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Altera_Forum's avatar
Altera_Forum
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12 years ago

Driver output impedance in Arria II GX for 3.3V LVCMOS / LVTTL I/O standard

Hello,

I understand that ARRIA II GX does NOT support output serie resistor OCT (with or without calibration) for 3.3V I/O banks.

Nevertheless, I have to adapt the impedance of the line but I couldn't find anywhere the min/max values of the driver output impedance and pick the correct value for the external serie resistor, anyone can help?

Thank you in advance.

1 Reply

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

    LVTTL has programmable drive strength which can be used to adjust the output impedance. There's no data sheet specification, but you can derive the expectable impedance range from the device ibis files.