Measuring “Hot TDR” and Eye Diagrams with an …ESD protection inside Simple and Intuitive...
Transcript of Measuring “Hot TDR” and Eye Diagrams with an …ESD protection inside Simple and Intuitive...
Measuring “Hot TDR” and Eye Diagrams
with an Vector Network Analyzer?
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Gustaaf Sutorius
Application Engineer
Agilent Technologies
#TDR fit in Typical Digital Development Process
• Accurate Models• Accurate
Simulations
SystemDesign
InterconnectDesign
Active SignalAnalysis
ComplianceTest
• Accurate Design Analysis
• Test & Analysis Capability
• Increased Team Effectiveness
• Measurement Automation• Hardware &
Software Correlation
Capability• Measurement
Automation
Automation• Test & Analysis
Capability
Measure
Agenda
1. RF Network Analyzer with TDR & EYE diagrams
2. Hot TDR
3. Compliance Support
4. Summary and Q&A4. Summary and Q&A
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TDR in time domain
ZL
Ei Er
OSCILLOSCOPE
STEP GENERATOR
TRANSMISSION SYSTEM UNDER TEST
Ei
Er
T
Oscilloscope display when Er ≠ 0
Typical Step: 200 mV, 250 kHz square wavewith 35 ps rise time
Scope Displaying impedance in the Time Domain:54754A TDR provides “Instantaneous Impedance”
Typical TDR result
• A: 50 Ohm cable
• B: Launch to microstrip
• C: 50 Ohm microstripA B
C
DE
F
• C: 50 Ohm microstrip
• D: 75 Ohm microstrip
• E: 50 Ohm microstrip
• F: “open” circuit
With option 202 TDR results from 54754A now also available in S-parameters format (S11, S21)
Eye Masks & TDR with an Network Analyzer?
The ENA Option TDR is an application software embedded on the ENA, which provides an one-box solution for high speed serial interconnect analysis.
What is ENA E5071C Option TDR?
Frequency DomainTime Domain
3 Breakthroughsfor Signal Integrity Design and Verification
Eye Diagram
ESD protection inside
Simple and Intuitive Operation
ESD Robustness
Fast and Accurate Measurements
What is ENA E5071C Option TDR?Modes of Operation
TDR/TDT mode
� 1/2/4 port TDR/TDT and S-parameters (SE and BAL)
� Setup Wizard
� Functional enhancements
� Zooming, horizontal autoscale, additional marker functions, …
� Performance enhancementsPerformance enhancements
�Z Peeling (lossless), robust DC extrapolation methods, …
Eye/Mask Mode (ENA measures Transmission)
Simulated Eye diagram & Eye mask functionIn the oscilloscope, an eye diagram is often used to analyze signal quality. You can diagnose problems, such as attenuation, noise, jitter, and dispersion that arise or characterize specific parts of the system with one display.The E5071C option TDR provides simulated eye diagram analysis capability, eliminating the need for a hardware pulse pattern generator. The virtual bit pattern generator is used to define a virtual bit pattern. The defined bit pattern is then convolved with the device impulse response to create an extremely accurate measurement based eye diagram.
E5071C already has high performance TDR functionality.(Option 010)
But…Since the U/I is based on the traditional soft-key architecture, high speed digital signal integrity engineers accustomed to using oscilloscopes seem to find the U/I unfamiliar and not so easy to use.
What about E5071C Option 010? Not Good Enough?
(from E5071C brochure)
Therefore…To fill this gap, a new simple and intuitivesimple and intuitivesimple and intuitivesimple and intuitive U/I was developed to vastly improve the usability of TDR/TDT measurements.
In addition…TDR/TDT specific features are added to improve transmission line impedance measurements. (gating for example)
ENA #010 OperationOption 010 vs Option TDR
Instrument Setup: Measurement Parameters:•Nop=1601•Port Extension (P1~P4)•Display allocation:
Reflection Parameters
Tdd11, Tdd22Format RealZreflection ON
Transmission Parameters
Time Domain Frequency Domain
Tdd21, Tdd12Format RealZreflection ON
Sdd11, Sdd22Format LogMag
Sdd21, Sdd12Format LogMag
Port1(ENA)
Port2(ENA)
Port3(ENA)
Port4(ENA)
E5071-26588 demo board
ENA #010 Operation: many steps neededOption 010 vs Option TDR
> 40 steps !!
* Refer to appendix of E5071C Option TDR demo guide for step-by-step setup procedure.
ENA #TDR Operation: Just 4 Steps neededOption 010 vs Option TDR
Procedure:
•Start Option TDR ApplicationPress [Analysis] > TDR
•Follow Setup Wizard Instructions[Step 1] Select DUT Type[Step 2] Deskew
4 steps !!
[Step 2] Deskew[Step 3] Set DUT length[Step 4] Set rise time
ENA #TDR Operation:“Default” (for scope users) and “Advanced”
Advanced Features•Full access to ENA firmware functions and capabilities.To enter the Advanced mode, press the advanced mode checkbox under the Settings tab on the Option TDR user interface.
Default Features•Limited access to ENA firmware functions and capabilities
Limited access to front panel hard-keys
Sufficient for majority of
digital usersOperation is possible by front panel keys, soft-key menus, and
Option TDR U/I.
Operation by soft-key menu is not allowed
Operation is done through Option TDR U/I
# TDR has 2 modes: TDR/TDT and Eye/Mask
delta time(skew)
Zoom
Marker Lines
x-scaleannotation
Txy
horizontal autoscale
TDR/TDT Mode: Reflection Eye/Mask Mode: Transmission
(skew)annotation
selectable rise timedefinition(10-90%, 20-80%)
scale control usingscroll mouse
autoscale
peeling
trace copy& coupling set bit pattern
set mask
•The default lowpass step mode is equivalent to the TDR scope response
Time Domain View & Frequency Domain View
Time Domain Response Frequency Domain Response
•Sdd11 results shows that signals are reflected across a wide frequency range.
High frequency components have a larger impact on high speed systems.
Which section of the DUT is causing the most high frequencyreflections?
Touch the board to observe the corresponding point change on the time domain response in real time.
Gating in Time Domain:Observe Frequency Response at specific physical loc ation
3
4
5
1
2
lowpassstepbandpass
impulse
• Data analysis using bandpass impulse mode
Enhance “sensitivity” by using “Bandpass Impulse”
Time Domain Response(lowpass step)
Time Domain Response(bandpass impulse)
A large peak at the input connector is measured in the bandpass impulse response, whereas no significant peak appears in the lowpass step response.
The low frequency reflections are mainly from the stepped impedance and the high frequency reflections are mainly
reflections from stepped impedance
Gating + bandpass impulse mode :specific physical locations have different Frequenc y responses!
Which section of the DUT is causing the most reflections?
frequency reflections are mainly from the connector.
To reduce the reflection of high frequency components, the connector match must be improved.
reflections from connector
Actual Measurements at Amstelveen Office
Connector launch: good SWR at low freq, worse at hi gh freq
Note: good SWR = low return loss = little or no re flections
First 50 to 25 ohm step on PCB stripline: Good SWR at high freq, worse SWR at low freq
What about the distance resolution?
E5071C 20GHz 14GHz 8.5GHz 6.5GHz 4.5GHz 3GHz
Rise Time (LP Step)
Spec. min(10-90%) 22.3 ps 31.9 ps 52.5 ps 68.6 ps 99.1 ps 149. ps
Response Typ. min
response resolution = step rise time * speed of light * velocity of propagation
Time domain response resolution:•the ability to resolve two closely spaced responses, or a measure of how close two responses can be to each other and still be distinguished from each other.•Response resolution depends upon whether it is a reflection or a transmission measurement, and the relative propagation velocity of the signal path.•For responses of equal amplitude, the response resolution is equal to the step rise time.
ResponseResolution
Typ. min@ LP Step mode, reflection meas, in air (εr = 1)
3.3 mm 4.8 mm 7.9 mm 10.3 mm 14.9 mm 22.4 mm
Typ. min@ LP Step mode, reflection meas, in FR4 (εr = 4.9)
1.5 mm 2.2 mm 3.5 mm 4.6 mm 6.7 mm 10.1 mm
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[Example]Time domain response resolution for responses of equal amplitude, using 20 GHz model, reflection measurement, in FR4 (εr=4.9, vf=1/√εr=0.45)
•response resolution (transmission) = (22.3 ps) x (3.0e8 m/s) x (0.45) = 3.0 mm•response resolution (reflection) = (22.3 ps) x (3.0e8 m/s) x (0.45) / 2 = 1.5 mm
Time domain
Frequency domain
EYE Diagram
Eye mask editor
Eye Diagram
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Eye diagram Virtual bitpattern generator
Automated eye diagram measurement results
Eye mask test
Agenda
1. RF Network Analyzer with TDR & EYE diagrams
2. Hot TDR
3. Compliance Support
4. Summary and Q&A4. Summary and Q&A
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Hot TDR Measurements
April 2, 2011Confidentiality Label
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2007 HDMI Developers Conference, “HDMI and HDMI 1.3 — A Technical Overview”, Silicon Image http://www.hdmi.org/devcon/presentations/2007_DevCon_SiliconImage_English.pdf
Hot TDR Measurements
April 2, 2011Confidentiality Label
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2007 HDMI Developers Conference, “HDMI and HDMI 1.3 — A Technical Overview”, Silicon Image http://www.hdmi.org/devcon/presentations/2007_DevCon_SiliconImage_English.pdf
Hot TDR Measurements
April 2, 2011Confidentiality Label
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2007 HDMI Developers Conference, “HDMI and HDMI 1.3 — A Technical Overview”, Silicon Image http://www.hdmi.org/devcon/presentations/2007_DevCon_SiliconImage_English.pdf
t
Advantages of ENA Option TDR for Hot TDRFast and Accurate Measurements
Wideband Receiver
•wideband receiver captures all of the signal energy from the transmitter
For Hot TDR measurements, data signals from the transmitter cause measurement error...
Narrowband Receiver
•narrowband receiver minimizes the effects of the data signal from the transmitter
ENA Option TDRTDR Scopes
tt
t
t
t
Tx Tx
freqfc
Wideband Receiver
time
To obtain a stable waveform, extensive averaging is necessary.
fcfreq
Narrowband Receiver
time
In many cases, averaging is not necessary to obtain a stable waveform.
Agenda
1. RF Network Analyzer with TDR & EYE diagrams
2. Hot TDR
3. Compliance Support
4. Summary and Q&A4. Summary and Q&A
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ENA Option TDR
Measurement Correlation between TDR ENA and TDR sc ope Eye Diagram
ENA Option TDR N4903B + 86100C
Simulated Eye
Live Eye
•DUT: differential PCB trace•PRBS (2^7-1) @ 1Gbps
NOTE: For further details, refer to Application Note, “Correlation between TDR oscilloscope and VNA generated time domain waveform” (5990-5238EN)
Both ENA #TDR and 86100C #TDR Comply To SATA
SATA Hot TDR Measurement Results 160 Gbyte hard-disc
April 2, 2011Confidentiality Label
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•E5071C Method of Implementation (MOI) for USB3.0 and DisplayPort Cable Compliance Test
• VBA program and operation guide also available for USB3.0, HDMI, and DisplayPortCable Compliance Test[Example] USB3.0 Cable measurement using the VBA program
Compliance Support
Agilent E5071C is certified equipment for , , and Cable/Connector Compliance Tests
Refer to following links for further information:• DisplyPort http://www.home.agilent.com/upload/cmc_upload/All/E5071C_DP_CableTest_MOI.pdf• USB3.0 http://www.home.agilent.com/upload/cmc_upload/All/E5071C_USB30_CableTest_MOI_100.pdf
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Compliance Support
SuperSpeed USB Developers Conference (Taiwan, April 1-2, 2010)http://www.usb.org/developers/ssusb
ENA Option TDR introduced as
recommended solution for CabCon compliance test
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Agenda
1. RF Network Analyzer with TDR & EYE diagrams
2. Hot TDR
3. Compliance Support
4. Summary and Q&A4. Summary and Q&A
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Summary
Time domain Frequency domain Eye diagram
The Agilent ENA Option TDR application…
•Provides one-box solution for high speed serial interconnect analysis
•Brings three breakthroughs for signal integrity design and verification
Fast & AccurateMeasurements
Simple & IntuitiveOperation ESD Robustness
Additional Resources
ENA Option TDR Reference Material
•Technical Overview (5990-5237EN)
•Configuration Guide (5989-5480EN)
•Application Notes:
•Correlation between TDR oscilloscope and VNA generated time domain waveform (5990-5238EN)
www.agilent.com/find/ena-tdr
(5990-5238EN)
•Comparison of Measurement Performance between Vector Network Analyzer and TDR Oscilloscope (5990-5446EN)
•Accuracy Verification of Agilent’s ENA Option TDR Time Domain Measurement using a NIST Traceable Standard (5990-5728EN)
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Questions?