Forum Discussion

Altera_Forum's avatar
Altera_Forum
Icon for Honored Contributor rankHonored Contributor
15 years ago

Cyclone III with 5v inputs

I'm trying to connect approximately (16) 5v TTL inputs into a Cyclone III eval board, the terasic de0 [1]. These are all input towards the FPGA only. The eval board has (2) 40-pin IDC headers for t...
Altera_Forum's avatar
Altera_Forum
Icon for Honored Contributor rankHonored Contributor
15 years ago

--- Quote Start ---

Might be worth a follow-up email with Terasic to verify - or just check the board for a whole bunch of 3-terminal diodes near the connectors.

--- Quote End ---

So I did both.

--- Quote Start ---

There is not any protection diodes for the free GPIO pins, so we do not recommend our customer to import the 5v TTL into the board. If you have to, please try to decrease the input voltage to 3.3v to avoid damage the board, thank you!

--- Quote End ---

and from visual inspection, there's definitely nothing there.

Thanks

Keith