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Altera_Forum
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8 years ago

FPGA to SFP

I have designed Cyclone V based FPGA board. But i have connected with Normal IO instead of Transceiver IO. I need to clarify, whether this will work or not. I have attached schematic ...
Altera_Forum's avatar
Altera_Forum
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8 years ago

Have you read the TI datasheet for this device? Specifically section 11.2.8 describes how to do AC coupled signal reception (which will be what you get from the SFP module output). Basically you need 50ohm pullups on both P/N to Vbb. Read the datasheet for all the details.

The TX input into the SFP will be just direct wires, as the SFP module is internally AC coupled and has 100ohm differential termination across P/N.

Note the 100ohm differential / 50ohm single-ended signal termination and routing means you adhere to those rules when designing the PCB trace layout, and implement the appropriate trace widths and spacing on your PCB to give you those trace impedances.