PORTS Forum

Ports and Interfaces => USB => Topic started by: jb on February 12, 2021, 12:25:03 pm

Title: Type-C cables connect GND and Shield, but adapters do not?
Post by: jb on February 12, 2021, 12:25:03 pm
USB Type-C Spec R2.0 - August 2019.pdf

For all the cables with plugs at both ends, it says


For the adapters with receptacles on one end, it just says:


So the Shield should not be connected to the grounds in these adapters?  Anyone know why?
Title: Re: Type-C cables connect GND and Shield, but adapters do not?
Post by: Jan Axelson on February 12, 2021, 01:25:05 pm
Just a guess, but perhaps the short length doesn't require it.
Title: Re: Type-C cables connect GND and Shield, but adapters do not?
Post by: jb on February 16, 2021, 04:10:31 pm
OHHHHHH there's an ECN! 

USB Type-C ENGINEERING CHANGE NOTICE
USB Implementers Forum
Form 20140811-ECN
Page: 1
Title: Adapter Assembly Shield Grounding Clarification
Applied to: USB Type-C Specification Release 2.0, August 2019

"All Ground return pins shall be connected together within the USB Type-C plug."

was changed to

"Shield and GND grounds shall be connected within the USB Type-C plug and USB … receptacle on both ends of the adapter assembly."

How frustrating that they don't just update the main document.
Title: Re: Type-C cables connect GND and Shield, but adapters do not?
Post by: Jan Axelson on February 17, 2021, 11:06:50 am
Thank you for posting this. I agree that updating the original docs would be useful.