averaging mode.
The INA226 can be setup to take the average of several measurements before storing the value of the
measurements in the register table.
INA226EVM Software Overview www.ti.com
16 INA226EVM Rev A Model
User's Guide and Software Tutorial
SBOU113A – JUNE 2011 – REVISED JANUARY 2023
Submit Document Feedback
Copyright © 2023 Texas Instruments Incorporated

6.2.3 Set Conversion Times
Setting the conversion times allows the user to customize the amount of measurement time for conversions.
Typically, for the INA226EVM software, the user is not able to notice a visual difference between the conversion
times unless a high averaging mode and conversion time are chosen. Figure 6-5 shows how to set the Shunt
and Bus conversion times.
Figure 6-5. Configuring Conversion Times
6.2.4 Set Configuration Register
The Configuration register must then be set correctly for the software to operate properly. There are two
methods used to set the Configuration register. First, the user can manually calculate the desired value and then
input that value into the register table, as shown in Equation 1. Alternatively, the user can allow the software
to create a recommended window and choose an LSB for the current as shown in Figure 6-7. Both methods
accomplish the same goal by using Equation 1, but the method is selected by changing the value in Step 4:
Select Configuration Method (as Figure 6-6 and Figure 6-7 show).
Calibration Register = 0.00512
Current_LSB RSHUNT
·
(1)
Use Equation 2 to calculate the current LSB by a recommended range in the INA226 data sheet. It is important
to note that with either of the methods used, the Current LSB and the Calibration register values are calculated
based on the other variable and the RSHUNT value. See the section, Programming the INA226 in the product data
sheet for more information on setting the Calibration register value.
Maximum Expected Current
212
Maximum Expected Current
215
£ £Current_LSB
(2)
www.ti.com INA226EVM Software Overview
SBOU113A – JUNE 2011 – REVISED JANUARY 2023
Submit Document Feedback
INA226EVM Rev A Model
User's Guide and Software Tutorial
17
Copyright © 2023 Texas Instruments Incorporated

Figure 6-6. Setting the Configuration Register
(Calibration Register)
Figure 6-7. Setting the Configuration Register
(Current LSB)
6.2.5 Configuring the Alert Pin
The Alert pin from the INA226 allows the user to set limits that monitor the registers and trigger a flag when they
are exceeded. The register that is being monitored can be changed by selecting the desired alert configuration
as shown in Figure 6-8. The value that is being considered is compared to the Alert Limit box. This Alert Limit
box modifies its functionality based on the selected configuration. It is important to note that by default, the
INA226 Alert pin is set to active low.
Figure 6-8. Configuring the Alert Pin
In addition to the INA226EVM software alert configuration, the Alert Configuration box includes the Conversion
Ready button that allows for a special functionality on the Alert pin. When the INA226 completes the conversions
for its current operation, it triggers the Alert pin and notifies the user that another conversion can be performed.
In most cases, the INA226 conversion ready flag is not visible because of the speed of the INA226 conversion
process.
6.3 Using the INA226EVM Software
After configuring the INA226EVM software, the rest of the tabs can be evaluated. This section describes the
basic operation of the device, and offers guidelines for interpreting the graphic user interface (GUI).
6.3.1 INA226 Bus Voltage, Shunt Voltage, Current, and Power Reading Bar
Figure 6-9 shows that the bottom bar of the INA226 software allows the user to constantly check the status of
the INA226 unit itself. These values are updated each time the Read All Reg button is pressed at the top of the
INA226EVM Software Overview www.ti.com
18 INA226EVM Rev A Model
User's Guide and Software Tutorial
SBOU113A – JUNE 2011 – REVISED JANUARY 2023
Submit Document Feedback
Copyright © 2023 Texas Instruments Incorporated

software. In addition to the register values stored in the part, the software also includes flags for when the part is
ready to trigger another conversion and when the Alert pin is triggered.
Figure 6-9. INA226 Results Bar
6.3.2 Calculation and Theory of Operation
The Calculation tab, as shown in Figure 6-10, allows the user to follow the software flow with basic calculations
performed from within the device. It is important to note that the calculations are performed with the decimal
values of the corresponding registers.
Figure 6-10. Theory of Operation Flowchart on the Calculation Tab
www.ti.com INA226EVM Software Overview
SBOU113A – JUNE 2011 – REVISED JANUARY 2023
Submit Document Feedback
INA226EVM Rev A Model
User's Guide and Software Tutorial
19
Copyright © 2023 Texas Instruments Incorporated

6.3.3 Register Tab
The Register tab contains information on the individual operation of the INA226 registers. Each register can be
changed on a bit-by-bit basis to allow the user to have total control of the device beyond the general functionality
of the GUI alone. Most of this functionality is displayed in the Configuration register tab, but if the user selects
the appropriate register and clicks the Help With Reg button on the Register tab, as shown in Figure 6-11, the
user can diagnose the individual uses of each bit in each register.
Figure 6-11. Registers Tab
INA226EVM Software Overview www.ti.com
20 INA226EVM Rev A Model
User's Guide and Software Tutorial
SBOU113A – JUNE 2011 – REVISED JANUARY 2023
Submit Document Feedback
Copyright © 2023 Texas Instruments Incorporated