Tektronix TDS3000C Series User manual

Troubleshooting Your Design
with the TDS3000C Series Oscilloscopes

2
www.tektronix.com/tds3000TDS3000C Series Oscilloscopes

3
www.tektronix.com/tds3000TDS3000C Series Oscilloscopes
Table of Contents
Getting Started . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
Debug Digital Timing Problems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
Debug Rise Time and Fall Time Problems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
Debug Threshold Problems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
Debug Digital Logic Problems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
Capture Elusive Glitches and Waveform Anomalies . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 - 10
Check Signal Integrity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 - 12
Test For Presence of Video Signals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
Test Each Line of a Video Signal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
Determine if this Video Signal is the Desired Video Signal . . . . . . . . . . . . . . . . . . . . . . . . . . 15
Check Video Color Signals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
Check the Quality of a Communications Signal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .17 - 19
Make a Quick Pass/Fail Test of a Device-under-test (DUT) . . . . . . . . . . . . . . . . . . . . . . . . . . 20
Look for Unintentional Circuit Noise . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
Remote Troubleshooting Using Your Computer’s Browser . . . . . . . . . . . . . . . . . . . . . . . . . . 22

4
www.tektronix.com/tds3000TDS3000C Series Oscilloscopes
Getting Started
To optimize your measurements, it is important
to start at the beginning – by compensating
your probes and returning your oscilloscope to
a known state.
To compensate your probe, follow these
simple steps:
1. Connect the probe to channel 1.
2. Attach the probe tip and reference lead to the
Probe Comp connectors. If using the probe hook-tip,
ensure a proper connection by firmly twisting the tip
onto the probe.
3. Push Autoset.
4. Check the shape of the
displayed waveform to
determine if your probe
is compensated correctly.
5. If necessary, adjust your probe. Repeat as needed.
To return your oscilloscope to a known state,
follow these simple steps:
1. Press the front panel Save/Recall menu button.
2. Press the Recall Factory Setup bottom screen
menu button.
3. Press the OK Confirm Factory INIT side screen
menu button.
4. Press the front panel Autoset button.
Autoset
button
Probe
Comp
Channel 1
Adjusting Probe P6139A
Overcompensated
Undercompensated
Compensated Correctly

Debug Digital Timing Problems
5
www.tektronix.com/tds3000TDS3000C Series Oscilloscopes
Digital designers need to quickly find and analyze a
wide range of circuit timing problems. For example,
race conditions and transients can cause circuits to
perform inaccurately. The TDS3000C Series’ pulse
width trigger can help troubleshoot such situations
by triggering when a signal pulse width is less than,
greater than, equal to or not equal to a specified
pulse width.
To use the pulse width trigger to capture a
glitch:
1. In the Trigger section, press the Menu button.
2. In the bottom menu, press Type until Pulse is selected.
3. In the bottom menu, press Class to select Width.
4. Select, as desired, Source, Polarity, Trigger When,
Level and Mode & Holdoff.

6
www.tektronix.com/tds3000TDS3000C Series Oscilloscopes
Debug Rise Time and Fall Time Problems
Both analog and digital electronics designers
face problems related to slow edges (the rate of
change of volts over time), as measured by the
rise or fall time. The signal’s edge speed, known
as the slew rate, can affect the operation of
digital bus transceivers, transmission lines and
op-amp circuits. The TDS3000C Series’ slew
rate trigger can help troubleshoot such situations
by capturing waveforms where the slew rate is
less than, greater than, equal to, or not equal
to a specified rate. Automatic measurements
can supply supporting data.
To use the slew rate triggers:
1. In the Trigger section, press the Menu button.
2. In the bottom menu, press Type until Pulse is selected.
3. In the bottom menu, press Class to select Slew Rate.
4. Select, as desired, Source, Polarity, Trigger When,
Thresholds, and Mode & Holdoff.
To run automatic measurements:
1. Press the front panel Measurebutton.
2. Press the Select Measurement bottom menu button.
3. Select the desired measurements from the side menu.

Debug Threshold Problems
7
www.tektronix.com/tds3000TDS3000C Series Oscilloscopes
Digital designers must quickly find and analyze
bus contention and other threshold problems.
The runt pulse trigger is useful to troubleshoot
such situations. A runt pulse is an illegal digital
signal that re-crosses a first threshold level before
crossing a second threshold level. A positive
runt pulse is a signal that first re-crosses the low
threshold level; a negative runt pulse is a signal
that first re-crosses the high threshold level.
To use the runt pulse triggers:
1. In the Trigger section, press the Menu button.
2. In the bottom menu, press Type until Pulse is selected.
3. In the bottom menu, press Class to select Runt.
4. Select, as desired, Source, Polarity, Trigger When,
Thresholds, and Mode & Holdoff.

8
www.tektronix.com/tds3000TDS3000C Series Oscilloscopes
Debug Digital Logic Problems
Digital designers must troubleshoot logic condi-
tions on digital circuits. They may need to deter-
mine what happens when, or if, two signals meet
a Boolean trigger condition. They may want to
evaluate conditions when two signals become
logically true or false, such as from the output of
a two-input AND, OR, NAND, or NOR logic gate.
When troubleshooting digital logic synchronous
state machines, designers may want to determine
if a state signal is true or false at the time a clock
signal transition is true. The TDS3000C Series’
logic triggers, such as its pattern and state
triggers, can be used to tackle these problems.
To use these logic triggers:
1. In the Trigger section, press the Menu button.
2. In the bottom menu, press Type until Logic is selected.
3. In the bottom menu, press Class to select either
Pattern or State.
4. Select, as desired, Inputs, Trigger When, Thresholds,
and Mode & Holdoff.
5. For pattern triggers, also define whether to trigger on
AND, OR, NAND, or NOR conditions.

Capture Elusive Glitches and Waveform Anomalies
9
www.tektronix.com/tds3000TDS3000C Series Oscilloscopes
In today’s high-speed digital designs, elusive glitches
and random anomalies can cause circuits to fail.
The TDS3000C Series speeds anomaly detection
with its digital phosphor technology and patented
WaveAlert waveform anomaly detection feature.
The TDS3000C Series employs digital phosphor
technology to capture and display infrequent wave-
forms or waveform variations. Its real-time intensity-
grading provides you with information about the
frequency of occurrence of signal amplitudes
and widths, making it easier to understand the
characteristics of the transients you’ve captured.
To fully utilize the TDS3000C Series’
digital phosphor technology:
1. Press the Display button to show the display menu.
2. Press Waveform Display on the bottom menu.
3. Confirm that Persist Time on the side menu is set to
Auto.
4. Press the Clear Persistence side menu button.
5. As desired, select the Backlight Intensity and
Graticule settings.
6. As desired, rotate the Waveform Intensity front
panel knob to adjust the persistence of the anomalous
waveform.

10
www.tektronix.com/tds3000TDS3000C Series Oscilloscopes
Capture Elusive Glitches and Waveform Anomalies (continued)
The TDS3000C Series’ WaveAlert waveform anom-
aly detection feature speeds your troubleshooting
task by helping you find elusive problems faster.
WaveAlert monitors the incoming signals on all
channels and will detect and highlight any wave-
form that deviates from the “normal” waveform
being acquired. You have full control over how
sensitive WaveAlert is to changes, and you can
select from several actions for the oscilloscope to
take when it finds a problem – stop the acquisition,
sound a beep, print the problem waveform and/or
save the problem waveform to disk.
To use the WaveAlert waveform anomaly
detection feature:
1. Display the waveform on the screen.
2. Press the Acquirefront panel menu button.
3. Press the WaveAlert menu button.
4. Press the WFM Anomaly Detection side menu
button to select On.
5. Press the Highlight Anomalies button to select On.
6. Rotate the general-purpose knob to set the comparison
sensitivity value.
7. Use the Waveform Intensity front panel button to
adjust the persistence of the anomalous waveform.

Checking Signal Integrity
11
www.tektronix.com/tds3000TDS3000C Series Oscilloscopes
Electronics engineers may discover that a wide
array of unintentional electrical events will make
a difference in how circuits function in the real
world. To characterize these events, engineers
can measure criteria such as overshoot, ringing,
ground bounce, cross talk, and other signal
integrity issues. The TDS3000C Series’ cursors
and automatic measurements can be used to
take such measurements.
To make signal integrity measurements
using cursors:
1. Press the Cursor button.
2. Press the Function menu button.
3. Press the H Bar Units (or V Bar Units) menu
button to select H Bar (or V Bar) cursors.
4. Place one cursor, as desired, using the
general-purpose knob.
5. Press the
Select button.
6. Place the other cursor, as desired, using the
general-purpose knob.
7. View the measurement (between cursors, or absolute)
on the upper right corner of the display.
Dreadouts indicate the difference between the cursor positions.
For H Bar cursors, @ readouts indicate the location of the active cursor relative to zero volts.
For V Bar cursors, @ readouts indicate the location of the active cursor relative to the trigger point.

12
www.tektronix.com/tds3000TDS3000C Series Oscilloscopes
Checking Signal Integrity (continued)
To make signal integrity measurements
using automatic measurements:
1. Press the Measure front panel button.
2. Press the Select Measurement bottom menu button.
3. Press the More side menu button until you find the
desired measurements. In this example, look for the
positive and negative overshoot measurements.
4. Select Positive Overshoot and Negative Overshoot
from the side menu buttons.
5. View the measurements selected on the right side of
the display.

Test for the Presence of Video Signals
13
www.tektronix.com/tds3000TDS3000C Series Oscilloscopes
Video technicians must perform a quick check
for the presence of a video signal at different test
points. If the site is in the field, technicians will
need lightweight, portable test equipment gear
that they can easily carry to each location.
The TDS3000C Series, with its optional battery-
powered operation and video trigger features,
make this oscilloscope a valuable tool for these
technicians.
To use the TDS3000C Series’ video
trigger to quickly check for the presence
of a video signal:
1. Connect the oscilloscope to the video signal using
proper adapters and a 75 Vterminator, if necessary.
2. Press the Acquire menu button.
3. Press the Autoset bottom button.
4. Press the Video Autoset* side button. If a broadcast-
standard video waveform is present, the oscilloscope
will display a stable video waveform that is triggered
on all lines.
5. Adjust vertical position and scale as desired.
6. If desired, reconnect the oscilloscope to other test
points. You do not need to change any oscilloscope
settings.
*TDS3VID or TDS3SDI video application modules required.
Otherwise, video triggering must be set up manually.

14
www.tektronix.com/tds3000TDS3000C Series Oscilloscopes
Test Each Line of a Video Signal
Video technicians may need to check one or
more video lines. They may need to search for
defective pixels in a Charge-Coupled Device
(CCD) video camera. The TDS3000C Series’
video triggers enable technicians to test each
line of a video signal.
To use the TDS3000C Series’ video trigger
to check each line of a video signal:
1. Connect the oscilloscope to the video signal using
proper adapters and a 75 Vterminator, if necessary.
2. Press the QuickMenu button.
3. If needed, press the Menu bottom button to display
Video.
4. Press the Video Autoset* bottom button until Lines
is displayed.
5. Press the
Field/Line side button to select the
proper line type. Even and Odd signify even and
odd lines/fields, respectively. When viewing lines,
Autoset will select Fast Trig for you.
6. If you have selected Line in Field/Line section, you
can now rotate the general-purpose knob to examine
each video line.
7. Adjust vertical position and scale as desired.
*TDS3VID or TDS3SDI video application modules required.
Otherwise, video triggering must be set up manually.

Determine if this Video Signal is the Desired Video Signal
15
www.tektronix.com/tds3000TDS3000C Series Oscilloscopes
Video technicians want to determine if the
displayed signal is the desired signal. Is it the
news program or the sports program? With
the TDS3000C Series, these technicians can
make this determination by simply viewing a
picture image of the video source.
To apply the TDS3000C Series’ video
trigger to determine whether or not
the video signal is the desired signal by
using the video picture mode:
1. Press the Display menu button.
2. Press the Video Picture menu button.
3. Press the Picture menu button to select On.
TDS3VID or TDS3SDI video application modules required.

16
www.tektronix.com/tds3000TDS3000C Series Oscilloscopes
Check Video Color Signals
Video technicians need to check for chroma (color)
level problems and to adjust video equipment to
solve any such problems. The TDS3000C Series
can function as a vectorscope with built-in gratic-
ules for 100% or 75% color bars to enable these
technicians to measure chroma levels and view
color signal phase and amplitude problems.
To use the TDS3000C Series’ vectorscope
mode:
1. Connect the Y’ signal to Ch1, the P’b signal to Ch2,
and the P’r signal to Ch3.
2. Press the Display front panel button to show the
display menu.
3. Press the Vector Scope bottom menu button.
4. Press the Ch2 vs. Ch3 (P’b vs. P’r) side menu button.
5. To scale and place the image, adjust the front panel
Vertical Scale and Vertical Position knobs as desired
with Ch2 (horizontal) and Ch3 (vertical) selected.
6. To more accurately scale and position the vector
display, press the Vertical Menu front panel button
and the Fine Scale bottom button, and rotate the
general-purpose knob.
TDS3VID or TDS3SDI video application modules required.

Check the Quality of a Communications Signal
17
www.tektronix.com/tds3000TDS3000C Series Oscilloscopes
Communications engineers and technicians must
test the quality, or performance, of a communica-
tions signal. Intense time-to-market pressures
require that they do so quickly and efficiently. The
TDS3000C Series, with its mask testing capability,
constellation diagrams and eye diagrams, is an
ideal tool for these developers.
Manufacturing engineers in a telecommunications
environment may need to compare the actual per-
formance of equipment on the production line with
“masks” of telecommunications standards. The
TDS3000C Series’ mask testing capabilities make
this oscilloscope an ideal test tool for these manu-
facturing engineers.
To use the TDS3000C Series’ pass/fail
mask testing capabilities:
1. Press the QuickMenu front panel button.
2. Press the Menu bottom menu button to display
Telecom.
3. Press the two Standard buttons to select and display
a mask.
4. Press Autoset to position the waveform in the mask
and adjust the gain and position settings as necessary.
5. Press the bottom and side menu buttons to set test
and pass/fail parameters.
6. Press the Run Test side button to run pass/fail testing.
Requires TDS3TMT telecommunications mask testing module.

18
www.tektronix.com/tds3000TDS3000C Series Oscilloscopes
Check the Quality of a Communications Signal (continued)
Some communications signals are encoded in a
Quadrature Amplitude Modulation (QAM) format.
To test the distortion of such a signal, engineers
can use the TDS3000C Series to generate a
constellation diagram and analyze the clarity of
the signal’s amplitude and phase at discrete
times in the diagram.
To obtain a constellation diagram using the
TDS3000C Series oscilloscope:
1. Connect the three signals to the oscilloscope using
proper probe techniques.
2. Press the front panel Display button.
3. Press the bottom XY Display menu button.
4. Press the side Gated XYZ menu button to select
the Z (gate) source channel.
5. If needed, press the side Ch1 (x) Versus menu button
to select the Y signal (Ch2 is the default).
6. Press the side Gated By menu button to select the
Z (gate) source channel.
7. Rotate the general-purpose knob to enter a value.
8. To properly place and scale the image, adjust the
Vertical Scale and Vertical Position with Ch1
(horizontal) and Ch2 (vertical) selected.

Check the Quality of a Communications Signal (continued)
19
www.tektronix.com/tds3000TDS3000C Series Oscilloscopes
Communications technicians must characterize
how well a communications signal complies with
international standards by determining if the signal’s
bits are accurately crossing the communications
channel. The TDS3000C Series allows these tech-
nicians to check the quality of a communications
signal using eye diagrams.
To use an eye diagram to check the quality
of a communications signal:
1. Press the front-panel Autoset button.
2. As desired, adjust the Horizontal Scale to adjust the
width of the eye.
3. Adjust the front-panel Horizontal Delay to view both
the positive and negative transitions at the same time.

20
www.tektronix.com/tds3000TDS3000C Series Oscilloscopes
Make a Quick Pass/Fail Test of a Device-under-test (DUT)
Manufacturing engineers often perform repetitive
tests in which they desire quick pass/fail decisions
on a DUT. The TDS3000C Series offers quick
pass/fail, or limit, tests by comparing active signals
of a DUT with template envelope waveforms of a
known good device. The oscilloscope can be set up
to stop the acquisition, sound a beep, print a hard
copy or save the waveform to disk if any part of the
active waveform strays outside the reference limits.
To create a template for limit testing and
perform a limit test:
1. Press the QuickMenu front panel button.
2. Press the Menu bottom button to select Limit Test.
3. Press the top two side menu buttons to select the
Setup On Violation options.
4. Select the Template Source waveform and the
Template Destination reference location.
5. Set the vertical and horizontal limits of the template
waveform.
6. Store the limit test template.
7. Press Ref and select the specified reference memory
to display the template.
8. Press Control to select On and start the test.
Requires TDS3LIM limit testing module.