Datasheet

INA3221EVM Hardware Overview www.ti.com
Table 4 summarizes the function of the INA3221 test board jumpers. For most applications, all jumpers
should be left in the respective default configurations.
Table 4. INA3221EVM Test Board Jumper Functions
Jumper Default Purpose
J1 GND These jumpers select the I
2
C A0 address selection. Four separate I
2
C addresses can
be selected, depending upon whether J1 is set high or low or whether J2 is set to SDA
J2 Open
or SCL.
This jumper selects whether the INA3221 DVDD pin is connected to the V
DUT
signal
generated from the SM-USB-DIG platform or whether the digital supply pin is
J3 INT
connected to terminal T2, allowing for an external supply to power the digital circuitry.
The default INT position connects the DVDD pin to the V
DUT
control signal.
3.6 INA3221EVM Features
This section describes some of the hardware features present on the INA3221EVM test board.
3.6.1 J3: I
2
C V
S
Control Setting
Jumper J3 selects what the INA3221 supply pin is connected to. If J3 is set to the INT position, the VS pin
is connected to the switchable V
DUT
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 J3 is set in the INT
position, the VS Power button in the INA3221EVM software is able to control whether the V
DUT
supply
voltage is turned on or off. When J3 is set in the EXT position, an external supply connected to terminal
T2 can be used to provide the INA3221 supply voltage.
3.6.2 J1 and J2: I
2
C Address Hardware Setting (A0)
Jumpers J1 and J2 are used to set the hardware setting for the A0 I
2
C address pin on the INA3221. Using
J1, the A0 address can be set to either a logic '1' or a logic '0'. Using J2, the A0 address can be set to
either the SCL or SDA communication line. Make sure to only have either J1 or J2 connected individually;
failure to keep these lines separate can lead to board shorts and problems with the I
2
C communication
lines. See Section 5.2.1 on how to configure the INA3221EVM software to match the J1 and J2 hardware
setting.
3.6.3 External I
2
C Lines and Terminal Block T1
The INA3221EVM I
2
C communication lines are tied to two sources: the internal I
2
C communication lines
from the SM-USB-DIG and 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 INA3221EVM board and hook up the
necessary SDA, SCL, and GND lines. Also, remember to apply an external DVDD to the lines compatible
with the I
2
C communication device being used.
NOTE: Failure to disconnect the SM-USB-DIG while using external I
2
C communication can cause
damage to the SM-USB-DIG or any connected external communication devices.
10
INA3221EVM Evaluation Board and Software Tutorial SBOU126–April 2012
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