Author Topic: Type-C cables connect GND and Shield, but adapters do not?  (Read 66 times)

jb

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Type-C cables connect GND and Shield, but adapters do not?
« 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

  • "All Ground return pins shall be connected together within the USB Type-C plug."
  • "Shield and GND grounds shall be connected within the plugs on both ends of the cable assembly."

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

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

So the Shield should not be connected to the grounds in these adapters?  Anyone know why?

Jan Axelson

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Re: Type-C cables connect GND and Shield, but adapters do not?
« Reply #1 on: February 12, 2021, 01:25:05 pm »
Just a guess, but perhaps the short length doesn't require it.

jb

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Re: Type-C cables connect GND and Shield, but adapters do not?
« Reply #2 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.

Jan Axelson

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Re: Type-C cables connect GND and Shield, but adapters do not?
« Reply #3 on: February 17, 2021, 11:06:50 am »
Thank you for posting this. I agree that updating the original docs would be useful.