Antialiasing is not used on the output - usualy there is just a low pass filter to take out high frequency switching noise.
Antialiasing is done on the input side - say you are capturing data with at 20KHz sample rate - then antialiasing filter would be a filter that kept the input frequencies below 10 KHZ (since you need at least 2 samples to be able to recreate a waveform). This could also be a low pass filter.