Forum Discussion

XWang134's avatar
XWang134
Icon for New Contributor rankNew Contributor
6 years ago

Arria 10 3V I/O connect to 3.3V device

I have a broad with an arria 10 FPGA (10AX066N2F40), using a 2.5V VCCIO for 3V I/O bank 2L, and bank 2L connects directly to a MCU supplied by a 3.3V power. It mentions that VIH max=3.3V when VCCIO=...
JonWay_altera's avatar
JonWay_altera
Icon for Frequent Contributor rankFrequent Contributor
6 years ago

Hi @XWang134​ Do you mean if the MCU change to 0V, VCCIO will also return to 2.5V?

It is better that the VCCIO do not exceed 2.65V as specified in datasheet. Table 3. Recommended Operating Conditions for Intel® Arria® 10 Devices

Also, as https://www.intel.com/content/dam/www/programmable/us/en/pdfs/literature/hb/arria-10/a10_handbook.pdf mentioned: Arria 10 devices do not have on-chip clamping diode.

Here is what you can try:

1) Use an external clamping diode. I would expect that 2.5V + Vclamp lets say is 0.6V = input clamped to 3.1V. See if the VCCIO is better.

and

2) Check your regulator circuitry. By right, regulator regulates your VCCIO, and shouldnt be stable at 2.7V.