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Altera_Forum's avatar
Altera_Forum
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15 years ago

VCCIO Voltage Change

Hi, I use EP3C10F256C8 chip , VCCIO set 1.8V , if other IO pin input set Hi(3.3V), result VCCIO change 2.2V? VCCIO set 1.5V , if other IO pin input set Hi(3.3V), result VCCIO change 2.2V?
Altera_Forum's avatar
Altera_Forum
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15 years ago

Hi Leo,

It is not aways easy to express yourself in a foreign language. I'm not a native english speaker and neither are you, I assume.

Your post is too cryptic for me. Could you please use some more words to clarify your question? Maybe then I, or other members of this forum, could be of help.

Anyway, I'll give it a shot:

CONF_DONE is an open-drain output. If use a pull-up to 1.8V, the voltage on this pin will remain below 1.8V.

If you use a pull-up to 3.3V, the voltage will rise above 1.8V, probably Vf,diode. I would not recommend this. It could damage your FPGA.

-- Ton