I would like to sense an output 98W (20V/4.9A) and should control in range 96W~100W by sensor ICs
Which is my chosen INA300/INA233/INA226
1. Can INA226 & INA233 do it?
2. How to calculate the accurracy in INA226 & INA233?
3. In datasheet - INA300, I discovered accurracy parameters
Maximum measurement error:5% (How did it be calculated?)
Hello Adrian,
1. Can INA226 & INA233 do it?
The INA226/INA233 can measure a maximum of 81mV, so if your shunt resistor value is less than 16.7mΩ you will be able to measure the full current range of 4.9A. The maximum Vbus input is 36V, well within your expected 20V. Therefore, this situation will be fine for the INA226/INA233.
3. In datasheet - INA300, I discovered accurracy parameters
Maximum measurement error:5% (How did it be calculated?)
It looks like you are looking at the "selecting a current sensing resistor" section of the INA300 datasheet. The "Maximum measurement error" in this example is a design constraint, not a value calculated from the device. If you have a particular accuracy specification you need to meet you can follow a similar procedure to the one outlined in section 7.3.1 of that datasheet for your design.
2. How to calculate the accurracy in INA226 & INA233?
The accuracy of the INA226/INA233/INA300 is dependent upon many factors, including the shunt resister chosen and the operating conditions it operates under. You can see some of these factors in section 7.3.1 of the INA300 datasheet. You can also calculate accuracy using the videos here: https://www.ti.com/video/series/ti-precision-labs-current-sense-amplifiers.html. Videos you might find especially helpful are the "How to choose a shunt resistor" video in the "Current sense amplifier applications" section and the videos on "Error sources".
Let me know if you have any more questions about how to use these devices.
Levi DeVries
