How to INA210 to current sense negative rail?

[Now_and_Zen]

How to use INA210 to current sense negative rail?

Hi,

I'm building a dual rail psu with +/-12 volt rails, max 2A per rail output. I'd like to build current sensing into both positive and negative rails, I've chosen INA210 zero drift shunt monitor on cost/performance basis.

It is suitable for high side and low side measurement, but I'm not sure how to wire it to get a positive output voltage (need 0-5V) when connected to a sense resistor on the negative rail. Is this possible?

LT6105 works fine in this application but is a larger package and slightly more expensive.

Thanks,
Allan

 

[kam1787]

would not 'reversing' IN+ and IN- work?

 

[Now_and_Zen]

No, because -ve supply is below the common mode range. Reversing in+ and in- seems to work in sim if I connect gnd to neg rail though.

 

[kam1787]

how precise do you need?

how to display ?