Forum Discussion
BrianSune_Froum
Contributor
ContributorCyclone 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...
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?
FvM
Super Contributor
Super ContributorHi,
I don't expect that this (apparently flawed, unclear transistor gate/source connection) principle schematic is helping to identify possible leakage paths between VCCPD and VCCIO node.
Not sure what you are trying to achieve, why has VCCIO 1.2 V supply high impedance in your design? Is there anything against applying a moderate pull-down resistor, e.g. 1k at VCCIO 1.2V rail?
Regards
Frank
