I'm wanting to current sense a 10A load with high precision. I'm planning to use a current shunt resistor and then amplify/filter this signal before sending it to an ADC. Which design flow is typically more precise?
- Using a high precision differential op-amp (amplify + level shift) -> buffer -> RC filter -> ADC
- Using an RC filter -> internal PGA of an ADC to amplify the signal, for example, the ADS131M02IPWT, datasheet
The intuitive answer is #1, but then I'm wondering why most ADCs have a PGA stage, because it's good enough for the typical application?