Working models

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Index

• Working models
• Index
• Projects
• KiCad
  • Introduction
  • KiCad design flow
    • Creating the project
    • In eschema
    • In PCBnew
    • Other points
    • Layout layers
  • Design standards for the boards

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Projects

1. Series voltage regulator with feedback

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KiCad

Introduction

KiCad is used for all schematic and board design. First, each board has a separate project. KiCad projects have 4 types of files

• .pro
  • Stores project related information
• .lib
  • Libraries
• .sch
  • Schematic file
  • Opened using Eeschema
• .kicad_pcb
  • PCB layout file
  • Opened using PCBnew
• .net
  • Netlist file
• .gbr
  • Gerber files
  • Files used to define layers for fabrication
  • Opened using gerbview

Software that are part of KiCad

• Eeschema
  • Schematic editor and viewer
  • File extension : .sch
• PCBnew
  • Layout editor and viewer
  • File extension : .kicad_pcb
• Gerbview
  • Viewer for gerber files
  • File extension : .grbjob

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KiCad design flow

Creating the project

1. Create a project using File -> New -> Project.

In eschema

1. Click on the .sch file to open schematic in eeschema
2. Draw the layout
   • Add components using Place symbol on the right pane or shortcut A
   • Connect them using wires (Right pane : Place wire, shortcut W)
   • Place labels (Right pane : Place net label, Place global label)
   • Add text and stuff if you need it
3. Run Annotate schematic symbols on the top.
4. Perform DRC using Perform design rules check on the top.
5. Assign footprints to the symbols we have added using Assign PCB footprints to schematic symbols in the top.
6. Generate netlist using generate netlist button on the top.
7. Open PCBnew using run PCBnew to layout printed circuit board

In PCBnew

1. Run Update PCB from schematic to import the required footprints from the previous step
2. Arrange the components
   • Move using M
   • Add filled zones using Add filled zones in the right pane
   • Add wires using Route tracks in the right pane
     • Choose required layer in layers tab in right pane
     • If the layers tab is not visible, check show/hide layers manager toolbar
   • Right click filled zones and fill to generate gaps
3. Add text and lines and stuff for layers
4. Define board outline using polygons or lines on the Edge.cuts layer

Other points

• You can navigate easily between PCBnew and eeschema using buttons on the top
• Everytime you make a change in the schematic, it needs to be updated in the PCB.
  • Run Update PCB from schematic in PCBnew when this is needed
  • Change options as required
  • No need to generate netlist everytime

Layout layers

• F.Cu : Front copper
• B.Cu : Back copper
• F.Silks : Front silkscreen
• B.Silks : Back silkscreen
• Edge.cuts : Edges of the PCB

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Design standards for the boards

• Height must be 78mm
• Length maximum 155mm
• Use connectors for 2.54mm