Drive electo-optic modulators with FPGA

Question

I am currently using an FPGA (Virtex II NI RIO7831R) to generate the clock for a pulse generator used to drive a Linbo3 optical phase modulator. http://www.jdsu.com/en-us/Optical-Communications/Products/a-z-product-list/Pages/modulator-ape-phase.aspx#.VXmz-0YpoiI

I would like to directly use the fpga to drive the modulator in real time but i need to generate up to 10 volt square wave with rising time less than 5/10 ns.

Does someone has an idea how to generate a square wave with such a fast rise time?

Than you in advance

Answer 1

While I may have misunderstood your drive requirements, a MOSFET gate driver would seem to be a good place to start. TI makes a line http://www.ti.com/lsds/ti/power-management/gate-driver-products.page#p9=3.2;5.3&p528=4;6&p529=12;14&p248=1;7.6&p598=TTL and a UCC27611 seems a decent choice. 5 nsec rise and fall times, and 10 volts into 50 ohms is .2 amps, while the IC will do .3 amps average. It comes in a very small package, too. And lots of other manufacturers make something similar, so I'm not specifically recommending this one, just using it as an example.

Answer 2

Depending on how much current the modulator requires, one solution might be a current feedback op amp. There are a number of high slew rate op amps with slew rates just about where you want it. One possible part is the LME49713. It's a current feedback op amp with 132 MHz of bandwidth and 1900 V/us slew rate. It should be possible to get a 10V swing in 10 ns out of that thing.