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Altera_Forum
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14 years ago

5V i/O

Hello, I need to have TTL (+5V for HIGH) inputs and outputs from an Altera DE0 board. Is there any easy way to configure it for I/O pins to operate at 5V? Due to time constraint, I am try...
Altera_Forum's avatar
Altera_Forum
Icon for Honored Contributor rankHonored Contributor
14 years ago

I myself using DE0 with 5V ICs. You can send a 3.3V LVTTL signal to a 5V TTL, that's ok. But for taking 5V signals as an input I use a serial 330 ohm resistor to restrict current and a parallel 3.3V zener diode before FPGA input. Works satisfactory for me for low frequency applications.