Suggest me a digital isolator solution for isolating USB lines

Status
Not open for further replies.
M

manu.s

Newbie level 4
Joined
Sep 22, 2009
Messages
7
Helped
0
Reputation
0
Reaction score
0
Trophy points
1,281
Location
India
Activity points
1,337
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.
 

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
 

Re: isolating USB

What is max speed in any of 8 channels?
 

Re: isolating USB

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

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.
 


Status
Not open for further replies.

Similar threads

Menu
Log in
Register
Cookies are required to use this site. You must accept them to continue using the site. Learn more…