The .000001% of use cases for a simple passive VGA to HDMI is for when the video source is designed especially to output both VGA and HDMI. In these cases the cable will accompany the video source when you buy it. This is so rare, I almost regret writing this much about it. Analog vs Digital.
Definition - What does Pulse Width Modulation (PWM) mean? Pulse-width modulation (PWM) is a modulation process or technique used in most communication systems for encoding the amplitude of a signal right into a pulse width or duration of another signal, usually a carrier signal, for transmission.
SecurActive Performance Vision. Modulation is the addition of information to an electronic or optical carrier signal. A carrier signal is one with a steady waveform -- constant height (amplitude) and frequency. Frequency modulation (FM), in which the frequency of the carrier waveform is varied to reflect the frequency of the data. 2  Phase modulation (PM), in which the frequency of the carrier waveform is varied to reflect changes in the frequency of the data (similar but not the same as FM).