How do PASSIVE HDMI to VGA Adapters work ?

[DnFx91]

Ok so this will likely get a bunch of people saying "NO IT DOES NOT WORK, YOU NEED AN ACTIVE ADAPTER" 
But that's wrong, it does work, sometimes...

 

Clearly VGA is analog, and HDMI is digital, however the internet is divided as to whether you can passively convert between the two standards. But i've seen it work plenty of times with my own eyes, including my current work laptop which drives a VGA monitor from its HDMI port with a legit HDMI to VGA cable, no adapter or active logic.

So im wondering, do certain GPUs actually have the ability to output analog over the HDMI port ? in my experience its usually laptops that can do it. And to add to the weirdness, i once had a laptop which would output analog VGA from the HDMI port when the GPU was running in "windows basic display adapter" mode, with no drivers. but when i installed the drivers, i then had to use an active adapter to get VGA from that same HDMI port.

 

TLDR;

You shouldnt be able to passively convert HDMI to VGA, but sometimes you can, why ?

 

 

 

 

 

 

[Kanna]

Well a passive adapter atleast the one i own it is from my knowledge  that passive works if u plug the hdmi in the device and vga in monitor it does glitch up sometimes so it wont post but if u plug the hdmi into a monitor and vga in a pc then i can’t use a passive and will need a active adapter

[Glenwing]

They're active adapters. The conversion circuitry is in the cable housing.