Electrical Isolation of USB Data-lines

[Fabian Kohler]

Hi volks,

I need a galvanic isolation of USB Datalines D+ and D- with speeds up to
2 Mbps (better: 5Mbps).

I thought about the Burr-Brown (TI) ISO150 bidirectional digital
coupler. But with 80 Mbps it is rather slow considdering the 480Mbps USB
2.0.

So my questions are:
0.) Is this the right board or is there a better one?

1.) Can I buy that? Or do I have to build it?
2.) What does USB 2.0 do when it is physically slowed down to 80 Mbps?
(I don´t even want to know what bit-noise comes through the ISO150
when my PC tries to communicate with 480 Mbps...)
3.) Has somebody already tried to isolate USB Data Lines or similar
fast bidirectional datalines?
4.) If I can use the ISO150, how can I derive the signal which sets the
direction-mode of the Coupler from the datasignal? Unfortunately
the ISO150 is bidirectional, but does not know by itself, when it
has to switch to which direction...

I am happy with any suggestions

Kind regards and greetings from Aachen,
Fabian

 

[Roger Hamlett]

Hi volks,

I need a galvanic isolation of USB Datalines D+ and D- with speeds up to
2 Mbps (better: 5Mbps).

I thought about the Burr-Brown (TI) ISO150 bidirectional digital
coupler. But with 80 Mbps it is rather slow considdering the 480Mbps USB
2.0.

So my questions are:
0.) Is this the right board or is there a better one?

1.) Can I buy that? Or do I have to build it?
2.) What does USB 2.0 do when it is physically slowed down to 80 Mbps?
(I don´t even want to know what bit-noise comes through the ISO150
when my PC tries to communicate with 480 Mbps...)
3.) Has somebody already tried to isolate USB Data Lines or similar
fast bidirectional datalines?
4.) If I can use the ISO150, how can I derive the signal which sets the
direction-mode of the Coupler from the datasignal? Unfortunately
the ISO150 is bidirectional, but does not know by itself, when it
has to switch to which direction...

I am happy with any suggestions

Kind regards and greetings from Aachen,
Fabian

There are a lot of off the shelf solutions to this.Look for 'opticis', who
make fibre optic cable links. The normal method, is to have a USB hub chip
at each end, which then gives access to the direction control line,
allowing two seperate unidirectional transceivers to be used.

Best Wishes