Beginners' Layout Guide

  • use 4 layer instead of 2, SGGS stackup
  • you don’t need power planes/pours
  • bypass cap as close as possible to the power pin
  • you don’t need to length match most signals (Ethernet, FS USB): Edge is 200mm long
  • no ground cutouts under inductors or switching nodes
  • set fabrication rules, don’t trust the defaults
  • series termination close to the driving pin
  • every ground pad gets its own ground via, as close as possible to the pad
  • when switching layers, always place a return current ground via as close as possible to the signal via
  • inductor dot pin (start of winding, interior) goes to the switch node
  • use thermal relief on PTH pads
  • no thermal relief on vias
  • if at all possible, only put parts on one side