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Altera_Forum's avatar
Altera_Forum
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16 years ago

Produce 5v output?

Hi all,

I am using expansion header on my DE1 FPGA board to output my pwm signals. However, the output signals are 3.3v only. How do I set it to output 5v? I can't seem to find it in pin assignment as most of it shows 3.3v. Is it possible to output 5v or I must use some voltage level shifter? Thank you in advance.

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  • Altera_Forum's avatar
    Altera_Forum
    Icon for Honored Contributor rankHonored Contributor
    16 years ago

    Except for a few legacy devices, Altera programmable logic is limited to 3.3V I/O voltage. The I/O cells also aren't 5V tolerant. To achieve 5V output, you need level shifters. The 3.3V LVCMOS I/O standrad can however drive 5V TTL with a sufficient high level. Many 5V supplied logic devices and peripherals can be reliably operated this way.