[LAU] USB cable with ferrite core

[Clemens Ladisch]

Ralf Mardorf wrote:
>Saw + pincers = ferrite core removed = no xruns anymore

Thank you for doing the experiment.

>>2) Unfortunately, USB is inherently noisy. Using a ferrite to reduce
>>common-mode currents in the cable is, in principle, a good idea.

Using a common-mode choke works only for differential signals.
But USB also uses common-mode signalling for certain states.
Ferrites on a USB cable should be one per data line, and sized so that
only frequencies higher than the USB signalling rate are filtered out.

I would guess that that cable was (originally) intended for low speed only.


Regards,
Clemens