> If a single ferrite bead is used it is not usually necessary to also have the separate beads as shown in Figure 8
Yup, it's probably cheaper to put a few small ferrite beads on the board than to put a big one on the cable.
Being a differential signal, I never understood why USB cables would _need_ them, but seeing it on a premium cable inspires the feeling that you bought a better product? I also think reduced 900MHz interference from cordless phones (remember those?) made homes quiet enough that the bead became more of a value-add for most applications. Just guessing...
> If a single ferrite bead is used it is not usually necessary to also have the separate beads as shown in Figure 8
Yup, it's probably cheaper to put a few small ferrite beads on the board than to put a big one on the cable.
Being a differential signal, I never understood why USB cables would _need_ them, but seeing it on a premium cable inspires the feeling that you bought a better product? I also think reduced 900MHz interference from cordless phones (remember those?) made homes quiet enough that the bead became more of a value-add for most applications. Just guessing...