ni multism 10 tutorial
TRANSCRIPT
Written By Stan Komsky
1 2
Table of Contents
2 Introduction
3 Creating a new Project with Cadence 4 Creating a new Project with Multisim 5 Placing Parts with Cadence 6 Placing Parts with Multisim
8 Adding a Library with Cadence
9 Connecting Parts with Cadence 10 Connecting Parts with Multisim
11 Editing Placed Parts with Cadence 12 Editing Placed Parts with Multisim
13 AC Simulation with Cadence 14 AC Simulation with Multisim
15 DC Voltage Analysis with Cadence 16 DC Voltage Analysis with Multisim
17 Error Analysis with Cadence 19 Error Analysis with Multisim
21 Plotting with Cadence 22 Plotting with Multisim
23 Cadence Troubleshooting 25 Multisim Troubleshooting
27 Works Cited
Introduction
The purpose of this manual is to describe the basic functions of
Cadence and Multisim. Simulating a circuit on a computer before
implementing it can help validate your design and catch potentially costly
errors ahead of time.
Multisim is an advanced circuit simulation program created by The
National Instruments Electronic Workbench Group. It provides a variety of
tools for users to create schematics of circuits, and simulate these
schematics. It is created to be very user friendly for both students and
advanced engineering users.
The Cadence OrCAD application provides a universal circuit design
and simulation platform. It can import and export schematics to almost any
other circuit design application causing it to be the most widely used
schematic design entry by the engineering industry. It also makes it easy to
make changes to large circuits by using a spreadsheet editor.
This manual will demonstrate the abilities of both programs from
designing a circuit to simulating an AC and DC analysis.
3 4
Creating a new Project with Cadence
1. Open Design Entry CIS using your desktop or start menu (usually
located in Applications\Cadence SPB 15.7\ Design Entry CIS).
2. If the Cadence Product choice menu opens, select the third option
labeled “Allegro PCB Design CIS XL.”
3. Select File ‐> New ‐> Project… to open the “New Project” menu
shown below.
4. Select “Analog or Mixed A/D” and enter a project name.
5. Click Browse to select a location to store your project.
6. Select “Create a blank project” if the “Create a PSpice Project” menu comes up.
Creating a new Project with Multisim
1. Open Multisim 10.0 using your desktop or start menu (usually
located in Applications\National Instruments\Circuit Design Suite
10.0\ Multisim 10.0).
2. The application will start allowing you to start your project.
Figure 2. Create PSpice Project Dialog.
Figure 1. Cadence New Project Menu.
5 6
Placing Parts with Cadence
1. Select Place‐>Part and the “Place Part” Dialog will appear.
2. Select all the libraries by clicking and dragging the mouse, or by
selecting one of the libraries and hitting Ctrl + A.
3. Find the component you would like to add in the “Part List” dialog
and click OK to add it. The following are some example components
you can add:
Part Name Picture Part/Library Name in Part List
Resistor
R/ANALOG
Capacitor
C/ANALOG
Inductor
L/ANALOG
Voltage Source
VAC/SOURCE
Current Source
IAC/SOURCE
Placing Parts with Multisim
1. Select Place ‐> Component and locate the component you wish to
place.
2. The “Select a Component” dialog should appear as shown on the
next page.
Here’s a tip: You can also hit Ctrl + W to open the “Select a Component” Dialog.
Note: If there are no libraries in the “Libraries” section of the dialog, follow the instructions in the “Adding a Library” located on page 8 before continuing.
7 8
3. Select the component you wish to add, edit the component settings
to your specifications, and click Ok.
4. Click on your schematic in the location you wish to add your
component, and the component will be added at that location.
5. A new “Select a Component” Dialog will appear. If you do not wish
to add another component, click Close to close this dialog.
Adding a Library with Cadence
1. Before being able to place parts, you must add the part library.
2. Select Place‐>Part and an empty “Place Part” dialog will appear.
3. Click Add Library… and browse to
“C:\Appl\Cadence\SPB_15.7\tools\capture\library\pspice\” or the
equivalent directory if your machine is using a different directory
structure.
4. Use your mouse or press Ctrl + A to select all the libraries shown
below.
5. Click Open to add these libraries.
Figure 3. Multisim Select a Component Denu.
Figure 4. Browse File Dialog for Adding Libraries.
9 10
Connecting Parts with Cadence
1. Go to Place ‐> Wire or select the place wire tool in the right side
menu as shown below.
2. Position your mouse on the small box at the end location of one of
the first connecting component. Your mouse point should turn into
a crosshair.
3. Click inside the box and drag it over to the small box at the end
location of one of the second connecting component.
4. Note that the path that your cursor follows will be followed with the
connecting wire.
5. You can change the location of the wires by clicking and dragging
after you are done connecting the components.
Connecting Parts with Multisim
1. Select the end of the first connecting component. Your cursor
should become a black dot when you are over a valid selection.
2. Click on it and drag it over to the end location of the second
connecting component. Your cursor should become a black dot and
the end of the component should become red when you are over a
valid selection as shown in the diagram below.
3. Note that the path that your cursor follows will be followed with the
connecting wire.
4. You can change the location of the wires by clicking and dragging
after you are done connecting the components.
Figure 5. Cadence Wire Tool.
11 12
Editing Placed Parts with Cadence
1. Select the part or parts that you would like to edit. They should
change to a pink color and have a dotted box around them.
2. Select Edit ‐> Properties or press Ctrl + E to open the “Property
Editor” dialog shown below.
3. You will see a list of circuit components you have selected and the
properties that you can edit.
4. You can change the name by editing the “Part Reference” column
and change the part value by editing the “Value” column.
5. Once you have finished making changes, click Apply. An Undo
Warnings” dialog will appear, click Yes to apply your changes.
6. To delete the component, simply select the component and press Delete.
Editing Placed Parts with Multisim
1. Double click on the part you would like to change. A dialog will appear
with properties you can change as shown below.
2. To change the part’s name, click on the Label tab.
3. Click OK to produce your changes.
4. To delete the component, simply select the component and press
Delete.
Note: When you delete a component, any wires previously connected to that component will still remain.
Figure 6. Cadence Property Editor Dialog.
Here’s a tip: You can make quick changes to a single parts by double clicking the value you would like to change on the schematic. Then change the value and press OK.
Figure 7. Multisim Property Editor Dialog.
13 14
AC Simulation with Cadence
1. Select PSpice ‐> Markers ‐> Voltage Level and place the Voltage Level
Marker on the part or parts of your circuit that you would like to
analyze.
2. To run the simulation, you must first create a simulation profile. Do
so by selecting PSpice ‐> New Simulation Profile.
3. A “New Simulation” dialog will appear. Enter a name for your
simulation and click Create.
4. On the “Analysis Type:” drop down menu, select “AC Sweep/Noise”
as shown below.
5. Enter the Start and Stop frequencies. These will be the X‐axis of your
graph, and your circuit will be analyzed between these frequencies. 6. Enter the Points/Decade. This is the amount of data samples that
will be displayed on the graph. Click OK. 7. Select PSpice ‐> Run or press F11 to run the simulation.
8. See the Plotting with Cadence section on page 21 for instructions on
how to add traces to your simulation.
AC Simulation with Multisim
1. Select Simulate ‐> Analysis ‐> AC Analysis… to open the “AC Analysis”
dialog shown below.
2. Enter the Start and Stop frequencies. These will be the X‐axis of your
graph, and your circuit will be analyzed between these frequencies. 3. Select the Output tab and add the proper variables to output. For
more information on doing this, see the Plotting with Cadence
section on page 21. 4. Click Simulate to display your simulation.
Figure 8. Cadence Simulation Settings Dialog.
Figure 9. Multisim AC Analysis Dialog.
15 16
DC Voltage Analysis with Cadence
1. To run the simulation, you must first create a simulation profile. Do
so by selecting PSpice ‐> New Simulation Profile.
2. A “New Simulation” dialog will appear. Enter a name for your
simulation and click Create.
3. A “Simulation Settings” dialog will appear. Click OK. 4. Select PSpice ‐> Run or press F11 to run the simulation. 5. Your schematic will now show the DC value at each node as shown
below.
DC Voltage Analysis with Multisim
1. Select Simulate ‐> Analysis ‐> DC Operating Point… to open the “DC
Operating Point Analysis” dialog shown below.
2. Select the variables you wish to analyze from the left “Variable and
Circuit” box and click Add to add them to the right “Selected
Variables for Analyze” box.
3. Click Simulate to show the analysis results. A “Grapher View” dialog
will appear showing the nodes and their corresponding voltage
levels.
Figure 11. DC Operating Point Dialog.
Figure 10. DC Voltage Analysis with Cadence Results.
17 18
Error Analysis with Cadence
1. Duplicate your original circuit by selecting the circuit and using the
Copy and Paste commands in the Edit menu. You will need both
circuits to run the error analysis.
2. Add a Capacitor and Resistor in parallel to your circuit to serve as
the oscilloscope for error analysis as shown bellow.
3. Select PSpice ‐> New Simulation Profile. A “New Simulation” dialog
will appear. Enter a name for your simulation and click Create.
4. On the “Analysis Type:” drop down menu, select “AC Sweep/Noise.”
5. Enter the Start and Stop frequencies and the Points/Decade. Click
OK. 6. Select PSpice ‐> Run or press F11 to run the simulation. 7. An “Allegro AMS Simulator” dialog should appear. Select Simulation ‐
> Trace ‐> Add Trace or press the Insert key. 8. Using the “Add Traces” dialog, create a formula to calculate the
percent error using as shown on the next page.
9. Click OK to add the trace to the graph. The graph will show the
percentage error due to AC Voltmeter loading as shown in the
example below.
Figure 12. Oscilloscope Addition on Right for Error Analysis.
Figure 13. Add Traces Dialog for Error Analysis.
Here’s a tip: You can measure percentage error by using the formula: 100*(V’ – V)/ V where V is the voltage prior to connection to the oscilloscope and V” is the voltage afterwards.
Figure 14. Example of Error Analysis Output in Cadence.
19 20
Error Analysis with Multisim
1. Duplicate your original circuit by selecting the circuit and using the
Copy and Paste commands in the Edit menu. You will need both
circuits to run the error analysis.
2. Add a Capacitor and Resistor in parallel to your circuit to serve as
the oscilloscope for error analysis.
3. Select Simulate ‐> Analysis ‐> AC Analysis… to open the “AC Analysis”
dialog and enter the Start and Stop frequencies. 4. Select the Output tab and click Add Expression to open the “Analysis
Expression” dialog as shown below.
5. Enter an expression for percentage error calculation and select OK. 6. Press Simulate to display your simulation. The graph will show
percentage error as shown below.
Figure 16. Example of Error Analysis Output in Multisim.
Figure 15. Multisim Analysis Expression Dialog.
21 22
Plotting With Cadence
1. When in the “Allegro AMS Simulator” dialog, select Simulation ‐>
Trace ‐> Add Trace or press the Insert key. 2. Using the “Add Traces” dialog, select the trace you would like to add
and click OK to add them to your graph. 3. To graph a formula, select the output variables from the left “Simple
Output Variables” menu and add mathematical expressions from
the right “Functions or Macros” menu. Then click OK to add it to
your graph. 4. To delete all traces, select Trace ‐> Delete all Traces or press Ctrl +
Delete.
Plotting With Multisim
1. When in the “AC Analysis” dialog, select the variables you would like
to plot and click “Add” as shown below.
2. Click Simulate to display the graph. 3. Select Edit ‐> Properties to bring up the “Graph Properties” dialog. 4. Select the Left Axis, Right Axis, Bottom Axis, or Top Axis tab to
change the scale, range, or title of the specific axis. 5. Select the General tab to change the title or grid properties.
Figure 17. Multisim AC Analysis Dialog.
23 24
Cadence Troubleshooting
Building the Circuit
I receive a yellow warning symbol when trying to connecting a wire
to my component.
1. Cadence has detected that making this connection might create an
error in your circuit. 2. You can proceed in making the connection, but take note of the
warning as it might cause problems in the future during simulation.
Simulating the Circuit
My Cadence Application does not have a PSpice menu for circuit
simulation.
1. You have opened the wrong Cadence application. Select File ‐> Save
to save your file. Select File ‐> Exit to close the window. 2. Open Design Entry CIS using your desktop or start menu (usually
located in Applications\Cadence SPB 15.7\ Design Entry CIS).
3. If the Cadence Product choice menu opens, select the third option
labeled “Allegro PCB Design CIS XL.”
I am receiving errors in the format of “ERROR ‐‐ Node N00023 is
floating” when trying to run my simulation.
1. Your ground is not properly connected. 2. If you do not already have a ground in your circuit, select Place ‐>
Ground to display the “Place Ground” dialog.
3. Select the ground component you would like to add and click OK. 4. Place the component in the proper location and select PSpice ‐> Run
or press F11 to run the simulation again.
I am receiving errors in the format of “ERROR ‐‐ Less than 2
connections at node M_UN0001” when trying to run my simulation.
1. One of your circuit components does not have a wire connected
from each side.
2. Select Place ‐> Wire and place the wire accordingly. For more
information on placing wires, refer to “Connecting Parts with
Cadence” on page 9.
My Simulation ran successfully but the graph is empty.
1. You must add traces to display on your graph. 2. Select Simulation ‐> Trace ‐> Add Trace or press the Insert key.
Using the “Add Traces” dialog, select the trace you would like to add
and click OK to add it to your graph.
Error Analysis
I receive an “Invalid Expression” error when creating my formula.
1. You have a syntax error in your error expression. Select OK and
change the expression to fix this error.
25 26
Multisim Troubleshooting
Simulating the Circuit
After running the AC Analysis and adding the proper output, a blank
graph appears.
1. There is most likely a problem with your circuit. Make sure all wires
are connected properly and run the analysis again.
When running a new AC Analysis, my old AC Analysis still appears in
the tabs. How do I delete it?
1. Select the tab with the unwanted analysis. 2. Press Ctrl + X to delete it.
DC Voltage Analysis
All of my outputted variables are 0 after running the analysis.
1. You most likely have an AC voltage source rather than a DC Voltage
source. 2. Select Place ‐> Component and locate the DC voltage source. Place it
onto your schematic and remove the AC voltage source.
Error Analysis
After entering the error percentage formula as the output, the graph
is still blank.
1. You most likely have a syntax error in your error expression.
3. Select Simulate ‐> Analysis ‐> AC Analysis… and select the Output tab
and change the expression to fix this error.
27 28
Works Cited
“flexible_printed_circuits_boards_photo1.” No date. Online Image. Starflex
Flexible Circuit Board Manufacturer. 16 October 2007.
<http://starflex.com/images/flexible_printed_circuits_boards_photo1.
gif>.
“General Warning Symbol.” No date. Online Image.
Welcome Information for the University of Bath. 16 October 2007.
<http://www.bath.ac.uk/internal/bio‐
sci/Images/haz%20general%20warning.gif
haz general warning.gif>.
"Lightbulb." No date. Online image. Vermont Guardian | For The
Independent Mind. 16 October 2007.
<http://www.vermontguardian.com/images/local/2006/
Lightbulb.jpg>.