The NI-9470 uses a hardware digital comb filter to average current ADC samples and reject noise at harmonics of the channel PWM frequency. The current readback samples returned in software are an average of all samples captured during each PWM cycle. Slower PWM frequencies will have more ADC samples in the average compared to faster PWM frequencies. The minimum number of samples used in an average is 32 samples when the per-channel divisor is set to one.