5: “OPERATIONAL AMPLIFIER IMPERFECTIONS AND APPLICATIONS”
[1, pg. 23]
ECE 3200 Electronics II
updated 1 June 2012
References
1. K. C. Smith, Laboratory Explorations for Microelectronic Circuits Fourth Edition, Oxford
University Press, 1998.
2. A. S. Sedra and K. C. Smith, Microelectronic Circuits, 6th ed., Oxford University Press, 2009.
Objectives
1. To investigate several non-ideal properties of operational amplifiers.
2. To build an integrator that compensates for some of the non-ideal properties of operational
amplifiers.
3. To investigate the small signal frequency response of an operational amplifier circuit.
4. To explore slew rate limiting in an operational amplifier circuit.
5. To improve and further develop an ability to effectively communicate technical information via a
written report.
Pre-Laboratory Assignment
(MUST BE COMPLETED INDIVIDUALLY)
As always, include a copy of the pre-lab results in your notebook.
1. We will be performing the experiments (labeled “E”) in experiment #2 of reference 1. Read these
experiments.
2. FOR THE PRELAB, USE THESE VALUES: =20 nA and =3 nA.
3. (E1.1) Complete P1.1. Note that , , and refer to the voltage at node C for parts a, b,
and c of E1.1, respectively.
4. (E2.1 and E2.2) For the compensated integrator of Figure 2.3, describe the function of each of
the components in this circuit. What, if any, operational amplifier imperfections are the passive
components addressing? By hand, prepare a Bode magnitude and phase plots for /
.
5. (E3.1) Use SPICE to obtain Bode magnitude plots of /
for the two circuit configurations to
be investigated in E3.1. Verify the low frequency gain and the 3dB frequencies for each case via
hand calculations. Assume ft =1MHz.
© 2012 Damon A. Miller
Page 1 of 2
6. Describe in detail how to measure the slew rate of an operational amplifier. Include a schematic
of the circuit that you will use.
Procedures
Follow our standard practice of fully documenting your results using notes, graphs, print-outs from
the scope, etc. Disregard “Analysis” steps unless otherwise directed.
1. Perform E1.1 “Voltage and Offset Currents” [1]. Complete the analysis section.
2. Perform E2.1 and E2.2 “Compensated Miller Integrator” [1]. For E2.2 parts (c) and (d), compare
your results to your prelab Bode plot.
3. Perform E3.1 “Small-Signal Frequency Response” [1].
4. Measure the slew rate of your operational amplifier.
Exercises
None.
Credits, Copyright, and Use
Refer to front matter available at http://homepages.wmich.edu/~miller/ECE3200.html for material
credits, further copyright information, and use guidelines.
© 2012 Damon A. Miller
Page 2 of 2