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?

Gustaaf Sutorius

Application Engineer

Agilent Technologies

[email protected]

#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

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


2. Hot TDR



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



26




27


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


2. Hot TDR



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


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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


2. Hot TDR



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?

measuring “hot tdr” and eye diagrams with an …esd protection inside simple and intuitive...

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