EVM Components
7
SBOU218A – February 2019 – Revised April 2019
Copyright © 2019, Texas Instruments Incorporated
INA191EVM
4.7
U1x (INA191)
U1x is the location for the INA191Ax test device. Five device boards are supplied with the INA191EVM
board. Each board is populated with one of the available device gains. This option allows users to test the
devices and determine the gain setting that is best for a given application.
The following list of factors are involved in selecting the appropriate device:
•
The INA191 devices are identical with the exception of the different gain settings.
•
The differential input voltage is either applied across the inputs or developed based on the load current
that flows through the shunt resistor.
•
Make sure that the output voltage does not exceed the supply voltage. This limiting factor requires
attention to device selection.
•
The selected device must allow the output voltage to remain within the acceptable range after the
developed input voltage is amplified by the respective device gain. The output voltage must remain
within the device-specified swing limitations for response in the linear range.
•
An output below the minimum allowable output requires the selection of a device with a higher gain.
Likewise, an output above the maximum allowable output requires the selection of a device with a
lower gain.
4.8
J0x, J1x
J0x and J1x are 0.240-inch, noninsulated, quick-fit terminals that are designed to insert into similarly-sized
female receptacles. The kit provides two receptacles. Using insulated receptacles with J0x and J1x
terminals allows the user to make sure that there is a strong and safe connection between the current
source and EVM when dealing with high currents.
WARNING
If using the EVM to measure currents, make sure a proper power
resistor is soldered at the R3x pads. Also make sure that the
receptacles (connecting to J0x and J1x) and the respective
crimped wires can support the amperage of the current being
measured, and the necessary power dissipation. Do not exceed 15
A of current flowing between J0x and J1x. Failure to follow this
requirement can result in hot surfaces (> 55°C), damage to the
EVM, or personal injury.
Standard metal clips can electrically interface with these tabs for lower currents.
The Rs+ (J0x) and Rs– (J1x) inputs accept a differential voltage that is amplified by the selected device
gain, and is presented at the OUT test points (TP5x and S7x, if populated). These inputs can also be used
to connect the differential voltage developed across an external shunt in an existing circuit. The
acceptable differential input voltage range is determined by the supply voltage and gain of the selected
device.
