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INA233: Monitor -12V using INA233

Part Number: INA233
Other Parts Discussed in Thread: INA282, INA226, ISO1541

Hello, I have a design which I need to monitor the current on a -12V supply. Can I still use the INA233?

I thought if I feed the -12V into the IN- pin then I would be able to measure the current.

Is this possible?

Thank you

  • Joe,

    Thanks for the question and using the E2E forum.

    Unfortunately the INA233 cannot be used in this way. The absolute maximum (or minimum in this case) common-mode voltage only goes down to -0.3V. So, using this device anywhere below this value could cause permanent damage. We actually don't have any digital power monitors in our portfolio that can withstand common-mode voltages down to -12V. However, we do have a few analog devices that could do this, if you could switch from a digital device to analog.

    Please let us know if you have any further questions.

    Louis

  • Hello, thank you very much. Can you recommend a device please?

  • Joe,

    Without knowing much more about your application, I wouldn't be able to give a good suggestion. Our online portfolio is a great place to start, and I've given you a head start by filtering down to the devices that will work with Vcm <-12V, just click here to find it. It is all dependent on your system requirements, but the INA282/3/4/5/6 family would be a great place to start since they can work down to Vcm = -14V.

    Louis

  • Thank you very much. Say would you happen to know of a device that has a I2C interface?

  • Joe,

    We don't actually have a device that can work down to your -12V Vcm requirement and uses the I2C interface.

    Louis

  • Okay, thank you very much.

  • Joe,

    There is another option you could look into. We have a reference design here using the INA226 and ISO1541 that extends the Vcm down to -48V. Although it uses the INA226, with some work it could be modified to use almost any of our digital power monitors if configured correctly.

    Louis