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INA228: precisely measure current loops

FRANK1
Expert 8575 points
Part Number: INA228
Other Parts Discussed in Thread: INA260,

Hi sir,

I wanna use TI current monitor ICs.

Can the INA260 measure current more precisely than at 1.25mA increments?

If not could you recommend a better IC to precisely measure 4-20mA current loops and voltages of 0-10v sensors.

A higher voltage input would be an advantage (i.e. 24V). Must be I2C bus.

I also find INA228, It would be good if TI could confirm that IC would be appropriate to accurately sense a 4-20ma current loop at 24V.

And what shunt resistor would be appropriate for this application?

Thanks.

  • 0
    TI__Mastermind 26835 points

    Hello Frank,

    Thank you for using the TI forum. The INA260 would not be that great for your specific application.  If I put the system parameters into the error analysis tool (found near the bottom of the product page), I get these results:

    As you can see, the error is rather high.

    The INA228 on the other hand would be a much better fit (and is currently our most precise digital power monitor). With the same parameters, we get this expected error:

    As you can see, the error is significantly lower.  But that was with the same shunt that was in the INA260, you can get much better results with a larger shunt such as 100mΩ:

    I also recommend looking at the app note "Getting Started with Digital Power Monitors" found here: https://www.ti.com/lit/an/sboa511/sboa511.pdf

    The introduction also has a link to a design tool that can help you pick your shunt based on your specific system parameters.