The International Rectifier discussion is excellent, but the embedded link doesn't use the term "digital" in the generally accepted manner, and some might say is simply incorrect. Pulse Width Modulation of a continuous analog waveform doesn't involve any digital sampling, and although the max/min appearance of the PWM waveform has been said to be "digital-like" in appearance, it's still just a modulated continuous analog waveform. The analog waveform "concealed" within the PWM waveform is revealed when the low-pass filter removes the PWM frequency and its harmonics, leaving the original analog waveform.
