Texas Instruments INA229 User Manual page 13

www.ti.com
5.2.2 Current Sensing Operation
The EVM allows the user to either emulate the voltage developed across a sense resistor based on a given set
of system conditions by applying a differential voltage across the IN+ and IN– terminals directly, or to connect the
device inputs to an external shunt. Optionally, a 2512 surface-mount technology (SMT) shunt resistor can be
soldered across the pads of R1, and these inputs can be connected in series with the external system and load
current. There are two terminals each for IN+ (J1 pins 5 and 6) and IN– (J1 pins 3 and 4) for convenience.
5.2.2.1 Without Shunt Resistor
To configure a measurement evaluation without a shunt resistor, follow these steps:
1. Connect a differential voltage across the IN+ and IN– terminals as shown in
a. If the differential voltage supply is a floating supply, connect a –0.3-V to 85-V common-mode voltage
(leave powered off until finished setting up) to the inputs by connecting the positive lead of the external
voltage source to either the IN+ or IN– terminal. This action effectively raises the absolute common-mode
voltage of the input pins. Make sure that the differential voltage plus or minus the common-mode voltage
does not go out of the –0.3-V to 85-V range.
2. Connect the VBUS terminal (J1 pin 2) to the desired bus voltage (likely either IN+ or IN–).
3. Connect the source ground to the GND terminal (J1 pin 1).
4. Power on the system, and observe the device states and outputs through the GUI.
SBOU241B – APRIL 2020 – REVISED DECEMBER 2020
Submit Document Feedback
Figure 5-10. IN+ and IN– Wiring Without a Shunt Resistor
Copyright © 2020 Texas Instruments Incorporated
Figure 5-10.
INA228, INA229, INA237, INA238, and INA239 EVM User's Guide
Operation
13