FAQ: Floating Power Pins on Processors

Document created by jobo23 Employee on Aug 11, 2014Last modified by ColinJ on Aug 12, 2014
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Q: What sort of problems can I expect if I do not power one of the power domains that the processor datasheet requires be powered (even if I don’t need it in my design)?


A: The reason the datasheet indicates that all power domains must be powered even when the supported operation is unneeded by the application is because that is the way the device is designed.  If any domain is not properly connected, then ADI cannot guarantee the operation of the device, whether the concern is with functional operation, timing specifications, reliability, etc.  In short, if the datasheet indicates that a supply must be connected, then leaving it floating or otherwise improperly connecting it is not the intended operation of the processor, and this problem must be rectified in the design.