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Altera_Forum
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8 years ago

Cyclone 5 mismatch between VCCPD and VCCIO

We created a custom board that has 5CSEBA4U19 chip. The VCCPD pins for all banks have 3.3V but VCCIO is 2.5 on some banks. The datasheet clearly states that I must set VCCPD to 3.3V when VCCIO ...
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Altera_Forum
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8 years ago

Hi,

Device will operated in recommencement condition only.

Board may work or may face drive strength issues.

Check the table:14 in the linkhttps://www.altera.com/content/dam/altera-www/global/en_us/pdfs/literature/hb/cyclone-v/cv_51002.pdf

and check the Fig 2:https://www.altera.com/support/support-resources/operation-and-testing/power/pow-overview.html

1.You have set VCCPD to 3.3 Volt and VCCIO=2.5 Volt which will have direct relation with input and output voltages(Vil,Vih,Vol & Voh).

According to your setup VVPD supply will have different range of Vil,Vih,Vol & Voh values and VCCIO will have another ranges.

You may not able drive logic high when pin is output & logic low when input.

Now if output of level shifter is high, you can drive predriver input only if you have voltage greater than 2.2V (vihmin of predriver block). so driving wise there may be issues.

Best Regards,

Anand Raj Shankar

(This message was posted on behalf of Intel Corporation)