Simple Internal Rules of Thumb

Rules are given in order of priority.

• Consistency is key for clarity

• passives to power rails should be vertical

  • i.e. i2c pullups and decoupling capacitors

• schematics should follow a logical left to right flow

  • input on the left, output on the right

• higher electrical potential (voltage) rails should be above lower voltage rails

• signal passives should be horizontal.

  • i.e. shunt resistors

• Show Parameters for components

  • it should be obvious which parameter corresponds to which component based on proximity.

• minimize corners in schematic wires when possible

• components should be placed in the schematic near components they will be near in the layout when sensible

  • notably, decoupling capacitors should be placed in the schem near the IC they’re decoupling rather than say off on a random sheet. See Decoupling Capacitors for further detail.

• minimize length in schematic wires when sensible

• do not use excessive hierarchy

  • do not have a bunch of nested schematic sheets, it makes things confusing

Why We do this

• Standard

  • Makes reviews easier!

  • Improves human readability

• We dont want to nitpick

  • If you have a reason for doing something slightly different it’s fine

  • there are a lot of edge cases these simple guidelines dont cover so do what’s best and call it a day

    • as long as you did something for a reason then it’s chill, just don’t do things randomly

Learning

The best way to learn is to look at schematics and see what you think is reasonable. Check out past WARG designs and see how they style their schematics. Not everything we do is perfect, but a lot of it is decent and a great starting place!

External Lengthier Guides

• Schematic Style Guide

Further Info

• Electrical Terminology

• Net Naming Guidelines

• Schematic Four Point Nodes

• Importance of Schematic Grids

• Creating Common Components