Hi E2E,
I'm using CS comparison and error tool but it is not working on our latest MS office.
Could you replace it with newer version or help me to calculate the error under this particular case?
I need a comparison between INA230/INA232 as conditions below. Thanks in advance.
Izzy,
Thanks for the question and using the E2E forum.
Apologies for your challenges, we'll look into it from our side and see if there's a bug for using the calculator in a newer MS Office application.
Below you can find the analysis you requested between the INA230 and INA232.
Please let us know if we can help with anything else.
Louis
Izzy,
Measuring low current levels becomes challenging because as the voltages get lower and lower, they start to approach the offset errors of the device. At 0.2A, ~400uV is being measured across the shunt (using the 2mΩ value from your inputs). The INA232 inherently has a maximum of 50uV of offset, so over 10% of the measurement at that level could be attributed just to the offset of the device. The only way to improve the accuracy at the lower current levels would be to increase the shunt resistor value, thus increasing the sense voltage being measured by the device. However, that also comes with potential drawbacks like lower maximum current measurement capability, higher resistor noise, and power dissipated by the resistor itself.
The maximum sense voltage the INA232 can handle is +81.92mV (with ADCRANGE = 0). To measure the 7A maximum, the largest shunt resistor could only be 11.7Ω.
Using your same example, if the Rshunt were increased to 11mΩ instead of just 2mΩ, the error at 0.2A would be ~1.28%.
Louis
