I am working on an 100BASE-FX (fiber mode) application and am considering the DP83630 PHY to interface to my molex SMI series fiber transceiver. The DP83630 datasheet indicates "In 100BASE-FX mode, the device Receive pins connect to an industry standard Fiber Transceiver with PECL signaling through a capacitively coupled circuit."
The reference design of the transceiver indicates that it supports LVPECL as does the DP83630. The sample schematic of the DP83630 indicates no AC coupling capacitors on the RD- and RD+ pins. The reference design of the tranceiver shows AC coupling capacitors and advises additional buffering depending on the input sensitivity of the PHY.
I cannot find any information as to the input sensitivity of the RD- and RD+ pins on the DP83630??? All the datasheet says is that the RD- and RD+ pins must be biased to 3.3 volts for correct operation.
Can any fiber PHY experts shed any light on this?
Thanks