RobJ said:
Ian -
What FPGA family has that kind of LVDS output performance? Are you talking
about 600MHz clock or data outputs? Virtex-2 runs out of gas at around
400MHz for LVDS clock outputs (i.e., 800MHz data). I'd be really surprised
to hear that a Xilinx competitor can do 50% better than that.
Rob
Hi Rob:
That was a Virtex 2, two 15-bit channels interleaved to get the 1200MHz data
rate, 600MHz "clock" rate. ISTR the latest wheeze is the "Rocket IO" stuff.
I believe there's also some fast hardware for doing PCI Express arriving
real
soon now (tm).
John Larkin mentioned a requirement for 3V+ swings, I missed that. In an
earlier
post he also mentioned using an ECL driver - that can work _very_ well. It
can be advantageous to use differential signals if you need to transmit any
distance across your board (single ended can give you serious spur
problems).
If you use a beefy driver, and use, say, two 25-ohm or even less drive lines
with a balun right next to your load, that should give a decent swing.
John mentioned the ERA family from MiniCircuits, I've had occasion to use
some Watkins Johnson parts (AH11, AH101 etc) see:
http://www.wjcommunications.com/rf_components/amplifiers.asp
Look at the power dissipation, these puppies need decent thermals, and WJ
have paid lots of attention to this.
Regards
Ian
