Forum Discussion

Altera_Forum's avatar
Altera_Forum
Icon for Honored Contributor rankHonored Contributor
15 years ago

Voltage range added on I/Os

the output voltage of MAX197(AD) is 5V,can it be added directly to IOs of EP2C8Q208?

thank you!

2 Replies

  • Altera_Forum's avatar
    Altera_Forum
    Icon for Honored Contributor rankHonored Contributor

    Digital inputs of MAX197 have a TTL specification and can be driven by a 3.3V supplied FPGA output, but data from MAX197 to FPGA need a level conversion. Because the data bus is birectional, either 5V tolerant bidirectional buffer (e.g. 74LVC245), a true level converting buffer, or at least series resistors and PCI clamp diodes at the FPGA should be used.