Library Conventions | KiCad EDA

Version 3.0.41

Library maintainer rules & guidelines

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:

  • Temperature rating of the component

  • Packaging information (e.g. reel, tray, tape)

  • RoHS / PbFree information

Examples of parameters considered functional are those that affect the schematic or layout of the part:

  • Electrical variations - these indicate important different characteristics (e.g. different supply voltages)

  • 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.

  1. Where an MPN has options for such non-functional variations, these portions of the MPN should be replaced with the wildcard character (lowercase x).

    1. If these non-functional parts of the MPN are at the end of the symbol name then the wildcard should be omitted.

  2. Functional variations should be captured in the symbol name.

  3. If there’s only one functional variation of the part, the wildcard does not need to be applied

    1. Example: TPS3430 has only one variant: TPS3430WDRCR. So the name should be TPS3430WDRC, rather than TPS3430xDRC.