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Altera_Forum's avatar
Altera_Forum
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16 years ago

A question regarding MAX II I/O supply voltage

Hi everyone! Been searching the literature and googling around, but I've found no indication as to whether it is a problem to connect the VCCIO pins of the MAX II device to a non-standard volt...
Altera_Forum's avatar
Altera_Forum
Icon for Honored Contributor rankHonored Contributor
16 years ago

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I am expecting to see roughly a Vih and Vil of 0.65*Vccio and 0.35*Vccio respectively, and a Voh and Vol of 0.75*Vccio and 0.25*Vccio respectively.

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That's reasonable. MAX II I/Os are CMOS gates supplied by VCCIO, they have a slight threshold asymmetry to better fit the LVTTL requirements, but basically comply with respective JEDEC level specification over the 1.5 to 3.3V supply range.