Hi, I’m working with a microcontroller and need to measure the output voltage and current of a Buck converter. The converter doesn't have built-in telemetry, so I need to implement the sensing myself to calculate the load resistance.
My main concern is the output ripple. Should I use hardware-based low-pass filtering to get a steady DC value before the ADC, or is it better to sample the raw signal and handle the filtering/averaging via software?

I'd appreciate your advice on the best practice for this.

 

output of a buck converter is already filtered but you could of course add additional filtering before your ADC. depending on measured voltage you will need voltage divider. but... since you only care about ripple, it would be best to AC couple it and amplify it before sampling.

 

It seems to me that the TS is concerned about the ripple causing errors in the reading rather than measuring the ripple.
My siggestion is to filter the measurement signal voltages because that is simpler to verify that the actual calibration is OK. Softwre filtering requires more code.