ENGR 43
Lab Activity
Student Guide
LAB 11 – Diode Characteristics
Student Name: ___________________________________________________
Overview
Getting Started
In this activity the student will characterize
standard PN and several special-purpose
diodes that are used in a variety of circuits,
including power supply and monitoring
circuits.
Lab Activity and Deliverables:
It should take students approximately 2
hours to complete the lab activity, and 1
hours of homework time to complete the lab
report.
Before Starting This Activity
Equipment & Supplies
Item
Diode, 1N4000 or
equivalent
Diode, 1N914 or equivalent
Schottky Diode, 1N5822 or
equivalent
Zener diode 1N4731 or
equivalent
Red LED
Green LED
Yellow LED
PC, NI-ELVIS and MultiSim
11 (or later) application
This activity assumes that the student has
already completed the introduction activities
for MultiSim and the NI-ELVIS trainer.
Download the following files from the
GoogleDocs site or the ENGR 43 course
website:
 Diode-tracer.ms11
 ENGR43Lab11.xlsx
 SpecScavengerHunt.docx
Learning Outcomes For Activity
Relevant knowledge (K), skill (S), or
attitude (A) student learning outcomes
K1. Identify the fundamental characteristics
and specifications for PN, Schottky,
zener, and light-emitting diodes.
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Special Safety Requirements
The MultiSim simulation allows you to
subject the virtual components to electrical
abuse that would damage real components.
Do not exceed the maximum ratings for the
components when characterizing the
components with the NI-ELVIS. If you do
not know the published maximum ratings,
refer to the manufacturer’s specification
sheet for the component.
K2. Describe the procedures and
precautions for functional testing of
various diode types.
S1. Collect and summarize data from diode
measurements.
S2. Calculate operating limits from diode
specification sheets.
Lab Preparation
A1. Increase awareness for the applications
of multiple diode types in electronic
systems.
LAB 11 – Diode Characteristics
ENGR 43
Qty
Verify that the NI-ELVIS trainer has the
standard proto test board installed, is
powered up, and connected via USB to the
lab PC.
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ENGR 43
Lab Activity
Student Guide
Task #1 – Diode Simulations
maximum power dissipation will be the
maximum forward current x forward
voltage drop.) Record your data in the
left side of Table 2.
This task has you evaluate several diodes
with the MultiSim IV Analysis tool.
1. Open the Excel worksheet
ENGR43Lab11.xlsx. Open the
MultiSim file diode-tracer.ms11.
Double-click on the IV Analysis tool.
Click on the Simulate Param button
and set Start to 0 V, Stop to 2 V, and
Increment to 10 mV. Start the
simulation, wait for the display to
produce the IV curve, and then stop the
simulation.
2. Use the cursor to read the current and
voltage values (IV data) along the curve.
Locate two points along the straight
section of the rising slope and record the
data in Table 1 of the Excel workbook.
These points will be used to determine
the equivalent forward resistance for
each diode.
3. Identify the voltage where the forward
current IF = 1 A. Click on the Simulate
Param button and set Stop to this
voltage. Start the simulation and find the
IV data at the approximate “knee” of the
curve, where it turns from flat to a steep
slope. Record this in Table 1.
4. Repeat steps 1-3 for the remaining
diodes. For the LEDs, use a Stop voltage
of 4V.
5. Similar to step 3, locate the reverse
breakdown voltage by entering a
negative Start voltage and finding the
point where the reverse current makes a
sudden increase. Enter the data in Table
1.
6. Refer to the data sheets for each
component. Locate the specs for
maximum forward current, maximum
power dissipation, and reverse
breakdown voltage. Note that the data
sheet may not include all three specs, but
you should be able to calculate them
from the specs provided. (For instance,
LAB 11 – Diode Characteristics
ENGR 43
Task #2 – NI-ELVIS 2-Wire CurrentVoltage Analyzer
Now that you have simulation data and
component specifications, you will use the
NI-ELVIS 2-Wire Current-Voltage
Analyzer to perform similar measurements
on real components. The major difference is
that care must be taken to avoid operating
the DUT outside of the maximum operating
limits.
1. For each device that you are going to
measure, determine your maximum test
limits for forward and reverse voltage
and current that allow you to stay within
the maximum ratings for each
component.
2. Open the NI-ELVIS 2-Wire CurrentVoltage Analyzer virtual instrument.
Connect the first component to the
DUT+ and DUT- on the ELVIS protoboard.
3. Set the voltage sweep and current limits
to values that will not damage the
component. Click Run and collect the
data. Enter the data in Table 3.
4. OPTIONAL: Repeat the measurements
on the curve tracer. Ask the instructor
for a demo on setting up and reading
data on the curve tracer.
Deliverable(s)
Print your Excel workbook and save it with
this activity guide in your Lab Activity
Binder.
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ENGR 43
Lab Activity
Student Guide
Lab 11 Summary Questions
Rectifier and Signal Diodes
The 1N4001 is commonly referred to as a “rectifier diode” and the 1N914 as a “signal diode.”
Refer to the manufacturer’s specifications and from your characterization data. Describe the
difference(s) between a “rectifier” and a “signal” diode.
Search the web for manufacturers (not distributors) of 1N4001 diodes. List some of the
manufacturers’ names.
What is the most significant difference in the forward bias characteristic of the 1N5822,
compared to the 1N4001? Why is this important for power supply circuits? (hint: think “power”)
LAB 11 – Diode Characteristics
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ENGR 43
Lab Activity
Student Guide
Zener Diodes
How did the forward bias characteristics of the zener diode compare with the 1N4001 and 1N914
diodes?
Describe two ways that the reverse bias characteristics of the zener diode differ from the 1N4001
and 1N914.
Light Emitting Diodes
Why does the forward “knee” voltage for an LED depend on the color of the LED? If you are not
sure, try searching Wikipedia for “Light-Emitting Diode” and examine the table listing the LED
colors.
How does the reverse breakdown voltage compare with the 1N4001 and 1N914? Considering
where LEDs are used, do you think this is a significant issue?
LAB 11 – Diode Characteristics
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