For a basic test, I power the board up with no attached loads. I have a 12V AC/DC adapter that powers the 5V regulator. I have a 22uF capacitor at the output of the regulator, as the datasheet recommended this for stability.
When I plug this all in, I probe the voltage output of the regulator - it appears to work for a minute or so (holds a constant 5.0 V), then it rapidly drops to below 5V, and starts erratically pulsing. The FPGA stops performing and the LEDs on the board pulse.
My guess is that it's drawing too much current and overheating? The regulator is rated for 5A, which I figured was plenty for this application. The evaluation board doesn't seem to have a datasheet, but the FPGA does have a datasheet (download here).
Any thoughts as to why the regulator stops working? Any suggestions of a better method to provide the 5V to the board? I'd like to use the 12V AC/DC adapter as a power source if I can.