03-22-2010 08:43 AM
03-22-2010 09:11 AM
03-22-2010 10:13 AM
what about 4.5 volt ?
What are you trying to prove?
03-22-2010 10:29 AM
If you're interested in using a board outside of the recommended specifications, have you considered looking at the schematics and figuring out where the 5V input goes?
Different boards have different configurations for wall-wart supplied power. You haven't specified which "Virtex 5 kit" you have so we can't do the work for you by finding the schematics which are (usually) readily available to anyone (including you).
If the only things connected to the 5 volts are other regulators, you might be able to use an extended range but you really need to check every device for acceptable input range for the output voltages used.
03-22-2010 02:18 PM
that is the problem i recevied a kit from the faculty's lab without any accessories or cables or manuales
the only thing that i can give you is to send you group of photos to the kit may be you can identify it
03-22-2010 02:49 PM
Nu Horizons has two Virtex-5 boards that look like what you have, one for the FXT, one for the LXT device. I'm not sure from the photos which device you have on board. Both boards have very common power circuitry, though.
A quick scan shows the absolute minimum voltage for the LTM4601 is 4.5V and the maximum operating voltage of 5.5V for the LTC3026 LDOs (with an absolute maximum of 6.0V).
At 6V nominal input, you could fry the LDOs. At 4.5V nominal input, you could have marginal output voltages on your switcher module. You might be able to "work" between an absolute range (not nominal) of 4.5V to 5.5V having just looked at the power devices. There may be more devices powered by the 5V rail.
I'd suggest you just stick with 5V. If you're trying to run from a battery pack (hence the 1.5V multiples) you might be disappointed by the current draw of your board. If that is the route you're going, use a 6V battery pack and regulate down to 5V with an LDO that can handle the board current. Even then, you might fall out of regulation when the batteries are more than half full. You really should try to get an A/C supply hooked up.
03-22-2010 03:02 PM
thanks a lot you've been a great help
can you give me any link to this kit documentation ?
03-22-2010 03:10 PM
Choose which Virtex-5 kit is appropriate from this page:
They look like the same board but they target different parts. Look closely at the label on your Xilinx chip to determine which you have: FXT or LXT.
03-22-2010 03:59 PM
03-22-2010 04:13 PM