PSPICE Tutorial

The following is a brief introduction to PSPICE.

1. Starting PSPICE

• To run PSPICE select Start ® Programs ® OrCAD Release 9 ® Capture.

• File ® New ® Project.

• Choose “Analog or Mixed-signal Circuit Wizard”

• Type in the name of the new project and specify the saving location(your W: drive) and click ‘OK’.

• Then you will be prompted to select the library ® select none and click finish.

• Open your new folder ® open SCHEMATIC1 ® open PAGE1.

2. Drawing the circuit in Fig. 2, Project #1

• Placing parts

Select Place ® Part (Or just click the “Place a Part” palette)

To retrieve r (resistor), c (capacitor), and l (inductor): select analog in the libraries and type in r, c, and l in the part name box respectively.

To retrieve vpulse : select source in the libraries and type in vpulse in the part name box.

To rotate a part, select the part and type r.

To flip a part, select the part and type h (horizontal) or v (vertical).

• Setting the part parameters

Double click on the resistance or capacitor, and the corresponding value of a resistance or a capacitance can be changed.

Double click on the pulse voltage source. Set the following parameters for the source:

V1 = -5 (the minimum voltage of the pulse)

V2 = 5 (the maximum voltage of the pulse)

TD = 0 (the delay from time zero of the first rising edge)

TR = 0 (rise time)

TF = 0 (fall time)

PW = (pulse width) equal to or greater than 5 times of t

• Wiring the components

Use shift-w to get the wiring tool and wire the circuit. (select wire in the palette)

• Grounding the circuit

select Place ® Ground (or just select ground in the palette).

Select source in the libraries and select “0”

3. Placing Markers

From the pull down menu, select PSpice ® select Markers ® select Voltage Level. Use this marker to calculate the voltage at the node between the two resistors Ra and Rb with respect to ground.

From the pull-down menu, select PSpice ® select Markers ® select Voltage Differential. Use the two markers to calculate the voltage across Ra. Click on the upper node of Ra, then on the lower node of Ra. You’ll see + and - signs in the markers, which indicate the reference polarity of the voltage.

4. Selecting the type of analysis

After all the steps mentioned above are done, you should select PSpice ® New Simulation Profile.

Select Time Domain (Transient) in the analysis type

Set the following parameters:

Maximum step size = 1/1000 of Run to time

Run to time = twice the pulse width

5. Simulating the circuit using PSPICE

Click on the pull-down menu PSpice. Select Run.

Or, you can simply press play button in the tool box.

6. Analyzing the results

This series of options is performed on the OrCAD Pspice A/D output window, which should show the desired trace at this point.

• Using the cursors

Click on the pull-down menu Trace. Select Cursor ® Display. You will then be given access to two cursors. One of the cursors is controlled by the left mouse button and one is controlled by the right mouse button. A small window labeled Probe cursor gives the values at each of the cursors as well as the difference between them.

• Marking a specific voltage level

Click on the pull-down menu Plot. Select Label ® Mark. This will label the specific point on the graph which is pointed to by the cursor that was last moved.

• Adding a plot

Click on the pull-down menu Plot. Select Add Plot to Window. Another axis will be added, although at this time there will be no traces on it. Any number of plots can be added, but using much more than two can make the printout be too crowded.

• Adding a trace

A trace can be added to the plot which is currently selected. A specific plot is selected simply by clicking anywhere on it. The selected plot is indicated by a SEL>> on its left side.

Click on the pull-down menu Trace. Select Add… Then you can enter any expression containing any currents or voltages on the schematic. This trace will then be added to the plot.

• Deleting a trace

First of all, the trace must be selected. This is done by clicking on the name of the trace. Then click on the pull-down menu edit. Select Delete.