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Zak's avatar
Zak
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5 years ago
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Cyclone V - LVDS input on a bank with Vccpd=2.5V and Vccio=1.8V

Hello,

I'd like to have a confirmation of what I found on the Cyclone V Device Handbook regarding mixed voltage standards on a single bank.

In my design I have multiple I/Os @ 1.8V and LVDS inputs on the same bank. Quartus doesn't issue any errors and the project compiles and fits successfully. I've done this because on the Handbook (Table 5-9: Cyclone V I/O Standards Voltage Levels) it's specified that LVDS inputs are only dependent to Vccpd, which is equal to 2.5V on my bank. There's also a note which says: "Input buffers for the SSTL, HSTL, Differential SSTL, Differential HSTL, LVDS, RSDS, Mini-LVDS, LVPECL, HSUL, and Differential HSUL are powered by VCCPD".

Can someone confirm that?
Thank you

  • ShafiqY_Intel's avatar
    ShafiqY_Intel
    5 years ago

    Hi Zak,

    There is no issue to use mixed voltage standards on a single bank. As long as that particular I/O bank supported your I/O standard (Vccpd=2.5V and Vccio=1.8V)

    Regards,

    Matt

3 Replies

  • ShafiqY_Intel's avatar
    ShafiqY_Intel
    Icon for Frequent Contributor rankFrequent Contributor
    5 years ago

    Hi Zak,

    There is no issue to use mixed voltage standards on a single bank. As long as that particular I/O bank supported your I/O standard (Vccpd=2.5V and Vccio=1.8V)

    Regards,

    Matt

    • Zak's avatar
      Zak
      Icon for New Contributor rankNew Contributor
      5 years ago

      Hi Matt,

      I know that there is no issue to use mixed voltage standards on a single bank. What I don't understand is if I can do it with LVDS inputs, since the Vccio requirements in Table 5-9 of the Device Handbook for LVDS inputs is not so clear.

      For LVDS outputs the requirements are Vccpd=2.5V and Vccio=2.5V.

      For LVDS inputs the requirements are Vccpd=2.5V and Vccio=? Is it not relevant since only Vccpd is used for input LVDS buffers?

      Thank you

      • ShafiqY_Intel's avatar
        ShafiqY_Intel
        Icon for Frequent Contributor rankFrequent Contributor
        5 years ago

        Hi Zak,

        For LVDS inputs the requirements is Vccio=Vccpd

        For LVDS outputs the requirements is Vccio=2.5V

        And for Cyclone V, the value for Vccpd is 2.5V

        Regards,

        Matt