Suggest me a digital isolator solution for isolating USB lines

[manu.s]

Please help me in clarifying the following query.

In one of my application i need to provide electrical isolation for high speed (480Mbps) USB2.0 lines.
As there was no dedicated high speed USB isolators available in market, i am planning to isolate the external USB2.0 transceiver.
Here we need to provide isolation for the ULPI interface signals, which includes 8 bidirectional data lines.
Is this approach work with any available digital isolator solutions?
Please respond with your comments.

 

[esdk]

Re: isolating USB

Hi Manus,

There do exist HighSpeed Isolators - but they are quite expensive.

Yes it would be possible to do on the ULPI - but it needs a FPGA implementation to control resistor and direction. Not an easy one - but possible.
NOTE: That if you want USB hispeed logo - its a nogo with isolation on USB - isolators are too slow - the delay introduced is calced as one hub - hence no USB HiSpeed Logo.

Most either go for USB fullspeed or does the isolation after the USB device handling.

Fullspeed USB isolator: https://electronics-shop.dk/usb-isolation

It is using the FullSpeed adum4160, an isolated powersupply and ABS plastic.


Best Regards

Soren
Electronics-shop.dk

 

[hakeen]

Re: isolating USB

What is max speed in any of 8 channels?

 

[manu.s]

Re: isolating USB

The maximum speed for 8 channels will be around 60Mbps each.

 

[hakeen]

Re: isolating USB

In this case I don't think you can use the above mentioned part number. It is typical 12Mbps for fullspeed. It is too slow.

A normal digital isolator can work here,as they can do up to 125Mbps. But if you really seperate a HV side from LV circuitry (i.e. voltages difference between pri and sec sides is few hundred volts) then a digital isolator would be too weak to handle such high voltages. In this case I could recommend a Fiber solution. I know it is expensive, but it is much safer than digital isolators (i.e. non-optical) in this case. A plastic fiber solution would be also relatively cheaper option for any fiber solution.

 

[Kripton2035]

isolating USB

you could use this part from analog :

https://www.analog.com/en/interface/digital-isolators/adum1400/products/product.html

it can achieve a 90Mbps transfert rate, and you can use it on your digital 8 channels port, instead of the usb port.
you still have an isolation, at another place but this could work ?
regards,