1 Introduction to PSpice Lab 12 Let us start: What is SPICE? • SPICE stands for Simulation Package with Integrated Circuit Emphasis • SPICE is as close to a universally available package for doing numerical network analysis as one can find3 Getting PSpice • On the handout, is the procedure to access PSpice on ASU’s computers • You can download Pspice from http://class.fulton.asu.edu/eee202lab/PSPICE/ps9_1.zip • Those who have 64bit system can try installing using VM player (Virtual Machine for XP mode). http://www.howtogeek.com/howto/11060/create-an-xp-mode-for-windows7-home-versions-and-vista/ • First install VM player. Then install windows XP in VM player. Then install the PSPICE.4 Accessing SPICE Today • Turn on the computer. • The password is your ‘ASU RITE ID and Your own Password • Click on “Start”, then pull out “Programs”, then pull out “PSpice Student” and then click on the entry “Schematics”.5 Drawing Circuits • Use the “Edit” and “Draw” pulldown menus to draw a circuit in the schematics area6 Placing components • Go to the DRAW menu and click on “Get new part”. You can also get a part using control-G • If you know the PSpice name of the component you want, you can type it into this text box:7 Placing Components (contd.) • Click Place & Close and place about a half dozen resistors down by moving the mouse and clicking on the left mouse button • When done, click the right mouse button or you will keep placing resistors8 Manipulating Components • One Click on various resistors and move them around. • Click on a resistor and try out the “Rotate” entry of the “Edit” pulldown menu. Edit>Rotate Or CTRL>R9 Manipulating Components (contd.) • Click on a resistor and use the “Attributes…” entry of the “Edit” pulldown menu or double click the resistor itself – Change the following attributes: “VALUE,” to 5k and “PKGREF” to “Resistor1.” – Edit – Attributes10 Manipulating Components (contd.) • Names and values of the resistance can also be changed by double clicking on the displayed name and value • To delete a specific resistance (select the resistor with one click to turn it into red color) and press the “Delete” key on your keyboard.11 Other Components • PSpice includes various other circuit components such as: – Inductors (L) and capacitors (C) – Draw – Get New Part12 Sources • Most circuits in PSpice require a source of some kind. The most common sources used are Vdc, Idc, Vsin and Vpulse – Note that the current source Idc shows the flow of direction of the electrons, which is the opposite of current13 More sources • There are other sources such as Vac and Iac, but we seldom use them • Vsin is preferred to Vac because different frequencies can be set in Vsin – If you see any “ghosting” press ctrl+L on your keyboard to refresh the drawing area14 Basic circuits • Build a voltage divider in Pspice (GND) • Step 1: Place the components as shown • Edit>Attributes Draw>Get New Part>r>Place and Close • File>Save – To fit the components within the window, in PSpice, press ctrl+N on your keyboard.15 Wiring components • Step 2: Wire the components together – Select “Wire” from the Draw menu, or by clicking the button shown below or by pressing ctrl+w on your keyboard. – Draw – Wire or16 Connecting the components • To wire the components click and release the left mouse button at the start point. Move the pointer to the end point, and click and release again. This will wire two components together. Make sure your circuit looks like this:17 Common error • If your circuit looks like this: (GND) You have shorted out resistance R1. That is why you see the big dots on either side of the resistance and the wire running through it. (shown here in red). • Rectify it by deleting the wire running through the resistance R1.18 Simulation parameters • Set the value of the DC voltage source to 5 volts. • Click on the Analysis menu, and click on “Simulate.” Alternatively you can click on the button shown below or press F11 on your keyboard. Analysis>Simulate or19 Simulation results • You probably got an error as shown below: • If you see the “Node floating” error, you have not placed a ground in the circuit – Every circuit in PSpice MUST have a ground20 Grounds • There are two kinds of grounds in PSpice - Analog ground (agnd or gnd_analog in PSpice) and digital ground (egnd or gnd_earth in PSpice) • Left shows • Analog GND • Right shows • Digital Earth GND21 • Connect an analog ground to the circuit as shown and simulate your circuit as described earlier File>Save • Draw • Get New Part • Analog GND • Enlarge Circuit • Control >“N” Simulating Circuits on P-Spice22 Simulation Result • You should see something similar: (F11) – In the lower left corner, you can see a message saying “Simulation complete,” but there are no meaningful results displayed23 Displaying Results • Go back to your schematic (circuit) and from the Analysis menu, enable voltage and current displays. You can also click the buttons shown below: Analysis>Display>Enable or24 Interpreting results • Your circuit should now look as follows: – Selecting a voltage display shows the node with which it is associated – Selecting a current display shows the direction of the current25 FYI: Netlists • When you simulate your circuit, the internal software automatically generates something called a netlist that drives the actual number crunching – The Netlist describes your circuit textually – You can also create the Netlist without simulating your circuit by clicking on the “Create Netlist” option under the Analysis menu • In the Analysis menu, click on “Examine Netlist”26 FYI: Understanding the netlist • Below is a sample netlist for the circuit you built previously • If you look carefully, there are four columns. – The first column denotes the circuit component. – The second and third columns specify the nodes between which the component is connected. – The last column provides the value of the component27 FYI: Examine Your Netlist • For this circuit, the Netlist is easy to deduce. You can figure out which point on the circuit is denoted by nodes $N_0001, $N_0002 and 0. • However, for a more complex circuit, deducing the