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Isolating LVDS signals

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Los Frijoles

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Lately I have been designing a device which requires an isolated high speed data link. I came across LVDS as how many high speed serial links are accomplished. However, I need to isolate it electrically from the receiving end and so I was wondering how that could be done.

I had an idea that one could use a 1:1 ratio balun like so since they are transformers essentially designed for higher frequencies, but I am not sure this gives enough isolation (I am going for a minimum of 500V isolation):
Code:
+LVDS----    --------
         )||(
         )||(
         )||(
-LVDS----    --------
LVDS      Balun   Receiver side
side            with terminating resistor (not shown)

I also thought of using conventional optoisolators or galvanic isolators, but isolators at the speeds I would like (100mbps or greater) either don't exist or are expensive (this is a hobby project with the goal being to keep costs down).

Any thoughts?
 

If you have a balanced high density data stream (like 8b/10b
continuous mode) this ought to be OK. In burst mode you'd
end up operating the receiver with shorted input, which some
receivers' failsafe modes will make a known output and some,
unknown.

The outputs will throw 4mA whether it's a winding or a resistive
load.

There are however digital isolation products that exist specifically
for this purpose. Check TI's new stuff in this line.
 

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