Forum Discussion
Altera_Forum
Honored Contributor
Honored ContributorVCCIO 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_ForumHonored Contributor
Honored Contributor --- Quote Start --- Furthermore, a similar specification of a Vih,max value can't be found with any other logic device, I think. Personally, I won't take the specification too seriously, but don't suggest to ignore it, of course. --- Quote End --- I checked the Cyclone III, Cyclone IV and Stratix IV specifications, which I all used recently, and they all define Vih,max. They also define an overshoot voltage of 3.95 or 4V, for 100% of the time. I'm willing not to take these specification too seriously, but I also don't want to take too much risk, so I still wonder if someone knows the answers to the previously asked questions: --- Quote Start --- So in the most worst-case situation at VCCIO of 1.2V, can I set my input to 3.95V for 100% of the time without damaging my component? May I pull-up the opendrain CONF_DONE to 3.95V if VCCIO is 1.2V? --- Quote End --- Thanks, Ton
