Power Supply for Xilinx FPGA

Derek, Hmmm, what input power do you have? Are you any good at PCB layout? How many are you making? Why are you using Virtex-E? Have you ever been in a Turkish prison? Whatever, my current (ha ha) favourites are LT parts. I've got a good FAE! LTC3728 is a dual controller can take up to 24V in and make 5V and 3.3V. I use LTC3414s to make core voltages from these supplies. LT do demo boards for both parts. Be environmentally friendly, ditch the evil linear regulators, use switchers! Especially as you can get 6.3V 100uF X5R ceramic in a 1210 package these days. And check out Panasonic's specialty polymer electrolytics. Bloody marvellous, 5 milliohm ESR. Cheers, Syms.

national

XCV405E, XCV300E ... it looks like small FPGAs. I don't know if it will help but on the other range of the Xilinx Family (Virtex-II and Spartan-3 > 1Mgates), we use Texas Instruments DC/DC converters (search for Swift Technology) to generate the various supply voltages. The main advantage is to have a power conversion efficiency around 90% and therefore not to dissipate that much power during the conversion itself (which is nice if you have to supply a few A).

Moreover, they have a software tool that you can douwnload which will give you the schematics around the converters (capacitances, resistors, ...) as well as the precise references of all active/passive components. I've no interest in supply voltage and therefore this tool makes the job a lot easier :-) All the boards that we have designed work pretty well w/ it.

Eric

Both TI and National (maybe Intersil too, I forget) have a bunch of material geared to helping design power subsystems for xilinx FPGA parts.

IMHO, LTC has nice stuff and good apps people, but the parts are just too expensive.

Check out the Fairchild FAN5286 - dual switcher controller with wide input range, DDR Vtt support and its something like $1.50 on their web site. We got a fair bit better than that with a real quote through distribution. There's even an Intersil part that's close to a drop in replacement (pinout is the same, I haven't recalculated the L's, R's and C's).

The only thing I don't like about it is it requires a +5V rail, it doesn't have the internal regulator like some others.

Derek,

I am currently developing dual-voltage POL specifically to power FPGA's. Reduce your time to market and use an off-the-shelf, highly-efficient, pre-engineered power supply. It is very configurable but as a maximum can supply 2 different rails of 3A each as well as a third rail of 250mA. As a bonus a Xilinx platform flash is optionally included if you want.

I am targeting Spartan-3 device initially but there is no reason why it won't work with any FPGA or DSP.

Email me if you want more specific information.

There will be info shortly at

Cheers,

James.