Creating Common Components

  • This document is a quick summary of Schematic Symbol and Footprint Guidelines to catch some common pitfalls

  • Follow the patterns

    • whatever’s done in our libraries most commonly is how we want it done always

    • people add some random stuff because we dont have a formal review proccess, but a vast majority of stuff that’s in there is just correct so try to blend in.

      • There are of course components that do not comply with thw atandards in the library. Feel free to upsate them when u are hsing them in your project.

  • Capacitors and Resistors commonly already exist in the library.

    • Do not add duplicates to the library. Check if what you want exists already by searching for the part number.

    • You’re welcome to delete duplicates. Keep the ones used in most places and delete the ones used in just one place.

  • common symbols and footprints must be used

    • do not clone these

    • do not edit these

    • there may be multiple in the library because people accidentally clone the generic ones. Simply used the “where used” feature and use the ones that are used in most places. the accidentally cloned ones are used on just one or maybe a couple components.

    • you’re welcome to delete duplicates as long as you move all the components over to the common ones first.

    • using different or random symbols and footprints for 0603s and other common packages results in boards that look terrible because every component that’s the same size has a different footprint. it’s really easier if you just use the common stuff and call it a day. the common stuff has correct layers and everything so it’s really easy!!

  • Name

  • Description

    • Follow the digikey format.

      • Some components have incorrect digikey descriptions in digikey, just follow the normal format.

      • this improves searhability

      • if ur confused, look at all the other caps/res in the library with this common description

      • The standard is well explained in Schematic Symbol and Footprint Guidelines as well …

    • do not use the trash random descriptions it gives

    • do not include extra info in the description

  • Parameters

    • do not use the random imported trash parameters. do not add extra parameters, it’s annoying to scroll through the useless trash.

    • For res and caps you must add the following and only the following parameters:

      • Capacitors

        • Voltage

          • i.e.: 50V, 100V, 16V

        • Temperature Coefficient

        • Capacitance

        • Package

      • Resistors (Good Example: AC0603FR-1310KL):

        • Tolerance

        • Resistance

          • i.e. 100k, 1M, 1m, 1k, 4.7k, 100

        • Power

        • Package

    • order doesn’t matter.

    • If the parameters do not show up in the schematic:

      • do not modify or clone the generic symbol

      • do confirm the above parameters are present in the component and if not then specify them

      • do go in your schematic and show the correct parameters

  • Other symbols/footprints

    • ICs should use the yellow square symbol

    • connector symbols should use the blue outline. see the other connectors and follow.

  • Yep that’s it.

    • you’d think it’s not that hard, but trust me i spend a ridiculous amount of time correcting the libraries because this is too difficult.