Download Frequency_response_of_OpAmp

Experiment #1: DC, AC, and Frequency Response of an Op Amp Circuit
Pre Lab:
1. Simulate an inverting amplifier circuit using a LM 324 op amp.
a. The closed loop voltage gain (Av = vo/vi) should be designed to be -10.
b. Chose resistor values for R1 and R2 between 500 -20 kfrom the list of 5%
nominal resistor values.
c. The positive and negative voltage supplies, V+ and V-, should be set to 5 V and 5V, respectively.
d. The input voltage source should be a part called Vsin. Double click on this part
and set the DC offset voltage, VOFF, to 0V; the amplitude of the sinusoidal
voltage source, VAPML, to 1 V, and the frequency of the voltage source, FREQ,
to 1 kHz (which is equal to 1000 Hz).
e. Put two voltage markers into the circuit as shown.
2. Run the following simulations:
a. DC Sweep
i. Go to ANALYSIS/SETUP or click on the
button.
ii. Double click on the box labeled DC Sweep. Note: Never unclick the Bias
Point Detail box.
iii. Type the input voltage source label in the box next to the word NAME.
Note that this would be Vi in the drawing above, but this will not be the
name of the input voltage source in your PSpice drawing. Use the name
(should be V and then a number after it – V3 for example). The start
value should be 0V and the end value should be 1V. Select a reasonable
increment to obtain a smooth curve.
iv. Click OK on the DC Sweep window and then OK on the SETUP window.
v. Go to ANALYSIS/SIMULATE or click on the yellow button
to begin
the simulation. Another window should open and a plot of the output
voltage versus the input voltage should appear.
vi. Print a copy of the graph.
b. AC Sweep
i. Double click on your input voltage source. Select AC and set the value to
1V. Save the attribute and then click OK.
ii. Go to ANALYSIS/SETUP or click on the
button.
iii. Double click on the box labeled AC Sweep.
iv. The start frequency should be 1 kHz and the end frequency should be
1000 kHz. Select a reasonable number of total points to obtain a smooth
curve.
v. Click OK on the AC Sweep window and then OK on the SETUP window.
vi. You can unclick the small box to the left of the box labeled DC Sweep. If
you do not, you will have an option to select which simulation will be run
after you click the ANALYSIS/SIMULATE button.
vii. Go to ANALYSIS/SIMULATE or click on the yellow button
to begin
the simulation. Another window should open and a plot of the output
voltage versus frequency should appear.
viii. Print a copy of the graph.
c. Transient Analysis
i. Go to ANALYSIS/SETUP or click on the
button.
ii. Double click on the box labeled Transient.
iii. Select a final time such that the plot will contain one full cycle of the input
sinusoid.
iv. Again, you can unclick the small box to the left of the box labeled DC
Sweep. If you do not, you will have an option to select which simulation
v. Click OK on the Transient window and then OK on the SETUP window.
will be run after you click the ANALYSIS/SIMULATE button.
vi. Go to ANALYSIS/SIMULATE or click on the yellow button
to begin
the simulation. Another window should open and a plot of the output
voltage versus the input voltage should appear.
vii. Print a copy of the graph.
In your pre lab report, include a print out of your circuit and the three plots that you
obtained from your PSpice simulation runs. Answer the following questions:
1.
2.
3.
4.
5.
At what dc input voltage does the output voltage reach a maximum?
At what frequency does the output voltage drop to 2.5 V?
At what frequency does the output voltage equal the input voltage?
At what voltages does the output voltage get clicked during the cycle?
Are there any discrepancies between the results of your PSpice simulations (DC
vs. AC vs. Transient)?
Laboratory Exercise:
1. Build the inverting amplifier that you have designed using a function generator for your
input source. Select a sinusoid with an amplitude of 0.5V (1V peak-to-peak) and a
frequency of 1 kHz. The pin-out of the dual in-line package (dip) is given below.
2. Using the oscilloscope, measure the maximum output voltage in the positive and negative
halves of its cycle.
3. Adjust the frequency of the function generator until you obtain a maximum output
voltage of 2.5 V.
4. Compare these values to the values that you obtained from your PSpice simulation.