S2.2 Non-functional variations in part number should be replaced with wildcard
Manufacturer Part Numbers (MPN) often include variations that are non-functional in terms of schematic entry and PCB layout.
Examples of parameters considered non-functional:
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Temperature rating of the component
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Packaging information (e.g. reel, tray, tape)
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RoHS / PbFree information
Examples of parameters considered functional are those that affect the schematic or layout of the part:
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Electrical variations - these indicate important different characteristics (e.g. different supply voltages)
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Package options - these indicate different footprints and/or pinouts
To capture every possible combination of part variation would require a large number of derived symbols and is to be avoided.
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Where an MPN has options for such non-functional variations, these portions of the MPN should be replaced with the wildcard character (lowercase
x
).-
If these non-functional parts of the MPN are at the end of the symbol name then the wildcard should be omitted.
-
-
Functional variations should be captured in the symbol name.
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If there’s only one functional variation of the part, the wildcard does not need to be applied
-
Example:
TPS3430
has only one variant:TPS3430WDRCR
. So the name should beTPS3430WDRC
, rather thanTPS3430xDRC
.
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