Forum Discussion

RDiva's avatar
RDiva
Icon for New Contributor rankNew Contributor
4 years ago

I/O Standard

Hello,

recently while working on a design with EP4CE30F29I8LN where all our I/O banks were powered to 3.3V and under device and pin options I had selected 3.3-V LVCMOS. However one of the I/O lines had to be adjusted for increased current strength from default 2 mA and also the slew rate. The only way I could do it was to change the I/O standard of one entire bank to 3.0-V LVCMOS and this made it work. Is this okay even though I externally connect to 3.3V?

Thanks,

Divakar

8 Replies

  • AminT_Intel's avatar
    AminT_Intel
    Icon for Regular Contributor rankRegular Contributor
    4 years ago

    Hello Divakar,

    I see you are using Cyclone IV on your design. Are you referring to Vccio? If yes, the range of Vccio in 3.0-V LVCMOS is from 2.85V to 3.15V. Supplying Vccio of 3.3V on this bank is not recommended since it is above the range and I cannot validate whether it will be safe or not to your device. I would recommend you to follow I/O Standard Specs from Cyclone IV Device Datasheet Table 1-15 page 12: https://www.intel.com/content/dam/www/programmable/us/en/pdfs/literature/hb/cyclone-iv/cyiv-53001.pdf .

    Thank you.

    • RDiva's avatar
      RDiva
      Icon for New Contributor rankNew Contributor
      4 years ago

      Is there a way I can get current strength greater than 2 mA when selected for 3.3-V LVCMOS

    • RDiva's avatar
      RDiva
      Icon for New Contributor rankNew Contributor
      4 years ago

      Can it damage the device? I see the absolute maximum rating is 3.45.

      • AminT_Intel's avatar
        AminT_Intel
        Icon for Regular Contributor rankRegular Contributor
        4 years ago

        Hello RDiva,

        Unfortunately no. The current strength from the table I shared with you is only from -2mA to 2mA for 3.3V LVCMOS. I am sorry I cannot validate if it will be safe for your device if you set specifications beyond our range from that document. Do you need any more clarification?

        Thank you.