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Altera_Forum
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11 years ago

DC-Coupling LVDS Tx to PCML Rx (Cyclone IV GX)

I want to use a Cyclone IV transceiver input to receive a LVDS signal (about 800Mbps over 50cm cable). I need to use DC-coupling as the signal is not DC balanced. Because of the Vcm requirement...
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Altera_Forum
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11 years ago

One more idea, since you cannot voltage-divide the LVDS common-mode, you need a level translator to either PECL or LVPECL, and from that output you can use a voltage divider to define the common mode voltage. Eg., scroll down to the PECL to LVDS example ...

http://www.eetimes.com/document.asp?doc_id=1225744

and in this TI app note

http://www.ti.com/lit/an/scaa056/scaa056.pdf

You should be able to build sometime similar for LVDS->LVPECL->PCML.

Cheers,

Dave