Download AC simulation

AC simulation and Bode Plots – 320L
Build the circuit shown. Below the circuit is a list of the parts that were used and the libraries
that they belong to. It is important that you pay attention to which library you get the parts from.
If you are running the simulation at home using the student version the libraries will be different.
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The parameter Vac should be set to one.
Vcc
Vcc
R3
V2
R2
94.5K
Q1
C1
8\Vdc
4K
Vout
Vin
V1
0
100u
0Vdc
1Vac
TRAN =
Q2N2222
R4
R1
28.3K
1k
0
Note that nodes which have the same name are connected
Part
Part name
R
Q2N2222
Vdc
Library if you are at
school
ANALOG
BIPOLAR
SOURCE
Library if you are using the
student version at home
ANALOG
EVAL
SOURCE
resistor
BJT
DC voltage
source
capacitor
C
ANALOG
ANALOG
You can paste Pspice schematics into Word and Power point documents as well as other Pspice
documents. This is done with standard cut and paste commands.
To include the diagram in a document.
 Select the circuit
 Hit Ctrl-C (to copy to the clip board)
 Hit Ctrl-V to paste the circuit in the destination document
AC simulations can be used to generate Bode plots.
To perform an AC simulation
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From the main menu: Pspice->New Simulation (or Edit Simulation)
If you have typed new simulation: Enter a name for your simulation and hit <create>
You will see the menu below
Select AC Sweep/Noise as an analysis type
Hit <OK>
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You will see the window below
Enter starting and ending frequencies. IMPORTANT: the start frequency must not be
zero
To simulate: from the main menu: Pspice->Run
A Blank window will appear
To plot the amplitude of the waveform from the main menu select: Trace-> Add Trace
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The window shown below will appear. On the left are all the waveforms that are
available to plot. On the right are the functions that can be performed on the waveforms.
For our simulation we name the output Vout so we select V(Vout). If we had forgotten to
name the node we could access the same waveform V(Q1:c) the collector voltage of
transistor Q1. Currents can also be plotted. IB(Q1) is the base current flowing into
transistor Q1.
Hit <OK> to plot
To plot decibels select the function DB()
To plot phase select function P()
To plot input impedance plot: 1/IB(Q1)
To determine precise values from a simulation use cursors
 From the main menu select: Trace->Cursor->Display
 There are two cursers cursor A1 is affiliated with the left mouse key and cursor A2 is
affiliated with the right mouse key
 Pressing you left our right mouse key down you can slide the cursor crosshair along a
waveform
 The x and y data values at the position of the crosshair are displayed in the probe cursor
window
Click with left mouse to
affiliate this trace with the
left mouse cursor
To include a printout of the simulation
 From the main menu: Window->Copy to clipboard
 This plot is copied to the clipboard and can be pasted into a document using ctrl-V