USB inventor explains why the connector was not designed to be reversible

Re:USB inventor explains why the connector was not designed ... by crote on Tuesday October 10, 2023 @04:57AM (#37829869)

> Ideally, the shield should be connected to the ground on one end

Depends on the signal. With low-frequency stuff (like audio) you want to ground the shield on one side to avoid ground loops, but with high-frequency stuff (USB 3, for example) you definitely want to ground the shield on both sides: if you don't, you end up creating an antenna which is really bad for your EMI performance.

USB 1.x happens to be at an in-between point where neither issue is a big deal. The connector spec literally says "use accepted industry practices", so either approach is fine if it manages to pass emissions testing.

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Re:USB inventor explains why the connector was not designed ... by klysm on Tuesday October 10, 2023 @08:26AM (#37831174)

That goes against all the guidance I’ve read, but I’m an amateur so you may be right. I’m confused on why it relates to signal speed though. For instance, I’ve read that this guidance also applies to Ethernet which is quite high frequency and based on differential pairs

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