LAB I. INTRODUCTION TO LAB EQUIPMENT
1. OBJECTIVE
In this lab you will learn how to properly operate the basic bench equipment
used for characterizing active devices:
1. Oscilloscope (Agilent MSO6032A),
2. Source Measure Unit (SMU) (Keithley 2430),
3. Function generator Agilent 33220A, and a
4. Bread board.
You will use these tools to characterize three simple resistive circuits, perform
theoretical circuit analyses on them, analyze the results, and present your
findings in a concise, organized lab report.
2. OVERVIEW
The Background Information section in this lab manual describes the basic
operations of each lab equipment. You are expected to learn these basic
operations during lab, ideally before moving on to the Lab Procedure
section. The lab procedure will test your comprehension of the background
materials by asking you to build simple resistive circuits and use the bench
equipment to characterize them.
Information essential to your understanding of this lab:
1. Background Material
Materials necessary for this experiment:
1. Standard bench equipment.
2. Two resistors: 3.3 kΩ and 5.1 kΩ.
3. Two 10:1 Oscilloscope Probes.
4. One RG58C/U Coaxial Cable.
5. Two Red & Black Test Lead Pair (Banana-Plug to Alligator-Clip.)
3. BACKGROUND INFORMATION
3.1 BREADBOARD BASICS
Breadboards (aka. Solderless board, Prototype board) are simply a set of
pre-wired interconnected strips that are accessible through periodically
spaced hole in the board. Looking at Figure 1., you can identify which holes
form an interconnected strip by the black lines connecting them. By
plugging the lead of a component into a hole you will be connected to all
the other components in that strip without permanently connecting them.
This allows you to build, alter, and test your prototype circuits quickly.
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There are two basic types of strips. The first type is called connection strip,
they typically take up most of the board and are connected horizontally.
Each hole can uniquely identified using the labels “a-j’ column labels and ‘163’ row labels. NOTE: ‘a-e’ connection strips are not connected to the ‘f-i’
connection strips. The second type is called bus strip. ALL the holes in a bus
strip are connected vertically. Bus strips are typically labeled ‘A’ or ‘B’ and
are marked by a red or blue line along their length.
Figure 1. A schematic diagram of the breadboard showing buses and strips.
3.2
KEITHLEY SOURCE MEASURE UNIT 2400
The Keithley SMU can be used as a voltage source, a current source, a
voltmeter, or an ammeter. Examine Figures 2. & 3. below before moving
on to studying the main functions of the Keithley SMU.
Figure 2. Keithley SMU button descriptions.
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Figure 3. Front panel of Keithley 2430 SMU.
3.2.1 SET VOLTAGE/CURRENT SOURCE CONFIGURATION
In order to use the Keithley SMU as a voltage source or a current
source, you need to follow the steps given below.
1. Press the V or I button in the Source group.
2. Press the EDIT button (top left): The display value Vsrc or Isrc should
start blinking. If it is not blinking press the EDIT button again.
3. To set your source value, you need to use the following buttons:
 Select Range: These buttons are used to change the range
of the source value by an order of magnitude (i.e. by a
factor of 10).

Select Digit: The Left and Right arrows in the EDIT
group are used to select the digit you wish to alter.

Select Number: The Up and Down arrows in the
source group are used to change the digit value.
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Or you can enter the numbers directly using these buttons:
4. Once you set the value, press Enter.
3.2.2 COMPLIANCE (IMPORTANT!!!)
Once you have set your source value, you need to set your compliance
value.
How do I set the compliance value? Press the “Edit” button twice. You will
see a set of digits blink. Use the same buttons you used to set your source
value above to set your compliance value.
How do I determine compliance value? Use data sheets to determine the
voltage and current limits of your component. Next, use your magical powers of
electrical engineering (also known as the mystical art of ‘circuit analysis’) to
figure what voltage and current your component will experience. For example
the average resistor is rated at a ¼ watt. If you put 1V across that resistor, you
need to make sure – as a good and employable electrical engineer – that you
don’t put more that 0.25A through it. Therefore, if you set up the SMU as a
voltage source delivering 1V to your resistor, your compliance value will be
250mA.
What is compliance? Compliance is a safety feature incorporated in the
Keithley SMU to protect your circuit components from unexpected high
power of operation – i.e. it prevents you from unexpectedly ‘frying’ your
circuit. It is a limiting factor input by the user.
If you set up an SMU as a voltage source, you must also set the highest
current value the SMU is allowed to provide to your circuit; this is called
“current clamping”.
If you set up an SMU as a current source, you must set the highest voltage
value the SMU is allowed to provide to your circuit; this is called “voltage
clamping”.
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On the screen, the compliance value is typically displayed to the right of the
source value, and in this format: “Cmpl: 073.000 mA” (assuming you set
up a voltage source.)
Once you have set up source and compliance for an SMU, you can push the
ON/OFF button at the bottom right corner of the front panel to power your
circuit. Check the compliance value in the display. If something blinks, there is
a problem.
If you turn on your SMU and your circuit attempts to draw more current
than is allowed by your compliance value, the “Cmpl:” text will blink (ex.
“Cmpl: 073.000 mA”; here bold text indicates blinking text). This is called
“breaking real compliance”. To overcome this, you need to increase the
compliance value – or recheck your circuit setup.
If the units portion of your compliance value blinks (“Cmpl: 073.000 mA”),
you “broke ‘range’ compliance”. It means the compliance value you entered
is well above the range of current values being drawn by your circuit. The
actual current drawn is below the range of measurement of the SMU. You
need to press the “AUTO” button to allow the Keithley to set the compliance
value to some lower value.
3.2.3 VOLTMETER / AMMETER CONFIGURATION
To configure the Keithley SMU as an Ammeter or a Voltmeter, do the following:
Voltmeter Setup:
1. Set the SMU up as a current source with zero output current.
2. Then from the control panel area, press the V button in the MEAS group
under the display.
Ammeter instructions
1. Set the SMU up as a voltage source with zero output voltage.
2. Then from the control panel area, press the I button in the MEAS group
under the display.
3.3 AGILENT MSO6000 SERIES OSCILLOSCOPE
This section will instruct you on how to operate the Agilent 6000 Series
Oscilloscope.
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Figure 4. Front Panel of Agilent 6000 Series Oscilloscope
3.3.1 OSCILLOSCOPE FRONT PANEL CONTROL

Intensity Control (2 in Fig. 4)
Rotate clockwise to increase the display intensity; counterclockwise to
decrease. You can vary the intensity control to bring out signal detail,
much like an analog oscilloscope. Digital channel waveform intensity is
not adjustable.

Autoscale Key (24 in Fig. 4)
When you press the Autoscale key the oscilloscope will quickly determine
which channels have activity, and it will turn these channels on and scale
them to display the input signals.

Vertical Position Control (6 in Fig. 4)
Use this knob to change the channel’s vertical position on the display. There
is one Vertical Position control for each channel.
Channel On/Off Key (7 in Fig. 4)
Use this key to switch the channel on or off, or to access the channel’s
menu in the soft-keys. There is one Channel On/Off key for each channel.
Vertical Sensitivity (9 in Fig. 4)
Use this knob to change the vertical sensitivity (gain) of the channel.


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





AutoProbe Interface (10 in Fig. 4)
When you connect a probe to the oscilloscope, the AutoProbe Interface
attempts to determine the type of probe and set its parameters in the
Probe menu accordingly.
Horizontal Delay Control (18 in Fig. 4)
When the oscilloscope is RUNning, this control lets you set the
acquisition window relative to the trigger point. When the oscilloscope is
STOPped, you can turn this knob to pan through the data horizontally.
This lets you see the captured waveform before the trigger (turn the
knob clockwise) or after the trigger (turn the knob counterclockwise).
Horizontal Sweep Speed Control (20 in Fig. 4)
Turn this knob to adjust the sweep speed. This will change the time per
horizontal division on the display. When adjusted after the waveform has
been acquired and the oscilloscope is stopped, this has the effect of
stretching out or squeezing the waveform horizontally.
Measure Keys (21 in Fig. 4)
Press the Cursors key to switch on cursors that you can use for making
measurements. Press the Quick Meas key to access a set of
predefined measurements
Entry Knob (23 in Fig. 4)
The entry knob is used to select items from menus and to change values.
Its function changes based upon which menu is displayed. Note that the
curved arrow symbol above the entry knob illuminates whenever the
entry knob can be used to select a value. Use the entry knob to select
among the choices that are shown on the softkeys.
Softkeys (25 in Fig. 4)
The functions of these keys change based upon the menus shown on the
display directly above the keys.
Probe Attenuation Factor: Some Oscilloscope probe attenuates the
incoming signal by a certain factor. In this lab, we use 10:1 probe which
attenuates the incoming signal by a factor of 10. By matching the
attenuation factor of the oscilloscope to the attenuation of the probe, your
measurements will reflect the actual voltage levels at the probe tip.
Basic 10:1 probe calibration procedure:
1. Press the Save/Recall key on the front panel and then press the
Default Setup Softkey (located directly below the display on the
front panel). The oscilloscope is now configured to its default
settings.
2. Select a probe and set the physical switch on the lead to 10x.
3. Connect the probe to channel 1, press the (1) button.
4. Ensure the resistance is set at “1Mohm” on screen.
5. Press the softkey marked above “Probe”. Set the probe attenuation
factor to “10:1”.
6. Connect the oscilloscope probe to the Probe Comp signal terminal
on the front panel.
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7. Connect the probe’s ground lead to the ground terminal next to the
Probe Comp terminal.
8. Press Autoscale.
9. You should see a waveform on the oscilloscope’s display similar to this:
6. If the square wave form is not shaped correctly, it implies that the
probes are not compensated to match to the oscilloscope’s channels. In
order to compensate the probe, you should adjust the trimmer capacitor
of the probe (located on the probe BNC connector) for the flattest pulse
possible using the plastic flathead driver provided with the probe.
3.3.2 MEASURING VOLTAGES AND TIME-RELATED PARAMETERS
When measuring voltages with the oscilloscope, place the probes in parallel
across the component where the voltage signal is being measured. Once
you have the signal displayed on the screen, you can use buttons and keys
to do the measurements.

To measure RMS, DC, or peak to peak voltages with the oscilloscope, use
the following method:
Press the Quick Meas button on the Measure keys section (21 in
Fig. 4). The Select menu appears on the bottom of the screen. Press
the button beneath that, or use the “Entry Knob” (23 in Fig. 3) to
select the desired value like RMS, Amplitude, Average, Peak to peak
etc. The selected value would be displayed on the bottom of the
display.

To measure Frequency, period and other time-related parameters with
the oscilloscope, use the following method:
Press the Quick Meas button on the Measure keys section (21 in
Fig. 4). The Select menu appears on the bottom of the screen. Press
the button beneath that, or use the “Entry Knob” (23 in Fig. 3) to
select the desired value Frequency, delay, period, Duty cycle etc. The
selected value would be displayed on the bottom of the display.

For other measurements related to the voltage and time-related
parameters, we use cursors. To measure using the cursors do the
following:
Cursors are horizontal and vertical markers that indicate X-axis
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values (usually time) and Y-axis values (usually voltage) on a
selected waveform source. The position of the cursors can be
moved turning the Entry knob. When you press the Cursors key,
it will illuminate and the cursors will turn on. To turn cursors off,
press this key again until it is not illuminated, or press the Quick
Meas key.
Cursors are not always limited to the visible display. If you set a
cursor, then pan and zoom the waveform until the cursor is off
screen, its value will not be changed, and if you pan the waveform
back again it will have the cursor in the original place. The
following steps guide you through the front-panel Cursors key.
You can use the cursors to make custom voltage or time
measurements on the signal.
1. Connect a signal to the oscilloscope and obtain a stable display.
2. Press the Cursors key. View the cursor functions in the softkey
menu:
 Mode Sets the cursors to measure voltage
and time (Normal), or displays the binary
or hexadecimal logic value of the displayed
waveforms.




Source Selects a channel or math function
for the cursor measurements.
X Y Selects either the X cursors or the Y
cursors for adjustment with the Entry
knob. X1 and X2 Adjust horizontally and
normally measure time.
Y1 and Y2 Adjust vertically and normally
measure voltage.
X1 X2 and Y1 Y2 Move the cursors
together when turning the Entry knob.
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Cursor Examples
1. Cursors measure pulse widths other than middle threshold
points
2. Cursors measure frequency of pulse ringing
3.3.3 MEASURING CURRENTS
The Oscilloscope can only measure current indirectly, by reading the voltage
across a resistor while it is in a circuit and then applying Ohm’s Law to find
the current. If you have two signals and want to find the phase between
similar points select the source of measurement for cursor 1 as channel 1
and the source for cursor 2 as channel 2. The difference readout is the
delay between the two signals. If you divide that delay by the period then
you have the phase value as a fraction of 360°, or 2π radians. If you would
like to represent that in degrees all you have to do is convert it from radians
to degrees.
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3.4. FUNCTION GENERATOR AGILENT 33220A
The function generator is used to generate signals for your circuits. You will
need to know how to set the function generator to get sine, square, triangle or
ramp signals. In addition, you will have to set up the frequency, the amplitude,
offset voltage and the duty cycle.
The default settings for this instrument are a sinewave of 1 kHz, with an
amplitude of 100 mV and a DC offset of 0.0 V.
Figure 5. Front panel of the Agilent 33220A function generator.
The function generator is very easy to use since each function has a specific
button. If you want to select a waveform, just look for the button with the
desired waveform such as a sine wave, a square wave, triangle wave, or ramp
wave. Then, just press its button. All that you have to do now is set the
parameters for the waveform. To set the frequency, amplitude, offset or the
duty cycle you need to do the following:
1. Press the appropriate gray buttons beneath the display screen
(Freq/Period, Ampl/Hi Level, Offset/Lo Level, or Duty Cycle).
2. You may enter the value one of two ways.
a.) Turn the knob and the highlighted digit will change. You may
select a different digit by using the < or the > buttons.
b.) You can also key in the digit by using number buttons.
3. Press “Output” button on the bottom right of the front panel (right
next to Sync cable) and make sure the light is “on”.
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IMPEDANCE MATCHING (IMPORTANT!)
In order to make sure you read the exact value of the amplitude output by the
function generator, You should make sure the output impedance of the function
generator is matched to the impedance of the connected circuits.
This function generator has 50 Ω output impedance. It has been configured by
the manufacturer to deliver the voltage signal when a load of 50 Ω is attached
to it. In the case of large impedance circuits the function generator may deliver
up to twice the voltage that you have set it up to deliver.
In our case, we use a series connected 5.1 kΩ resistor and 3.3 k Ω resistor,
which is much higher than 50 Ω. Hence, when you set 1 Vpp on the function
generator, you will observe twice the amplitude (2 Vpp) on the oscilloscope. In
order to overcome this, you need to set the function generator to have “High
Z” output impedance. To do this, press the “Utility” button and press the
“output setup” and you can change the “output impedance” to the “High Z”
output mode.
4. PREPARATION
There is no preparation for this lab except for reading and learning the
background material.
5. PROCEDURE
Before proceeding with the lab, please familiarize yourself with setting up the
bench equipment. Refer to Section 3 for details.
5.1 FUNCTION GENERATOR AND OSCILLOSCOPE
Use the function generator and the oscilloscope to perform the following tasks.
1. Build circuit ‘A’ shown below in Figure 6.
2. Set the function generator to generate a sinusoidal signal with a
frequency of 100 Hz and peak-to-peak voltage of 5V.
3. Set up one probe across the whole circuit, and another across R2.
4. Subtract Channel 2 signals from Channel 1 signals using the
Oscilloscope.
5. Measure the voltages and time related parameters asked for on the
Instructor Verification Sheet. Obtain TA Signature.
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Figure 6. Circuit ‘A’
5.2 KEITHLEY SMU
Use the two Keithley SMUs to perform the following tasks:
5.2.1 Using the circuit ‘B’ of Figure 7 set up a Keithley SMU as a voltage
source of 10 V DC. Figure out the compliance by evaluating the
circuit. Use the second Keithley SMU to measure the voltages in R1
and R2. Measure the current in the circuit directly from the Keithley
SMU used as the voltage source. Record values on IV sheet.
5.2.2 Using the circuit ‘C’ of Figure 8, set up a Keithley SMU as a current
source of 5 mA DC. Set up the other Keithley to measure the current
in R1 and in R2. Record Values on IV Sheet.
5.2.3 Measure the impedance of your two resistors using the Ohmmeter
setting of a Keithley SMU. Record the values in the Instructor
Verification Sheet. Get TA Signature.
Figure 7. Circuit 'B'
Figure 8. Circuit 'C'
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Notice that Circuits ‘B’ and ‘C’ are source transforms of each other. You
should be able to compare and contrast the voltage and current
measurements.
6. LAB REPORT
Type a lab report with a cover sheet containing your name, class (including
section number), date of the lab, and the report due date. Use the following
outline to draft sections of your lab report:
Abstract: Briefly describe the purpose of the lab, the analysis
you performed, and your findings.
Introduction: Briefly mention the bench equipment you used
in the lab and their basic functions in your own words.
Procedure: You do not need to provide a procedure section
for this lab.
Data Presentation: Report all the measured data collected.
Make sure it is well presented, has units and labels - and is
easily discernable which values are from a particular section
of the procedure. Please use Excel, Matlab or another
software to help generate well-formed tables.
Analysis: Perform theoretical circuit analysis on each circuit
you characterized – i.e. use the measured values of your
resistors (5.2.3) to find the theoretical voltage and current
values for circuit ‘A’, ‘B’, and ‘C’. Do show work – typed
equations, units etc. Include the circuit diagrams in your
descriptions, if needed. Compare your calculated values to the
measured values using percent error calculations. Be sure to
organize your analyses appropriately according to procedure
section number.
Conclusions: What conclusions can you draw about using
bench equipment from your direct experience of setting it up
and using it to characterize circuits? What do the results of
your circuit analyses tell you about your bench equipment?
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