EE 420L Engineering Electronics II - Lab 1

Authored by David Flores

Due: January 30, 2019

Lab Description

· This lab consisted of an introduction on editing webpages in HTML on CMOSedu. As well as a review of basic RC Circuits

Pre-Lab

Your lab reports will be drafted using html and placed on CMOSedu.
Prior to the first day of lab, but no earlier than one week before the lab starts,request a CMOSedu account, using your UNLV email address (!), from Dr. Baker (rjacobbaker@gmail.com).
Review the material seen here covering editing webpages (do this before the first lab).
Read the entire write-up seen below before coming to lab

Practice Image on webpage as well as Index

Lab Instructions

For this first lab simulate, and verify the simulation results with experimental measurements, the circuits seen in Figs. 1.21, 1.22, and 1.24 (use a 1 uF cap in place of the 1 pF cap) of the book. Your results should be similar to, but more complete than, the simulation results seen on pages 17 - 23. In your report, and for each circuit, show the

Circuit schematic showing values and simulation parameters (snip the image from LTspice).
Hand calculations to detail the circuit's operation.
Simulation results using LTspice verifying hand calculations.
Scope waverforms verifying simulation results and hand calculations.
Comments on any differences or further potential testing that may be useful (don't just give the results, discuss them).

For the AC response seen in Fig. 1.23 generate a table showing some representative measurement results (frequency, magnitude, and phase).

Show the lab TA how you are making these measurements.

If you would like to include a plot of this measured data then using a plotting program, such as Excel, add the image to your report.

Experiment 1: Figure 1.21

LTSpice schematic from Fig 1.21 Hand Calculations from Fig 1.21

LTSpice waveform Vout and Vin. (Vout pk-pk 1.243mV) Oscilloscope Measurement from Fig 1.21

(yellow input, blue output)

Fig 1.21 Frequency (200Hz)	Amplitude (pk-pk)	Phase (
LTSpice	1.243V	-51.6
Hand Calculations	1.246V	-51.5
Oscilloscope	1.24V	-50.7

LTSpice Frequency Response of Fig 1.21

Frequency (Hz)	LTSpice Magnitude (dB)	LTSpice Phase (	Oscilloscope Phase Vout ( )
2	-0.685m	-0.719	0
20	-68.5m	-7.19	8
200	-4.15	-51.6	51.2
2k	-22.1	-85.5	2/Inconsistent
20k	-41.9	-89.5	Inconsistent

Comments: In this experiment we noticed that as we increased the frequency the amplitude of Vout decreased. As we increased the Frequency we also noticed that when we got into the rage of about 2k or above that frequency the oscilloscope would have trouble detecting the difference in phase of the two waveforms. In the future using a better Oscilloscope might be a solution one that could read difference in phase even at higher frequencies. Or another idea might be to measure the waveform on the oscilloscope manually as opposed to using the built-in feature which might have some slight percent error. Other than that, all the Amplitude were within a 0.5% error, Phase at 200Hz within a 2% error. The only inconsistency came with the phase at higher frequencies.

Experiment 2: Figure 1.22

LTSpice schematic from Fig 1.22 Hand Calculations from Fig 1.22

LTSpice waveform Vout and Vin. (Vout pk-pk) Oscilloscope Measurement from Fig 1.22

(yellow input, blue output)

Fig 1.22 Frequency (200Hz)	Amplitude (pk-pk)	Phase (
LTSpice	1.418V	-5.86
Hand Calculations	1.38V	-6.84
Oscilloscope	1.50V	-7.57

Comments: For this experiment we used a 2.2uF capacitor in the LTSpice simulation as well as for the oscilloscope measurements as opposed to a 2uF in the book. I used the 2uF for the hand calculations, so we could see the percent error. There is about an 8%error with the Hand Calculations and the Oscilloscope this was expected because of the changed capacitor value. The percent error between LTSpice and Hand Calculations is about 5% better just not as accurate as Experiment 1.

Experiment 3: Figure 1.24

LTSpice Schematic from Fig. 1.24 Hand Calculations from Fig. 1.24

LTSpice waveform Vout and Vin of Fig. 1.24 Oscilloscope Measurements of Fig. 1.24

Based on the LTSpice simulation we can conclude that we calculated the period to be 10ms, which we can see that it takes about 5ms to fully charge, and about 10ms to fully charge and discharge also known as the period. This matches our results from the oscilloscope almost exactly.

Comments: Basic RC circuit for this experiment all past knowledge just good review to understand future material. The results are almost identical so there should be no confusion there. Everything worked as expected.

Conclusion: These Experiments were great to start back up. They gave me practice with a few basic RC circuits not to difficult to understand but enough work to have to go back and do some review LTSpice, Oscilloscope work, and frequency response.

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