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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
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
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