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INA2191: current measurement for +/-20 power supply

Oscar Rivera
Prodigy 50 points
Part Number: INA2191

Hi,
I am planning to use this device with a shunt resistor for measuring a 20V and -20V power supply current.
is the circuit below correct?

what I don't know is or if this is ok for the measurement of the current the negative voltage ?

best regards

Oscar

  • +1
    TI__Expert 5570 points

    Hello Oscar,

    Thanks for the question and using the E2E forum.

    Unfortunately the INA2191 is not designed to work with negative common mode voltages of this magnitude. Your channel 1 will work, but channel 2 will not. While the device won't be damaged (it can survive down to -42V), it will not produce the results you want because the minimum recommended operating condition of this device is -0.2V, listed in Table 6.3 and Section 7.4.1 of the datasheet.

    We have several devices that will work down to -16V, and a couple that will work down to -22V. I've sorted them here if you'd like to see if any of them will work for your application.

    Please let us know if we can help with anything else.

    Louis