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BrianSune_Froum's avatar
BrianSune_Froum
Icon for Contributor rankContributor
5 months ago
Solved

Cyclone V custom board VCCIO puzzling behavior

Dear Intel and all, I am working on Cyclone V soc 5CSEBA5U19C8N. There is a very puzzling VCCIO behavior. According to "Cyclone® V Device Family Pin Connection Guidelines PCG-01014-3.2". Any 3...
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  • BrianSune_Froum's avatar
    BrianSune_Froum
    5 months ago

    There are new measured data.

    If I attached a simple 10k resistor to the 1.2V rail. it will drop back to normal 1.2 range.
    But the loaded /w 10k is still measuring 40mV higher than unloaded DCDC w/o the FPGA chip.
    So there are some leakage current inside the diode path? from VCCPD to VCCIO?

Farabi's avatar
Farabi
Icon for Regular Contributor rankRegular Contributor
3 months ago

Hello,


I have filed investigation request to engineering: 15018404392

This will take some time but engineering will take a look into this.


regards,

Farabi


BrianSune_Froum's avatar
BrianSune_Froum
Icon for Contributor rankContributor
3 months ago

@Farabi

This will help to check how much leakage and possible hazard.

BTW the compile settings make unused IO to output still introduce such problem.

The previous responses are included as much experiment data as possible.