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Hello,

I am currently working on a project with a Saxo board that is programmed in Verilog. I have the following problem: the more current I drive into the board, the more the FX2 chip becomes hot. It becomes very quickly extremely hot, when using only a few pins of the Saxo board! Is that normal, or do you know where this heating comes from?

Moreover, I was thinking about using an external power supply instead of the USB2 power: do you think that it will help to get rid of the heating of the FX2 chip?

Thanks a lot for your answers!

The FX2 should stay cold.
Can you explain what you mean by "the more current I drive into the board" ?

I've tried to power the board externally and it takes 1A for a 5V power supply. Is that ok?

If I need to increase the power consumption (I want to increase the number of channels I use to drive TTL logic), by how much do you think it is possible to increase the current without damaging the board and the Altera chip?

Thanks for your answers!

No it is not ok, it should take something like 100mA when it is idle.

To clarify, it takes about 100-200mA when it is idle.
What I meant is that when I start driving external TTL devices (all terminated with 50 Ohms), and use 10 FPGA pins for that, I get the consumption of ~750mA. I might need to use another 10 pins for the similar job and I figure that the consumption should roughly double. The question is what is the highest current the board and the FPGA chip will take safely.

Thank you in advance.

Ok.
My guess is that it is the 3.3V voltage regulator that heats up, not the FX2.
Could you power the 3.3V supply rail instead of the 5V? This way you bypass the voltage regulator. It is rated 800mA so you may have reached the limit already anyway.