Altera_Forum
Honored Contributor
Honored ContributorUnused bank - VCCPD, VCCIO and VREF pins
Hello everyone,
If I do not want to use a certain bank of the Cyclone V, do I have to power the VCCPD, VCCIO and VREF pins? Cheers, AdamForum Discussion
5 Replies
Altera_ForumHi,
I want to ask same question. I have Cyclone V device and don't want to use a bank. Should I power that bank?- Altera_Forum
The handbook (Table 10-2) says that the POR circuit does not monitor VCCIO but it does monitor VCCPD. From that I'm guessing you have to power both VCCIO and VCCPD in all banks. No problem not powering VREF for sure.
What is your motivation for not powering the bank? The power savings would be minuscule in an idle bank. - Altera_Forum
Hi Adam,
Generally we could refer to the CV pin connection guidelines (https://www.altera.com/content/dam/altera-www/global/en_us/pdfs/literature/dp/cyclone-v/pcg-01014.pdf) to see how to deal with the unused pins. In CV pin connection guidelines, it says unused Vref pin can be connected to VCCIO of its bank or GND. As for VCCIO and VCCPD, there is no mention about unused pin connection. Thus, I believe VCCIO and VCCPD should always be powered even the bank is unused. - Altera_Forum
Keep the power rail connected even if you are not using it. Not much power consumption. If for some reasons you cannot connect a rail to it, at least keep those POR monitored supplies connected.
- Altera_Forum
Yes, I agreed with nicejob comments. There is minimal power savings when powering down the VCCIO voltages. Here is the solution posted by Altera can be your references:
https://www.altera.com/support/support-resources/knowledge-base/solutions/rd12172008_333.html
