Part Number: INA228
Hi TI Team,
I am using the INA228 for current sensing with a convversion time of 50 us and an output averaging setting of 1. According to the datasheet, the noise-free ENOB under this configuration is 12.4 bits. I therefore expect the lowest 8 bits of the shunt voltage register to exhibit random noise.
However, I observe that the readings from the shunt register are not continuous. with a 0.1ohm shunt resistor, the step change between consecutive readings is approximately 78-80 LSBs. When I switch to a 15ohm shunt resistor, the step interval increases to roughly 213-216LSBs.
Could you please explain why the step intervals vary so significantly with different shunt resistor values, and why the data does not change in a continuous (1-LSB) fashion as expected?
I have attached the schematic and a sample of the captured shunt register data for your reference.
Thanks for your support.
