ACKNOWLEDGEMENT
First of all I would like to thank to my teachers who guided me whenever I faced problems during my training. In my six months industrial training it is a wonderful experie experience nce to be a part part of EUREKA EUREKA ELECTRO ELECTROSOF SOFT T PVT. PVT. LMTED LMTED where I have opportunity to work under brilliant minds. I owe my deep regards for the supporting and kind staff authorities who are helping me in my lean patches during this course. The knowle knowledge dge I am gainin gaining g throug throughou houtt my studie studiess have have the practi practical cal implem implementa entatio tion n during during this period. I am grateful to all the staff of EEAST EEAST and for their timely support and sharing of their experience with me. I would like to express my heartiest concern for for Ms. Baljot kaur for her able guidance and for her inspiring attitude, praiseworthy attitude and honest support. Not to forget the pain staking efforts of our college training and placement cell and specially my training and placement officer. Last but not the least least I would would expres expresss my utmost utmost regard regardss for the electro electronic nicss and commun communica icatio tion n department of my Institute.
COMPANY PROFILE
EUREKA ELECTROSOFT SOLUTIONS PVT. LTD (EESPL) ……..making IT happen Augmentation is a dream virtue of every performer – we at EESPL envisaged on a them themee for for prov provid idin ing g a new new epit epitom omee of IT solu soluti tion onss in the the embe embedd dded ed Tele Telecom com & Softwa Software re based based Produc Productt develo developme pment nt service services. s. Our edge edge right right from from the start start was creating a perceptible differentiation among the plethora of communized IT solutions .
EESPL - where progress is a winning winning habit Eureka ElectroSoft Solutions Pvt. Ltd. (EESPL) is primarily operating as a registered R & D lab for the development and conception of Advanced Automation related software and hardware solutions. Our expertise includes electronics and software bas based ed stan stand d alone alone solu soluti tion onss as well well as comb combin ined ed integ integrat rated ed solu soluti tion onss term termed ed as “Elect “Electros rosoft oft Soluti Solutions ons”. ”. At EES EESPL PL over over the years years we have have develo developed ped a core core competency to maximize the quality & innovation parameter while working on any task. Our proven values have made us as a prime leader in providing customized solutions.
It is our our stiff stiff endeavo endeavorr to amplif amplify y our clients viewpoints and to carve up their thoughts. This in turn is transformed into factual scenario working models with a
collection of prime technological aspects. All this is and much more in the shortest turnaround period.
EESPL – the background and essence of operations The year 2002 witnessed the birth of a visualization – which was to impart economy with a pinnacle swiftness of innovation in contemporary Industrial IT Solutions. There came EESPL and a new chapter of imparting excellence in IT techniques came into subsistence.
That was the foundation foundation and today the road voyaged by EESPL encompasses encompasses years of relianc reliance, e, accompl accomplish ishmen ments ts and above above all unlimi unlimited ted bonds bonds.. Bonds Bonds that that speak speak for themselves, relationships that reflect factual progress. Triumph at EESPL is defined as the never ending smile on our dear customer’s face. At EESPL we do not impart conception, we create endearing teams.
Indulging within minds, Imparting technologies Understanding the pulsation of a customer forms our principal challenge. Assurances that that mean mean resul results ts,, effo effort rtss that that capi capitu tulat latee adva advanc ncem emen entt and and outco outcome mess that that move move imaginings form the spirit of our day after day working. Timeliness is of chief value to us and and unde unders rsta tand ndin ing g the the mode modern rn day day race race for for time time,, we deli delive verr the the maxi maximu mum m in minimum and that too with precision. Our approach of operation also constitutes of a dedicated Registered Research and Development lab to make available the final deliverables with thread bare technologies. Our precedence is often devised on the scale of our customer’s desires. After carefully analyzing analyzing on the need based approach approach we craft a well planned set of operations – each fragment is build with an in depth focus on customer’s requirements.
CONTENTS
•
•
•
PCB designing
Types of PCB
Techniques used for PCB designing
Orcad design environment
Starting capture
Project manager
Session log
Layout
Design window
•
Power system design
•
Bibliography
PCB DESIGNING
PCB stands for “PRINTED CIRCUIT BOARD”. Printed circuit board (PCB) provides both the physical structure for mounting and holding the components as well as the electrical interconnection between the components. That means a PCB = PWB (printed wiring board) is the platform upon which electronic components such as integrated circuit chips and other components are mounted. A PCB consists of a non-conducting substrate substrate (typically fiber glass with epoxy as resin) upon which the conductive conductive pattern or circuitry is formed. Copper is the most prevalent conductor although nickel, silver and tin are also used in some cases. Types of PCB
PCB may be of different types:1) Sin Singlegle-si sid ded 2) Doub Double le-s -sid ided ed 3) Mult Multil ilay ayer er
Single Single sided PCBs: - As the name suggest in these designs the conductive pattern is
only at in one side. And also the size is large in these case but these are cheap. Double sided PCBs: - These are the PCBs on which the conductive pattern is in on
both sides. The size of board is small in this case but it is costlier than that of above. consists of alternating alternating layers of conducting conducting Multilayer PCBs: - In this case the board consists pattern pattern and insulating insulating material. material. The conductive conductive material is connected connected across the layers through plated through holes. The size of this PCB is smaller than that of double sided PCB but it is very costly. PCBs may also be either rigid, flexible, or the combination of two (rigid-flex). When the electronic components have been mounted on the PCB, the combination of PCB and components components is an electronic electronic assembly, assembly, also called PRINTED PRINTED CIRCUIT ASSEMBLY. ASSEMBLY. This assembly is the basic building block for all the electronic appliances such as television, computer and other goods.
FUNCTIONS OF PCB
Printed circuited boards are dielectric substrates with metallic circuitry formed on that. They are some times referred to as the base line in electronic packaging. Electronic packaging is fundamentally an inter connection technology and the PCB is the baseline building block of this technology.
TECHNIQUES USED FOR PCB DESIGNING
There mainly two techniques which are use for the PCB designs. 1. Hand Ta Taping 2. Comp Comput uter er Aide Aided d Des Desig ign n
1) PCBs using Hand Taping: o
PCB PCB desi design gn usin using g hand hand tapi taping ng is the the proc proces esss of tech techni nica call drawing.
o
In hand taping method layout should be prepared on grid paper.
o
In hand taping, components pads can be prepared by using black pads.
o
Routing of the board can be done by tapes with different widths.
Each layer (top, bottom) has to prepare separately.
DISADVANTAGS OF HAND-TAPING FOR PCB DESINING:
Each layer has to be designed sep We cannot generate NCD files for CNC drilling. Difficult to modify the design in the designing process or after designing.
2) PCB DESIGNING DESIGNING USING USING CAD
All the above difficulties can be removed by using CAB system. CAD system for PCB designing requires following: o
A computer system.
o
PCB design software like OrCad, CADSTAR, Protel, TANGO, Mentor etc.
o
A photo plotter for art work generation.
There are many enhanced features in electronics design automation tools which not possible in the hand taping. The main advantages are given below: o
Auto placement
o
Auto routing
o
After routing, optimization of tracks can be done.
o
Provides physical design reuse modules
o
Electrical rule check (ERC)
o
All the layers are generated from the same design by giving different options.
o
Bill of material can be generated which contains number of different components used.
o
We can draw conductors as an arc, semi-circular at different angles.
o
Design Rule Check
o
Advanced CAD systems have high speed analysis.
o
CAD system provides all NCD files and Gerber data files for photo plotting.
BASIC DESIGN STEPS IN CAD- SYSTEM
The following design steps are very common while designing a PCD in CAD: •
•
Entry the schematic diagram. Net list file creation.
•
Placement of components manually or automatically.
•
Routing of the board using manual routing tools or auto router
•
Design rule check physical and electrical.
•
Artwork generation.
OrCad Design Environment OrCad has a long history of providing individuals and teams with a complete set of technol technologi ogies es that that offer offer unprece unpreceden dented ted produc productiv tivity ity,, seamle seamless ss tool tool integr integrati ation, on, and exceptional value. New 10.5 release continues that tradition.Today's lower cost and yet highly highly sophis sophistic ticated ated electro electronic nic design design automa automatio tion n system systemss have have created created a unique unique challenge challenge to nearly every engineering engineering department. department. Therefore Therefore the use of EDA tools has become become increasingl increasingly y important important as product product lifecycles lifecycles have become shorter shorter and shorter. Modern electronic design automation (EDA) tools are beginning to support a more efficient and integrated approach to electronic.OrCad Capture® design entry is the most widely used schematic entry system in electronic design today for one simple reason: fast and universal design entry. Whether you're designing a new analog circuit, revising schematic diagram for an existing PCB, or designing a digital block diagram with an HDL module, OrCad Capture provides simple schematic commands you need to enter, modify and verify the design for PCB. OrCad Layout ® offers PCB designers and PCB design teams the power and flexibility to create and share PCB data and constraints across the design flow. OrCad Layout delivers all the capabilities to designers need from netlist to place and route, to final output. The ease-of use and intuitive capabilities of OrCad Layout
PCB DESIGN STEPS IN OrCad 9.1 Entry of Schematic Diagram
Schematic diagram provides the functional flow and the graphical representation of an electronic circuit. The entry of schematic diagram is the first step in PCB design using OrCad. A schematic diagram consists of:•
Electrical connections(nets)
•
Integrated circuits symbols
•
Discrete components symbols like resistors, capacitors etc.
•
Input / output connectors
•
Power and ground symbols
•
Buses
•
No connection symbols
•
Components reference names
•
Text
The Schematic Page Editor:
The schematic page editor is used to display and edit schematic pages. So that one can parts; wires; buses and draw graphics. The schematic page editor has a tool palette that we can use to draw and place everything we need to create a schematic page. One can print from within the schematic page editor, or from the project window.
Starting Capture
The OrCAD Release 9 installation process puts Capture in the \PROGRAM FILES\ORCAD\CAPTURE folder, and adds “OrCAD Release 9” to the Programs menu (available from the Start button).
To start Capture
From the Start menu, choose Programs. The Programs menu displays. From the OrCAD Release 9 menu item, choose Capture. The Capture session frame
Once we start Capture, we see the Capture session frame we do all your schematic design and processing within this window.The minimized Session Log icon in the lower left portion of the Capture session frame is the session log. The session log provides information about everything we have done in the current Capture session. Detailed information about this window—and the other windows in Capture.
The Capture work environment
In Capture, each design that we open is in a separate project manager window. If we need to work simultaneously with several designs, designs, we can open them all, and each will have its own project manager window. Depending on which type of window we have active(an active window is one whose title bar is highlighted), highlighted), certain buttons on the toolbar and certain items on the menus may be unavailable, since we perform tasks and use tools based upon the type of window that is active. Also, the menus and menu choices vary, depending on which type of window is active. The available menus and menu choices will also vary depending upon the type of project you are working with. It shows the windows we see in Capture: the project manager, the schematic page see in Capture: the project manager, the schematic page editor, the part editor, the text editor, and the session log. It also introduces we to the toolbar, tool palettes, and general Capture concepts such as selecting and editing objects, editing properties, and undoing and repeating actions.
The project manager we use the project manager to collect and organize all the resources we need for our project. These resources include schematic folders, schematic pages, part libraries, parts, VHDL files, and output reports such as bills of materials and netlists. A project doesn’t actually contain all the resources. It merely “points to” the various files that the project uses. For this reason, we don’t move or delete any files referenced by a project. If we do, the project won’t be able to find them. The project file is saved with an .OPJ file extension. It is an ASCII file, and can be viewed in any text editor.
Project manager folders
The project manager provides a
graphical display of a project’s resources by grouping them into appropriate folders. Design Resources folder is the design folder with the design’s schematic folders and schema schematic tic pages, pages, and a Design Design Cache Cache folder folder that shows shows all the parts used on the the sche schema mati ticc page pages. s. Any Any sche schema mati ticc fold folder erss or sche schema mati ticc page pagess that that we crea create te are are auto automa mati tica call lly y add added to the the desi design gn fold folder er (in (in Fig. Fig. the the desi desig gn fold folder er is named amed DESIGN3.DSN). we can also add other files or information using the Project command on the Edit menu The Library folder (in the Design Resources folder) shows the schematic part library files we’ve added to the project using the Project command on the Edit menu. The Outputs folder shows the output of Capture’s processing tools. Generally, these files includ includee bill bill of materi materials als report reportss and techn technolo ology gy-sp -speci ecific fic netlis netlists ts Captur Capturee adds adds the appropriate files to this folder as each is created. Each project may have only one design, but may have multiple libraries. The design may consist of any number of schematics or VHDL models, but it must have a single root module The root module is defined as the top level of the design. That is, all other modules in the design are referenced within the root module. Within the project manager, we can expand or collapse the structure we see by doubleclicking on a folder, or by clicking on the plus sign or minus sign to the left of a folder. A plus sign indicates that the folder has contents that are not currently visible; a minus sign indicates that the folder is open and its contents are visible, listed below the folder. It appears as a schematic folder with a slash on it in a design file, or as a page in a VHDL file. Each project we open has its own project manager window. we can move or copy folders or files between projects by dragging them from one project manager window to another (as well as to and from Windows Explorer). Explorer). To copy rather than move items, press and hold the C key while we drag them. If we close a project manager window, we close the project.
In the project manager’s File tab, double-clicking on a schematic folder expands it and displays icons for each schematic page within the schematic folder. Then, if we doubleclick on a schematic page icon, the schematic page opens in a schematic page editor. Or, if the page is already open, its window becomes active.
A design can consist of a single schematic page within a single schematic folder, or a
number of schematic pages within a number of schematic folders. A schematic folder“contains” folder“contains” schematic pages in a relationship similar to the relationship between a directory and the files it contains. Files are contained in a directory; schematic pages are contained in a schematic folder.
A schematic page provides a graphical description of the electrical connectivity of a design. It is made up of parts, wires, and other electrical symbols. symbols. A schematic page may also contain borders, title blocks, text, and graphics. Capture acts on any schematic folders or schematic pages we have selected within an active project manager window. For example, the Find and Browse commands on the project manager’s Edit menu, the Print command on the project manager’s File menu, and the various tools on the Tools menu, only apply to the selected schematic folder or page.
Project manager tabs—File and Hierarchy
The project manager provides two ways to display a project’s resources. If we choose the File tab, the project manager displays all the project’s folders, schematic folders, and schematic pages. These are displayed in a tree-like fashion. we can expand or collapse the tree by clicking the plus sign in front of the icon. When that branch of the tree is expanded, the plus sign change to a minus sign.If we choose the Hierarchy tab, the project manager displays the hierarchical relationship among the project’s schematic folders and schematic pages.
Single view
Versions of Capture prior to Release 9 used logical mode and physical mode to separate instance and occurrence information. Now, both instances and occurrences are contained in a single view. The project manager shows all occurrences in the Hierarchy tab. In versions of Capture prior to Release 9, it was necessary to switch modes before creating a netlist for use with OrCAD Layout. Now, the netlist tool provides an option to use either the instance properties or the occurrence properties for creating a netlist.
The schematic page editor
The schematic page editor is used to display and edit schematic pages. we can place parts, wires, buses, and draw graphics. The schematic schematic page editor has a tool palette that we can use to draw and place everything we need to create a schematic page. we can print from within the schematic page editor, or from the project manager window.
Schematic page editor
The part editor The part editor is used to create and edit parts.
From the View menu of the part editor you can choose either Part or Package. In Part view we can: •
Create and edit parts and symbols, then store them in new or existing libraries. libraries.
•
Create and edit power and ground symbols, off-page connector symbols, and title blocks.
•
Use the tool palette’s electrical tools to place pins on parts, and its drawing tools to draw parts and symbols.
•
Package view shows the entire package. A package is a physical part that contains more than one logical part. we can edit the properties of the entire package, such as part reference, prefix, part alias, and so on. we cannot edit individual parts in this view, but we can select individual parts to edit by doubleclicking on them.
•
The part editor is very similar to the symbol editor.
•
The main difference between the two is the symbol editor’s lack of Pin and Pin Array tool palette buttons.
The session log The session log lists the events that have occurred during the current Capture session, including messages resulting from using Capture’s tools. To display context-sensitive context-sensitive help for an error message, put the cursor in the error message line in the session log and press The ruler along the top appears in either inches or millimeters, depending depending on which measurement system (U.S. or Metric) is selected
in the Windows Control Panel. we can add tab settings to the ruler by clicking in the ruler bar, dragging the tabs to different positions, positions, or remove them by dragging them down into the session log window. our tab settings are saved and used each time we start Capture. we can search for information in the session log using the Find command on the Edit menu. We can also save the contents of the session session log to a file, which is useful when working with OrCAD’s technical support staff to solve technical problems. The default filename is SESSION.TXT.
To display the session log Click on the session log’s maximize button, or choose Session Log from the Window menu.
To minimize the session log Click the minimize button on the title bar.
To copy session log text to the Clipboard Select the session log window to make it active. Select the text and choose Copy from the Edit menu.
To print the session log Select the session log window to make it active. From the File menu, choose the Print command.
To use Find in the session log Select the session log window to make it active.
From the Edit menu, choose the Find command. The Find dialog box appears. Enter the word or words that we want to find. Click Find Next.
To save the session log to a text file
Select the session log window to make it active. From the File menu, choose the Save As command. The Save As dialog box appears. Enter a file name in the File name text box. By default, the session log is saved to SESSION.TXT SESSION.TXT in the current directory. If necessary, specify a new location for the file. Click Save. The session log text is saved to the file.
The toolbar
The toolbar is always docked on the top edge of the session frame the first time we open a project in a new session frame of Capture. The position of the tool palette is not saved. Capture’s toolbar is dockable(that is, we can select an area between buttons and drag the toolbar to a new location) and resizable, and displays tooltips tooltips for each tool. By choosing choosing a tool button, we can quickly perform a task. If a tool button is dimmed,we can’t perform that task in the current situation.
The part editor tool palette The first group of tools on the part editor tool palette are electrical tools, used to place pins and IEEE symbols. The second group of tools are drawing tools, used to create graphical objects without electrical connectivity connectivity
Starting a project A project file (.OPJ) stores pointers to a single design file(.DSN), and can also contain libraries, VHDL files, and output reports associated with the design file. A design file contains one or more schematic folders, in which there are one or more schematic pages. A design file also contains a design cache, which is like an embedded library- it contains a copy of all the parts and symbols used on the schematic pages. When a design is saved with the project file, information from the various Tools dialog boxes is also saved in the project file.
Creating new projects,designs, projects,designs, libraries we can create a new project, and then create new designs, libraries. libraries. To create a new project •
From the File menu, choose New, then choose Project. The New Project dialog box appears.
•
Type a name for our new project in the Name text box
•
Use the Browse button to select a new directory.
•
Select a project type in the Create a New Project Using group box, box, and click OK. Capture provides the following project types:
Analog or mixed signal circuit —select this type of project if we intend to use your
design with OrCAD PSpice. Follow the guidance of the Analog Mixed-Mode Project wizard to add the appropriate files to project. PC board— select select this type of project if we intend to use our design with OrCAD
Layout. Follow the guidance of the PCB Project Wizard to add the appropriate files . Programmable logic— select select this type of project if we intend to use our design with Or
CAD Express. Follow the guidance of the Programmable Logic Project Wizard to add the appropriate files to our project. select this type of project if none of the other project types apply. Using this Schematic— select option, Capture creates a basic project containing only the design file.
To create a new design From the File menu, choose New, then choose Design. • •
The design opens in a new PCB project manager and a new schematic page displays.
To create a new schematic page •
On the File tab of the project manager, select the schematic folder that requires a new schematic page.
•
Click the right mouse button and choose New Page from the pop-up menu. A new schematic page appears within the schematic folder we selected in step 1.
To create a new library •
From the File menu, choose New, then choose Library •
The library opens in the project manager and a Library Cache folder is added to the project manager, or the library opens in the existing open project manager and a library cache is added.
Opening existing projects, designs, and libraries we can open an existing project, design, library or VHDL file. Existing schematic pages can only be opened from within designs and libraries
To open an existing project
From the File menu, choose Open, then choose Project. The Open Project dialog box displays. Select a project (.OPJ) or type the name in the File name text box, then choose the Open button. The project opens in the project manager. To open an existing design
From the File menu, choose Open, then choose Design The Open Design dialog box displays. Select a design (.DSN) or type the name in the File name text box, then choose choose the Open button. The design opens in the project manager.
To open an existing schematic page
In the project manager, select the File tab and double-click the icon of a schematic folder; this Expands the folder and reveals the schematic pages it contains. Double-click on the icon of the schematic page we want to open. The schematic page opens in a schematic page editor window. To open an existing library
1 From the File menu, choose Open, Open, then choose dialog box displays.
Library. The Open Library
2 Select a library (.OLB) (.OLB) or type the name name in the File name text box, box, then choose the Open button.The button.The library opens in the project manager.
Working with files in a project Using the project manager, manager, we we can can add or delete project files. we can add any file to our our project, project, including including libraries and VHDL VHDL files. Files not in ASCII ASCII format, format, or a Capture generated format, may not appear as expected when opened in Capture. To add a file to project
1 In the project manager, select the folder to which we want to add a file. 2 From the Edit menu, choose Project. The Add File to Project Folder dialog box displays. 3 Select the file we want to add and choose the Open Open project.
button. The file is added to the
Or 1 Drag the file from the Windows Explorer into the
folder in the project manager.
To delete a file from a project
1 In the project manager, select the file we want to 2 Press the
D
delete. dele te.
key. The file is removed from the project proj ect..
Savingprojects,designs,and libra librarie riess
When the project manager window is active, we can save a new or existing project, design, or library. The Save command saves all open documents referenced by the project, as well as the project itself.
The Save As command command saves files depending depending on what we manager.
have selected selected in the project
- If one or more more designs designs or or libraries libraries are selected, selected, we are prompted prompted to save each file in turn. -If no top-level folders (Design Resources or Outputs) are selected, and items other than designs or libraries are selected, the Save As As command command is unavailable. -If no designs or libraries are selected in the project manager, you you are prompted to save the project. To save a new design or library With the design or library selected selec ted in the project choose Save. The Save As dialog box displays. •
•
manager manager,, from the File menu, menu,
Enter a name name for the design design or library in the File File name name location, then choose the Save button.
text box, specify a
The design or library is saved, and the project manager remains remains open. When When we close the project, Capture prompts we to save the project file. •
To save an existing project •
•
With the Design Resources or Output folder selected, menu. The project is saved, and remains open in the Capture
choose Save from the File
session session frame.
CLOSING A PROJECT To close a project
From the project manager’s File menu, choose Close Projec Project. t. When we close a project, a dialog box displays, asking if we want to save changes. To quit Capture
From the project manager’s File menu, choose Exit. Choose Yes to save the specific document Choose Yes All to save all documents in the proje pro ject ct.. Choose No to close the document without saving it. Choose No All to close all open documents documents without without saving them. Choose Cancel to abort closing the project. •
• • •
•
SETTING UP PROJECT P ROJECT Capture Capture provi provides des differe different nt levels levels of confi configura guration tion.. Using Using menu, we can:
command commandss on the Option Optionss
Customize Customize the working working environme environment nt specific to our system (using Preferences). Create Create default default settings settings for new designs designs (using (using Design Design Template). These settings stay sta y with the design design as design properties properties even if it is moved moved to another another system with different preferences. Overri Ov erride de settin settings gs in indivi individu dual al desig designs ns (usin (using g Desig Design n Properties) or individual schematic pages (using Schematic Page Properties). Regardl Regardless ess of which which Captur Capture e window window is active, active, the the Opti Op tion onss men menu u has has a Preferenc Preferences es comman command d and a Design Design Template Template command. command. In addition, the Options menu menu conta contain inss comma command ndss speci specific fic to to the the curre current nt acti active ve wind window ow.. For example, the project proje ct manager’s Options menu menu contains the Design Properties command, command, while the schem schemati atic c page page editor editor’s ’s Op Optio tions ns menu menu contai contains ns the schem schemati atics cs page page proper properties ties command. The settings settings in the Preferences Preferences dialog dialog box determin determine e how how Capture works on our system, and persist from one Capture Capture session session to the next because because they are stored in the Capture initial initializat ization ion (.INI (.INI)) file on our our system system.. If we pass projec projects ts to others, others, they won’t won’t inherit inher it our Preferences settings. This means we can set colors, grid display display options options,, pan and zoom zoom options options,, and so on on to our liking and be assured that our settings will remain, even if we work on a project created on another system. • •
•
The Design Template dialog box determines the default characteristics of all the projects created created on our system system.. Because a new project inherits characteristics from the current current Design Template Template settings, settings, it’s a good good idea to check the settings before we create a new project. Once we begin working working on a project, project, we can customize customize its particular particula r characteristics characteri stics by choosing choosing Design Design Proper Propertie tiess from from the the Opti Option onss menu menu wh when en we we are are in the the proj projec ectt manager or Schematic Schematic Page Properties Properties w when hen we are in the schematic page editor.
DEFINING SELECTION OPTIONS
we can specify whether whether objects are selected when the
selection border border intersects intersects them
or if the objects are selected only when they are completely completely enclosed in the area. area. we can also also change change the the maxi maximu mum m num number ber
of objects displayed at high resolution
while dragging, dragging, and set tool palette visibility visibility in both the schematic schematic page part and symbol editor.
selectio selection n
editor, editor, and the
Select tab of the Preferences dialog box To define selection options
From the Options menu, choose Preferences, then
choose the Select tab.
For the schematic page editor and the part editor, set
these options:
Specify whether to select objects objects that Area Select . Specify intersecting the selec selection tion border or
are inside and
only only objects objects that are are fully fully enclos enclosed ed by the
selection border. Maximum Maximum number number of objects to display at high
resolution resolution while
dragging . If we drag more objects then we specify here, we will see
rectangular placeholders placeholders for the objects as we
drag drag them. the m.
Show Palette . Select Select this this check check box to to make make the
visible; visible; deselect deselect it to make make the
tool
tool tool pale palett tte e
palette invisible. Cli Cl i ck OK OK..
Setting miscellaneous options we can can speci specify fy the the defaul defaultt fill, fill, line line style style and width width,, and
color for graphics graphics objects,
define the font used iin n the project manager manager and and session session log, log, render TrueType TrueType fonts fonts with with strok strokes es (for (for prin printin ting g and and plot plottin ting), g), and set wh whethe etherr to
enable auto recovery recovery for our
project and how often. In addition, addition, we can enable intertool intertool communicatio communication, n, which the method that Capture uses to to communicate communicate with
is
other other OrCAD OrCAD softwa software, re, such as
OrCAD Express, OrCAD PSpice, PSpice, and OrCAD Layout Layout .
Miscellaneous tab of the Preferences dialog box
To set miscellaneous options 1
From the Options menu, choose Preferences, then
choose the Miscellaneous tab.
2
For the schematic page editor and the part editor, set these options:
Fill Style . Select the the fill pattern pattern to be be used when when
drawing drawing rectangles rectangles,, ellipses, ellipses, and and
close shapes drawn with the polyline tool. Line Style and Width . Select the line style and
rectangles, ellipses.
widt width h us used ed for for lines, lines, pol polyl ylin ines es,,
Color . Select Select the color used for graphic object
(rectangles, ellipses, and closed
polylines).
Set the following options: Project Manager and Session Log .
Select a font for display text in the project manager and session log. If we select select this option, option, a standard standard Windows dialog box for font selection appears. Select a font, style, and size from the dialog box, then click OK. Text Rendering .
The text rendering rendering options options affect how text on a schematic page appears on your and how it it is printed or plotted plotted.. The
screen, screen,
Render Render TrueT TrueType ype fonts fonts with with strokes strokes option option
disp displa lays ys text text as a seri series es of line lines, s, conn connec ecte ted d to
resemb resemble le the outlin outlines es of the
corresponding TrueTy TrueType pe letters letters or numbers numbers they represent represent..
Enabling Enabling the Fill text
option causes the text outlines to be filled in. in.
Auto Recovery .
Select Select whethe whetherr to enable enable auto
recov recover ery y for for our our proj projec ectt and, and, if so, so, the the inte interv rval al
between saves. we can specify any interval
betwe between en five five min minut utes es and and 120 120 min minut utes es..
When When the the time time interval interval is up, up, any design design,, library, library, or VHD VHDL L
file in in your your project project that that
hasn’t hasn’t been been saved, saved, or has been modified modified since since the the last last save, save, is saved as a file (with an .ASP extension) in the the
WINDOWS/ WINDOWS/ TEMP/ TEMP/ AUTOSAVE AUTOSAVE directory.
When we close our project normally, normal ly, the
/ AUT AUTOSA OSAVE VE director directory y and temporar temporary y
file filess are deleted deleted.. In cases cases of power power outage outagess or syste system m
cras crashe hes, s, howe howeve ver, r, the the
temporary temporary files are saved. When we restart Capture, it loads the auto show showin ing g “Resto “Restored red” ” in their their title title
temporary
recovered recovered files,
bars. we must use the Save As comman command d and
provide a filename to have an auto recovered file
overwrite overwrite the original original file.
Auto Reference .
Select Sele ct whether to enable
automat automatic ic annotatin annotating g of reference reference designa designators tors
when parts
are placed.
S elect whether to enabl enable e intert intertoo ooll comm commun unica icatio tion n Intertool Communication Communication . Select (also known
ITC),
that
test and display design
informat information ion usin othe
OrCAD OrCAD software software (such as Layout, PSpice, and Express) in conjunction with Captur Capture e proce processes sses its tools tools faster faster wh when en
intertool intertool commu communicat nication ion is not selected. selected.
Capture. Clic Cl ick k
OK.
Setting text editor options Capture’s Capture ’s text editor options opti ons include automatic automat ic
high highlig light hting ing of VH VHDL DL keyw keyword ords, s,
commen comments, ts, or quoted quoted strings. We can also set the font, the tab spacing, and
enable or
disable the highlighting feature.
Text Editor tab of the Preferences dialog box
To set text editor options
From the Options menu, choose Preferences, then
choose the Text Editor tab.
Set these options: Select the color color to use to highl highligh ightt VH VHDL DL keywor keywords, ds, Syntax Syntax Highlighting Highlighting . Select comments, comments, and quote. quote.
change the font setting setting for the text text editor editor to values values Current Font Setting . Click Set to change other than those those displa dis playe yed. d.
Tab Spacing . Set the tab spacing for the text editor.
Check the the Highlight Highlight Keywords, Keywords, Comm Comments, ents, and those VHDL items
Quot Qu oted ed Stri String ngss optio option n to have have
highlighted highlighted in the text editor. The colors used to
these items are the ones set in the Syntax
highligh highlightt
Highlighting group box.
If we we want to reset the text editor options to the
Capture default values, click the Reset
button. Click OK. SETTING UP PROJECT TEMPLATES
The options that we define in the Design Template dialog
box are the default settings settings for
all new proje projects, cts, and for for schematic schematic pages you you add to an existing existing project. project. we can override some some of these options options for individual projects or
schematic schematic pages. pages. Some Some of of the the
things things we we can can define define in the Design Template dialog box are: Fonts . we can define define the fonts fonts for for schematic schematic page page
objects objects that contain contain text, text,
such as part references references and values values.. Title Block . we we can specify the text to appear in title
the the path path and filena filename me of the
block fields, as well well as
librar library y containi containing ng the title block block.. Th This is affects affects new
projects, as well as new schematic schematic pages in existing existing
projects. projec ts.
specif y whether inches inche s or Page Size . we can specify
milli millimet meters ers are used as the unit unit
of measure, measure, the the width and height of a schematic page, and the spacing between pins. Grid Reference . For horizontal and vertical border
grid referen references, ces, we can set
the the num numbe berr of of bor borde derr grid grid references references to d displ isplay ay in either either directio direction, n, wheth whether er the
grid
references are alphabetic or numeric, whether they increment or decrement across the schematic page, and how wide wide grid reference cells are. we can also make make the border, grid references, references, and title block visible visible or invisib invisible. le. This This affect affectss new projects, projects, as well well as as
new
schematic pages in existing projects. For hiera hierarch rchic ical al bloc blocks ks and and part part insta instanc nces es that that have have their their Hierarchy . For Primitive Primitive property property set set to Default, Default, we we
can specify if if we want Capture to treat each as
primitiv primitive e (cannot (cannot descend descend into attached schemat schematic ic folders) folders) or nonprim nonprimitiv itive e (can descend into attached schematic folders).
can specify specify whi which ch Captur Capture e SDT Compatibility . we can
properties properties map to to which which
OrCAD Schematic Design Tools (SDT) part fields when saving a project in SDT
forma format. t.
Defining title block information There are two types of title blocks: default and optional. •
we specify the information that goes into the default
title block in the Title Block tab
of the Design Design Templ Template ate dialog box. Capture places a default title block in the lower right corner corner of each schemat schematic ic page page (if (if a library library
and title block name name are specified), specified), and
places the information we enter enter in the text fields in the Title Title block. This information is also
Block Block tab into the title
used used in reports reports creat created ed by the the comman commands ds on the the Tools Tools
menu. This This affects new new projects, projects, as well as as new
schematic schematic pages in existing existing projects. projects.
we can set the default title title block block to be visible visible or invisible on an
existi existing ng schem schemati atic c
page by changing the setting in the Grid References References tab in the Schematic Schematic Page Properties Properties dialog box. •
we can place place any number of optional title blocks
anywhere anywhere on the schematic schematic page page
usin using g the the Tit Title le Bloc Block k comman command d on the the Place Place menu. menu. Option Optional al title title blocks blocks information that you define as property
values for the title block symbol. symbol.
display
Title Block tab of the Design Template dialog box
Capture provides default title block symbols symbols in the title block is shown shown
CAPSYM.OLB CAPSYM.OLB library. One One such
belo below w. Th The e tex text show shown n in curly curly brace bracess acts acts as prop proper erty ty text text
placeholders. placehol ders. we can specify the value by
double-clic double-clicking king on the text and supplying supplying
a value. we can control the visibility visibility by selecting or deselecting deselecting the in the Display Properties dialog box.
Title block
Visible check box
To choose a title block and define the text it contains
1 From the Options menu, choose Design Template,
then choose the Title Block tab.
2 In the Text group box, enter enter the information we want want
to appear in the title block.
3 In the Symbol Symbol group box, enter the path and filename title block.
of the library containing the
The Library Name text box can be left blank if you are using title block from the CAP CAPSYM SYM.OL .OLB B
librar library y and and CAPS CAPSYM YM.OL .OLB B has has not not been been moved moved to
a
different directory from where it was installed. If weare using a custom title title block, then put the
full full pat path h and and file file nam name for for
the library library in the Library Name text box. 4 Enter the exact name of the title block into the Title
Block Block Name Name text text box. box. Symb Symbol ol
names names are case sensitive sensitive and space sensitive. 5 Click OK.
Setting the schematic page size for new projects For new projects, we can can specify the the default unit unit of
measu measure, re, the the defau default lt width width and
height of schematic pages, and the spacing between pins. The value we enter in the to-Pin Spacing text box defines defines how how close together
Pin-
pins are placed in the part editor. It
also defines the grid spacing (the space between grid dots or grid lines)
Page Size tab of the Design Template dialog box
To set up the schematic page size 1
From the Options menu, choose Design Template,
then choose the Page Size tab.
2
In the Units area, select the default unit of measure for new projects. This setting only affects the schematic page editor, not not the part editor.
3
Select the default schematic page size for new projects.
For each schematic page
size (A, B, C, D, E, and Custom Custom if the unit of measure measure is Inches; or A4, A3, A2, A0, and and Custom Cust om if the the unit of measure meas ure is is
Millim Millimeter eters) s) you can specify specify the wid width th and
heig height ht.. Th The e values that you enter enter in the Width Width and and Height Height text dimens dimension ionss for each page page size. You You
A1,
boxes boxes becom become e the the
cannot cannot change these these dimension dimensionss for individ individual ual
schematic schematic pages, although although you can select a different different
page size, or choose to define a
custom size. 4
In the Pin-to-Pin Pin-to-Pin Spacing Spacing text box, box, specify specify the the default default
spacing spacing between between pins. pins. T The he
value value you you enter enter in this text box defines how close together pins are when you place a part on a schematic page. It also defines the grid spacing (the space between grid dots or grid lines). You cannot change this value for existing
projects projects or individual individual
schematic pages.
D e f in in i n g t h e g r i d r e f e r e n c e we set the border’ border’ss grid grid referenc references es to displ display ay either either
hori horizo zont ntal ally ly or vert vertic ical ally ly,,
alphabetically alphabetically or numerically, incrementally or decrementally across the schematic page, and the width of their cells. You can also make the border,
grid references, and title block
visible or invisible on the screen and on schematic pages you print. The settings new projects and new schematic pages in existing
projec proj ects. ts.
affect
Grid Reference tab of the Design Template dialog
To define the grid reference 1
From the Options menu, choose Design Template, then choose the Grid Reference tab.
2Specif Specify y
the num number ber of of border border grid grid refer referenc ences, es, whe whether ther
they are alphab alphabetic etic or numeric, numeric,
whether whether the grid references references incremen incrementt (Ascen (Ascending ding)) or or decrem decrement ent
(Descending) (Descending) across across
the schematic page, and how wide the grid reference cells are. 3For
the border, border, title block, block, and grid reference, reference, selects selects
Displ Displaye ayed d to have have the the item item displa display y on
screen screen or Printed Printed to have have the item item appear appear on schematic schematic pages
you print. print. .
LAYOUT
What is Layout? Layout is one part for the PCB Design in which we place as well well as route the components and set unit of measurements, grids, grids, and spacing in orcad. With With other softwares you also have to place and route the components in a similar way. For the placement and routing of the components we normally use Auto-placement and Auto-routing. Repetition of the steps for board design :•
At first, we have created a netlist from our schematic diagram by using capture.
•
Layout includes design rules in order to guide logical placement and routing.
That means, load the netlist into layout to create the board. At the same time you have to specify the board parameters. •
•
Specify board parameters:- Specify global setting for the board, including units of measurements, gride and spacing. In addition , you create board outline and define the layerstacks, padstacks, and vias. Place components:- Use the component tool in order to place manually the components which are fixed by the system designer on yhr board or otherwise Auto- placement.
Route the board:- Use different routing technologies to route the board and take advantage of push and shove, in which moves the tracks to make room for thr track you are currently routing as well as you can also auto route the board.
•
•
Provide finishing of the board:- layout supplies an ordered progression of commands on the Auto menu for finishing your design. These commands includes Design Rule Check, clean up design, Rename components, back Annotate, Run post processor, and create reports.
The Design Window: 36
The design window provides a graphical display of printed circuit board, it is a primary window you use when design your board. It also provides tools to facilitate the design process such as to update components and design rules violations. The design window appears when you open a new existing board.
The Library Manager
The Library Manager Window is used to view, edit and create footprints and footprints libraries. we can assign footprints to components in board. we can also modify and change footprints footprints pad stacks in the library manager. The library manager is split into two w indows one is library manager and second is footprint window.
To open the library manager
37
Choose the library manager toolbar button or from the file menu, choose the library manager. The session log
The session log lists all the events that have occurred related to the currently open board. If we are facing any problems during designing layout then we can see all the errors in the session log and verify our design errors. To open the session log: •
From the file menu, choose text editor appears like a notepad.
•
From the text editor’s file menu, choose open. The open dialog box appears.
The toolbar By choosing a tool in the toolbar, we can quickly perform the most frequent layout tasks. When we move the pointer over a toolbar button, the button’s name appears below the button.
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39
40
41
Method to create a board with Layout Plus: Ensure that net list with all footprints and necessary information has been created. Create a directory in which the schematic design, net list, and boar will co-exit and put the schematic design and net list. OrCad provides a directory for this purpose. From the layout session frame’s file menu, choose New. The load template file in the dialog box displayed.
Design window
42
Select the technology template (.TCH), then choose the open button and load the net list in other box.
Then apply the auto ECO.
If necessary, respond to link footprints to component dialog.
Draw the board outline by using the obstacle tool in the tool bar .
Setting board parameters: There is some parameter which should be set before placing the components on board. They are as follows:-
•
Set Datum
•
Create a board outline
•
Set units of measurements
•
Set system grid
•
Add mount holes
Creating of board outline: Board outline is the graphical representation of the size of the actual PCB board. So it is the main step in layout, to draw the board outline o utline of the actual size of PCB board. bo ard.
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Placement of components: Placement of components means that to place the components in designed box. A designer should follow the following steps before going for it:-
•
Optimize the board for component placement.
•
Load the placement strategy file.
•
Place components on the board.
•
Optimize placement using various placements
Components can be placed by using two techniques:1) Manual Manual placem placement ent of comp componen onents ts 2) Auto Auto place placemen mentt of compone components nts
Choose the components tool bar button. From the pop up men, choose the queue for placement. The compone components nts select selection ion criter criteria ia dialog dialog box appears appears.. Enter Enter the refere reference nce design designato atorr of the components that we want to place in the appropriate text box, and click ok. Drag the components to desired location, place it there.
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Conductor Routing in Layout:After After placing all the components components the other other main step is to route the board board from the electrica electricall connections between the components. One may route board manually or automatically by auto router. 100% auto routing can be achieved only when components are placed in the order of functional flow of electronic circuit. The main routing tool available in OrCad is as flow:•
Add/edit route mode
•
Edit segment mode
•
Shove track mode
•
Auto path route mode
Design Rule Check:In manual designs every thing was checked as a possible source of error. Components sizes, hole sizes, conductor widths and clearance, land-to-hole-ratio, board areas to be free of components, clearance to the edges, positional accuracy and of course electrical interconnections had tad to be personally reviewed with a great deal of care. After completing the design of printed circuit board with the help of an EDA-Tool, a designer has again to verify the PCB in order to find out errors. Such type of verificati verifications/de ons/design sign rule check contains beside the general general verificati verifications ons commonly commonly two types:•
Physical verification
•
Electrical verification
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Post processing:Post processing can be done once the design is completed in all aspects. The common way is still a process to generate GERBER data and NCD files which can be used for photo plotting plotting and for steps of CNC manufacturing and PCB- drilling.
POWER SYSTEM DESIGN First part of electronics ckts. is power. The main power supply is in AC but mostly electronic ckts. work with DC. So a system is required to convert ac to dc and these sources should able to produce stable supplies. Power supplies may be used in. may be of different types such as regulated, unregulated, smps etc.
Unregulated power supplies These are the power supplies in which the out put is not constant. That it is varies with input voltage, load, and also effected by the environment conditions such as temperature, etc. so these are the variable supplies. Commonly these supplies are not employed as there efficiency is very less. The unregulated power can be obtained using rectifying circuit after AC supply.
Regulated power supplies These are the power supplies in which the output voltage is constant, i.e. the out put voltage is independent of the input voltage, load and other external conditions. So to obtain the regulated voltage using different regulators. The regulator voltage is mainly the DC voltage, it may AC to
or DC to DC volt voltag age. e. A bett better er approa approach ch to powe powerr supp supply ly desig design n is to use use enoug enough h
capacitance to reduce ripple to low level, then use an active feedback circuit to eliminate the remaining ripple and dependence of output voltage on input, load and environment conditions.
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These active devices are known as Regulators. These regulators can be used to produce negative and positive voltage of required value.
The voltage regulators are of three types:1) Consta Constant nt positi positive ve voltag voltagee regulat regulators ors 2) Consta Constant nt negativ negativee voltage voltage regulat regulators ors 3) Variab Variable le voltag voltagee regu regulat lators ors
Constant positive voltage regulators:regulators:These are the regulators which are able to produce positive and constant voltage. Some of them are given below:S. no.
Name of regulator
Output voltage
1
LM 7805
5v
2
LM 7810
10v
3
LM 7812
12v
4
LM 7815
15v
These regulators are used according to the required voltage need.
Constant negative voltage regulators:These are also the constant output voltage regulator but there output is negative in polarity. These regulators are also employed according to voltage requirements. Some of them are given below with there outputs:S. no
Name of regulator
Output voltage
1
LM7905
-5v
2
LM7910
-10v
3
LM7912
-12v
4
LM7915
-15v
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Variable voltage regulators:regulators:These are the regulator whose output voltage can be varied according to the desired need. These regulators again of two types i.e.:•
Positive
•
Negative
The output of these regulators can be varied by varying the resistance of the variable resistance which is connected to the adjustable pin the regulators. So these are the most commonly used regulators in the electronic industry as wide range of stable voltage can be obtained from single chip chip by varyin varying g the resist resistanc ancee connect connected ed to the adjust adjustabl ablee pin of the regula regulator tors. s. The most most commonly variable regulators are:-
•
LM317 (it is positive regulator)
•
LM 337(it is negative regulator)
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BIBLIOGRAPHY
•
www.google.com
•
www.eeast.biz
•
www.electrosoft.biz
•
www.techera.co.in
•
Study material by eeast
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