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PCB Artist

Library Creation Tutorial

Copyright Notice

Copyright  WestDev Ltd. 2000- PCB Artist is a Trademark of Advanced Circuits. All rights reserved. E&OE

Copyright in the whole and every part of this software and manual belongs to WestDev Ltd. and may not be used, sold, transferred, copied or reproduced in whole or in part in any manner or in any media to any person, without the prior written consent of WestDev Ltd. If you use this manual you do so at your own risk and on the understanding that neither WestDev Ltd. nor associated companies shall be liable for any loss or damage of any kind.

WestDev Ltd. does not warrant that the software package will function properly in every hardware software environment.

Although WestDev Ltd. has tested the software and reviewed the documentation, WestDev Ltd. makes no warranty or representation, either express or implied, with respect to this software or documentation, their quality, performance, merchantability, or fitness for a particular purpose. This software and documentation are licensed 'as is', and you the licensee, by making use thereof, are assuming the entire risk as to their quality and performance.

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Number One Systems & PCB Artist are trademarks of Westdev Ltd and Advanced Circuits respectively.

Issue date: 07/06/07 iss 1

Advanced Circuits Inc. 21101 East 32nd Parkway Aurora, CO 80011 Toll free: 800-979-4PCB (4722) 1-303-576- Fax: 1-888-224-

Chapter 1. Library Creation

Introduction

PCB Artist is supplied with a set of libraries. These libraries can be used, modified and added to as required. You can mix and match new and existing library items together to create your own set of unique libraries.

The next few chapters concentrate on getting you started with creating your own libraries. After the last chapter on designing Components, there is more detail about how to use the Library Manager.

Understanding PCB Artist Libraries

PCB Artist libraries are easy to understand and use once your grasp the basic concepts. The libraries are made up of three individual libraries. There is a Component library made-up of elements from the Schematic Symbol library and the PCB Symbol (footprint) library.

Schematic Symbol library

Symbols are often called ‘Gates’. These have generic names like: NAND, Buffer, OPAMP, Res, Cap.

PCB Symbol library These have generic names like: DIP14, SOIC14, QFP

These are used in component libraries to produce >

Component libraries These normally use the manufacturers proper component names like: SN SN74LS PIC18C CA

Only the names from this library is used in both Schematic design and PCB layout.

In a working example, this is how it might look:

+ + =

SN7400 Component

This is stored in the Component library as an SN7400 to be used in our designs.

4x gates 1x PCB symbol

Component

Question: Can I create a Schematic symbol in PCB Artist and then select it

for use in the Schematic design without creating a PCB symbol?

You can create a new Schematic symbol and store it in the Schematic symbol library. But before you can use it in a design you have to create a Component for the symbol and store this in the Component library for use in your designs. Typically, this is how power and ground symbols would be defined for example.

Why is there this added step of creating a Component - why can’t I just

use the symbol immediately?

Working this way, any Schematic Symbols you produce are stored with an appropriate name in the Schematic symbol library. It can then be reused multiple times to create different components using the manufacturer’s component name. Most components you produce will have the complete Schematic symbol and PCB symbol.

Is this the same for PCB symbols? Can I create a PCB symbol without a

Schematic symbol?

This is exactly the same for PCB symbols as with Schematic symbols. Before you can use your new PCB symbol in a design you have to produce a component even though this component may not have a Schematic symbol associated with it. A PCB only symbol could be added to the design as a drawing blank or a test-pad probe point for example.

Once a PCB only or Schematic only component has been created, the missing opposite symbol type can be added to make it available to both design editors.

On the following pages is a tutorial that goes through the steps of creating Schematic symbols, PCB symbols and a component to tie them together.

Note : Standards for symbols vary from company to company. The tutorial is presented only as a means to understand the process of design and management and how to use the tools available.

Schematic and PCB Symbol Libraries

Two types of symbol libraries exist, those for Schematic symbols with the extension .ssl, and those for PCB symbols with the extension .psl. There is no limit how many symbols may be kept in a given library.

Component Libraries

Component libraries can be identified with the file extension .cml. Each component in a library is aware of the symbol name and library name of its constituent symbols. The components can contain several Schematic symbol ‘gates’ in each component, and a number of PCB footprints, each with its own symbol. For example, a component might have assigned to it 3x NAND gates and a power gate for use in the Schematic design, a DIL and an SMD footprint for use in PCB. The diagram below shows how the Component will access both the Schematic symbol library and the PCB symbol library as required in the relevant design editor.

'COMPONENT'

Name: 74LS

Schematic Symbol PCB Symbol

Schematic Symbol PCB Symbol

Schematic Symbol Library PCB Symbol Library (.SSL) (.PSL)

Component Library (.CML)

Reference: NAND2 Reference: DIP

Schematic Editor PCB Editor

Packages.txt (PackageType)

SM QFP etc.

DIL

Program

Libraries

Chapter 2. Creating Schematic Symbols

Getting Started

 To open the library manager

From the File toolbar, select the Libraries icon (shortcut Ctrl+L ).

 To open the symbol editor

From the Library Manager dialog, select the Schematic Symbols tab.

For this tutorial, we will create a new library for each symbol/component type. You could of course, add your new symbols to an existing library.

The Symbol Editor will take a set of default design settings, such as Styles, Colours, Grids, Units etc. These are taken from a selected Technology file. Once you become familiar with PCB Artist, you can customize these files using your own selections. If you click on the Tech Files button on this dialog, you will see how to choose this Technology file.

For now we will leave the defaults set to the ones supplied in the standard technology file.

We will create a new library in which to save the new symbol into. Click the New Lib tab.

In the New Library Name: box, type in the name Tutorial. This will be the name of your new library. Click OK to save this file name and exit the dialog.

The new Tutorial library is selected and is ready to have new symbols saved into it.

You need to create a new Schematic symbol so open the Symbol Editor using the New Item button.

The Symbol Editor opens. You will notice this looks very similar to the Schematic design editor used in the design tutorial. It is similar in its use and its interaction, the way in which items move and feel.

For this tutorial exercise, we are going to create an op-amp component. The component will contain two symbols, both different. It will use a op-amp gate plus a power gate, we will do this to demonstrate using multiple gates for one component.

You will create the op-amp gate only, the power gate (PWR) already exists in the supplied libraries. We will create this gate:

In order to get the triangle shape, you will need to take the editing mode out of Orthogonal and switch it into Free hand editing. To do this, click once to add a corner, 500 mil down ( grid points) from the start point and then right click to display the shortcut menu.

From the menu, select Segment Mode> and Free.

Now you can move the ‘floating’ second segment right 500 mil and up 250 mil to give you the point on the triangle. Because the grid is set to 50 mil steps you will be able to snap to 250 mils exactly.

Your shape should look like the picture below.

 To create an arc

This example doesn’t require an arc but if yours does in future, they are easy to create.

To add an arc, select a shape segment and right click. In the example below we have add an additional ‘box’ shape to demonstrate this on.

From the shortcut menu choose Arc> and then Angle 180. The segment becomes an arc.

The resulting arc looks like this:

If your arc is the wrong way (faces inwards no out), right click on the arc shape again and choose Arc> from the shortcut menu and Flip Arc. This will swap it the other way round.

 Adding pins

Pins need to be added to the Symbol to give PCB Artist ‘real’ electrical points on which to make connections. This gives PCB Artist its unique true electrical connectivity at all times.

On the Schematic Symbol toolbar, select Add Pad.

A pin will be available on the end of your cursor shown in the highlight color.

Position each pin on the end of the lines so that it looks like the example below. As each pin is positioned, the next one in the sequence is available on the end of your cursor.

You will see that these are auto-numbered as you proceed. After the last pin has been added, click the < Esc > key to cancel.

These pins must be sequential but the numbering sequence on the Symbol doesn’t matter, they are there for reference only. They must also be unique and with no gaps in the sequence.

Click the < A > key to position the symbol to fit the window.

 Information on the pins

Each Pin contains three pieces of information:

• the big cross marking the shape and location of the pin
• the Pin Number ( 1, 2, 3 etc. )
• the pin name position marker, N1, N2, N3 etc. which marks the location of the pin name when used on the Component in the design

The Pin name position marker ( N3) will only be populated once the Component is used in the Schematic design, until then you only see the name position marker. This

You may also see the symbol origin ‘ S’ character on Pin 1 if this pin was the first item to be added to the symbol (before the symbol shape).

The Pin Number is the automatically numbered. This can represent the actual terminal number if required but can be renumbered in the Component definition. The number is shown in the position it will appear in when used in the design. This can be moved in the Symbol editor but cannot be moved once placed in the design.

Tip: When adding pins, if you have moved the sequence number and the location or alignment of the pad name text, if you wish to use this on subsequent terminals, select it first and then select Add Pad. This will take the style of the selected terminal and add the next one in exactly the same way.

 Moving the symbol origin

The Symbol origin is the Symbol’s reference point used when moving it in the Schematic design (the small ‘ S ’ marker). For consistency we always try and place this in the same relative location, usually on Pin 1 of the symbol.

The symbol origin would have been added with the first design item. In our example, this was the symbol shape but it could have been the first pin added.

Select the origin on the symbol.

To do this, select the N3 pin name position marker and from the shortcut menu choose Properties , the following dialog is displayed:

You can change the text alignment that will be used once the symbol is placed in the design and if a pin name has been used, you can opt to align it Left or Right, that is the direction it will read from.

For our example, select the Right alignment and click OK on the dialog.

The symbol will update to reflect this change. The pin name direction is now left most of the pin maker indicating it will be justified from right to left.

 Adding the reference origin

Without a Reference Origin , the component name (U1, IC1 etc.) used in the Schematic design will automatically be placed on the Symbol Origin. By adding a specific Reference Origin you can position the Component name where you like.

By default, the PCB Artist libraries have the Reference Origin placed at the bottom right side of the Symbol shape.

To add the Reference Origin, select Reference Origin from the Add menu.

Place the ‘ R ’ marker on the Symbol.

When the Symbol is used with the component in the design, the Reference Origin is also used for positioning the Component Name, Package Name and PCB Symbol Name if these items are selected as displayed.

You are now ready to save the symbol into the library.

 Saving the symbol

From the File menu, select Save.

The Save dialog opens.

Choose the Tutorial.ssl library and give the symbol the name OPAMP , click OK.