INA233 read current instable issue

Hello Jimmy,

The reason for this behavior is simply due to Gaussian noise with the load current. Increasing the number of averages will begin to digitally filter out noise in the load current. This is similar to increasing conversion time as seen in Figure 24 of datasheet.

The amount of noise in the INA233 measurement will get worse if you have chosen a very small current LSB value as well.

If you think the noise is outside of spec and need an analysis, then you need to consider how to determine the true noise of the load current using some much less noisey instrumentation or devices and consider the thermal noise of the shunt.

Adding an input filter with a capacitor as close as possible at the input pins of INA233 will also aid in low-pass filtering high frequency noise.

Hope this helps.