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Altera_Forum
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18 years ago

explaination of table 3 of appnote 447

I dont understand table 3 of appnote 447. The 3.3v row and 3.3v TTL column... The table says that if the driver is capable of 30mA or less at Voh of 2.4v then all is good. How does this relate back...
Altera_Forum's avatar
Altera_Forum
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18 years ago

The answer to your second question is that the input buffer powered by VCCIO = 2.5V is 3.3V tolerant. And coupled with the information below

Also, re-read the text in the first paragraph "When the bank supply

voltage (VCCIO) is 2.5-V or 3.0-V, the diode can sufficiently clamp

overshoot voltage to within the DC and AC input voltage specification.

As for 3.3-V VCCIO, voltage may be clamped to a level exceeding the DC

and AC input voltage specification considering the ± 5% supply voltage

tolerance."