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Altera_Forum
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12 years ago

Altera DE2-115 maximum GPIO current

Hi, I've tried searching the forums for an answer to this question to no avail. As I have seen in the quartus 2 tool the GPIO pins have a maximum current strength of 8mA or 16mA. Am I right to...
Altera_Forum's avatar
Altera_Forum
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12 years ago

Ganging outputs to drive higher currents is possible, but you must take care. There is a "switch through" current that can be just a big of an issue if you don't have the outputs timing closely matched. (There will always be some)

In Practice, what will happen is the output will not be able to reach the VOH levels, with the higher current draw. This may also damage the output depending on the duration due to thermal heating or metal migration issues.

35 mA is more than I would risk on a single output. I would tend to put an external driver or drive transistor in this case.

Pete