Forum Discussion

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

cyclone IV I/O standard

Hi, I am using ep4ce30f29c6 (fbga780pin) with aproximately all IO in use. because of the need to use on chip termination, I use 3-volt as vccio. my main worry is that other parts in my design are ...
Altera_Forum's avatar
Altera_Forum
Icon for Honored Contributor rankHonored Contributor
14 years ago

Clamp diodes are silicon diodes with respective forward voltage. Exact data can be e.g. derived from IBIS files. With 0.3 V forward voltage, diode current will be low. I think however, that reasonable source side impedance matching of fast digital signals to the FPGA can obviate the need for clamping diodes.