a. This action effectively raises the absolute common-mode voltage of the input pins, while still retaining a
positive input differential signal.
3. Provide the desired reference voltage to the REF1 node for channel 1 or REF2 node for channel 2.
4. Measure the output voltage at OUT1/OUT1F for channel or OUT2/OUT2F for channel 2 with respect to
ground (GND) or with respect to the channel's reference voltage.
To configure a measurement evaluation with a shunt resistor, follow this procedure:
1. Solder a 1206 resistor at the Rshunt pads that connects to the IN+ and IN– inputs.
2. Connect the Rshunt tabs (J1n and J2n for channel 1 or J3n and J4n for channel 2) in series with the load
and bus voltage sources while powered off.
WARNING
Make sure that the equipment (shunt resistor, wires, connectors, and so on) can support the
amperage and power dissipation first before you measure the current. Also make sure that the
current flowing through J1n, J2n, J3n, or J4n does not exceed 5 A. Failure to do so can result in
hot surfaces (> 55 °C), damage to the EVM, or personal injury.
3. Power on the system and measure the output voltage at the OUT/OUTF test points for the correct channel.
Output voltage with respect to ground is equal to the gain of the device multiplied by the differential voltage
plus the reference voltage, where the differential voltage is the exact voltage from IN+ to IN– input pins.
Operation
6
INA2191EVM
SBOU254A – JANUARY 2021 – REVISED JUNE 2021
Copyright © 2021 Texas Instruments Incorporated
