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Honored Contributor
Honored ContributorCyclone IV GX Tranceivers
I am trying to interface a tranceiver link to a fiber link. The fiber link expects lvpecl. How exactly would I interface that. The tranceivers on the Cyclone IV transmit 1.5 PCML, and th...
Altera_ForumHonored Contributor
Honored Contributor --- Quote Start --- I don't know. As a matter of experience though, ignore whatever 'standard' the data sheet description for a part says it uses, and look at the technical details in the datasheet. For example, I used a PLL part from Analog devices that says it has CML outputs. CML outputs should have pull-ups to the supply rail at the transmitter ... but this particular part does not ... so it was CML 'compatible' (with the addition of external resistors), rather than CML compliant. --- Quote End --- ^^ A very good advice. That said, PCML should be just another name for PECL. The voltage levels are higher than LVPECL but the voltage swing should be the same (0.8 V). LVPECL: low => 1.6V, high => 2.4V PCML: low => 3.4V, high => 4.2V
