I've got a TCMT1102 Vishay optocoupler. Its a 4-pin SMD part but there is no standard package type associated on the datasheet - i.e SOP, SSOP, TSSOP etc. Vishay has a footprint document that describes this footprint as a "SOP-4 miniflat" according to the dimensions. Based on the footprint doc I assumed its a SOP-4. But when looking at the IPC-7351 standard, section 9 there is no description for a "SOP-4." The lowest SOP pin count is SOP-8. And when referencing this package classifications document there is no description for a SOP-4, SSOP-4, or TSOP-4.

Additionally, the linked CAD Model for the TCMT1102 Digikey page is not in alignment with the datasheets dimensions.

Is SOP-4 a non-standard footprint? Where can I get this footprint?

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  • \$\begingroup\$ You should use your EDA software and make the footprint. This is fundamental and almost any substantial new PCB design will require at least a few (often more than a few) new footprints and schematic symbols to be created. \$\endgroup\$ Aug 2 '20 at 20:56
  • \$\begingroup\$ I was trying to avoid making the footprint if possible. And wanting to know if this is a standard IPC footprint or not. I can make it if needed, was hoping for a shortcut. \$\endgroup\$
    – Tim51
    Aug 2 '20 at 21:01

Many IC manufacturers use non-standard footprints - or make up their own.

Whether or not SOP-4, or any package for that mater, is a multi-manufacturer standard package is somewhat irrelevant. You should always follow the manufacturers datasheet and recommended footprint, even for more standard packages.

As to where to get the footprint, you either need to make it yourself for whichever tool you use (for something this simple, you could probably duplicate and modify an existing package), or find a CAD footprint from the manufacturer or tools such as UltraLibrarian.

If you find a CAD footprint from a secondary source such as vendor (e.g. Digikey), always double check that it matches the parts datasheet. If there are discrepancies, trust the parts datasheet.


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