hi!
I have been using BOOSTXL-DRV8301 for BLDC motor control.
in the circuit schematic i saw that the current feedback (after the differential OPA stage) is fed into RC low pass filter and after the filter to the ADC .
if i understand it right the capacitor is there to supply high currents peak on adc conversion , and the small value resistor is used to keep the OPA stable. and this also forms low pass filter but with very high cut off frequency.
i have done pcb layout based on the BOOSTXL-DRV8301 and i see high frequency noise on my adc readings.
i saw that if for example i sample constant voltage and average the samples i get very good result ,so i added LPF in my software .
my question is if its a good practice to add this filter by software , and if yes can you please help me determine the cutoff frequency based on motor and control loop parameters
best regards
Mark