Signal Integrity and Protocol Decode Datasheet

TekExpress Automotive Ethernet Signal Separation and PAM3 Analysis

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For Automotive Ethernet designing, testing, and debugging, Tektronix offers the comprehensive PAM3 Signal Analysis, Signal Quality test, and Protocol Decode testing solution.

Key features
  • Signal Separation software: Tektronix Signal Separation software (Patent pending) lets you perform Signal Analysis or Protocol Decode without effecting the ECU system or installing a direct coupler by cutting the Ethernet cable.
  • PAM3 Analysis: You can perform PAM3 Analysis to measure Eye Opening, Eye Mask testing, Jitter Separation, and BER plot in real ECU environment for the Master ECU or Slave ECU.
  • Enhanced Clock Recovery: Software clock recovery offers the industry's most robust clock recovery capability even from heavily impaired signals.

  • Signal Quality Test: You can perform Open Alliance TC8 Signal Quality test with an Eye Diagram instead of a Signal Quality Index (SQI) value. The Eye Diagram in a noise condition provides better insight compared to the SQI value.
  • Protocol Decode: The Tektronix PAM3 solution offers simultaneous Protocol Decode of Master and Slave ECUs, using the Signal Separation technique.
  • Comprehensive Reporting: Automated reporting with Pass/Fail screenshots of the waveforms.

Automotive Ethernet overview

The Autonomous Driving Assistance System (ADAS) and human-to-machine subsystems generate vast amount of data to transport through a vehicle. Requirements for greater integration between vehicle subsystems are driving fundamental architectural changes, moving from simple ring networks to more complex topologies, including gateways connected to an Automotive Ethernet backbone.

Automotive Ethernet is quickly becoming the fastest growing technology for in-vehicle networks.

Automotive Ethernet provides significant advantages including:

  • PAM3 modulation supports high data rates and reliability

  • Unshielded and single twisted-pair cabling lowers cost and weight

  • Full-duplex communication allows devices to send and receive simultaneously on a link

  • Proven IT technology with reliable data throughput for safety critical systems


The integration of Automotive Ethernet technology is placing greater demands on comprehensive design validation to ensure interoperability and reliability between multiple ECUs and devices that will perform reliability in demanding environments. To meet strict compliance tests and have greater confidence in design margins operating under real world conditions, a complete testing solution is a necessity.

Automotive Ethernet and Full Duplex Communication


Automotive Ethernet operates as a full-duplex communication link over a twisted pair cable. The full-duplex communication along with PAM3 signaling adds complexity in validating the ECUs in the real world conditions.

To perform Signal Analysis over the link and Protocol Decode in a real system environment, automobile designers need to look at each link separately which requires the user to separate the signals before performing analysis. Unfortunately, many of the current testing solutions requires breaking the Automotive Ethernet cable to perform the testing. This introduces additional test challenges. The Tektronix PAM3 Signal Analysis application solves these issues with a comprehensive testing solution.

Use Cases


Customer DUT Type Job to be done
PHY Silicon companies Automotive Ethernet PHY Silicon
  • Compliance Test as per Open Alliance
  • Protocol Test at the system level
Automotive T1 companies, Cable manufacturer   ECU
  • Compliance and Interop test as per Open Alliance
  • Signal Quality Test
  • Protocol Test
System: ECU to ECU, ECU to Sensor, Cable
  • System performance under noise
  • Cable selection
Performance Test
  • Performance Test
    • Manufacturing Variation Test
Automotive OEM In-Car Testing  
  • Performance Test
    • Manufacturing Variation Test
  • Performance Test under various scenarios
    • Cracking
    • DC Motor
  • Protocol Test
  • Debug


Signal separation

As Automotive Ethernet is full-duplex communication, both ECUs can send and receive the data simultaneously on the same link. To perform Signal Analysis or Protocol Decode in a real system environment, the traffic of the Master and the Slave ECU needs to be separated.

One approach to separate the full-duplex signal is to use a Directional coupler. This approach requires the user to cut the cables to install the Directional coupler. Using a Directional coupler adds its own Insertion loss and Return loss which can negatively impact the testing results. While it is possible to compensate for the loss at the setup level, the directional coupler approach disturbs the system, making it difficult to know if the errors are introduced by the additional hardware.

To avoid erroneous measurements, Tektronix unique Signal Separation separates the full-duplex signal using the advanced software. The Signal Separation solution accesses the voltage and current waveform from either the Master or Slave Test point, or from both sides simultaneously using the Tektronix proprietary Signal Separation algorithm. This method displays true ECU signals (Master and Slave) without impacting the ECU system.





The Tektronix Signal Separation software can separate full-duplex traffic for testing real ECU test conditions, including different cable lengths and types, different ECUs, ECU-to-Switch conditions, ECU and Protocol Analyzer, different noise conditions, and inside the car with the Automotive Ethernet connectivity.

Refer to the Signal Access section to learn more about how to connect the voltage and current probes for different testing situations.




Full-duplex Signal Separation using software method

Ease of use: It is easy to connect the voltage and current probes without disturbing the cables. You can directly connect probes to the ECU connector. If a fixture is needed to access signals, Tektronix can provide assistance to design a fixture to connect the voltage and current probes.

Automation: The TekExpress Ethernet Signal Separation and PAM3 Analysis software is a completely Automated test solution. Using the Tektronix TekExpress automation platform, its user interface design guides you step-by-step to configure the system and perform analysis.




PAM3 Analysis: The following three levels of PAM3 introduce additional complexity in signaling and place new demands on the test methodology. The PAM3 analysis tool offers several measurement and visualization capabilities to make the task of validating Automotive Ethernet PAM3 designs more efficient.

PAM3 Measurement configuration: The configuration panel within the PAM3 analysis tool let you configure most elements for a PAM3 analysis run. The setup tool includes measurement source selection, clock recovery, and threshold configuration.


Measurement configuration


Clock recovery: The configurable PLL (Phase-Locked Loop) clock recovery function reliably extracts the symbol clock, even with highly impaired signals, and exports the reconstructed clock waveform to a reference channel where it is viewed.





PAM3 measurements: The PAM3 analysis package provides a comprehensive set of measurements that offer greater insight into signal characteristics, speeding up validation or characterization of PAM3 designs with different cable length, noise conditions ECU configurations, and so on.


PAM3 measurements

PAM3 measurements
Measurement group Measurements
Eye diagram Eye Height
Eye Width
Eye Mask
Jitter Random Jitter (DD)
Deterministic Jitter (DD)
Total Jitter @ BER
Timing Rise Time (Symbol 0->1, -1->1 and -1->0)
Fall time (Symbol 0->-1, 1->0 and 1 -> -1)
PAM3 Modulation Linearity

Visualization: A comprehensive set of plots let you visualize the measurement data. The plots provide insight into the signal characteristics and are useful for debugging.

The plot tool set enables interaction with the plots, helping you to focus on an area of interest for closer examination and further analysis.


Ordering Information

Required hardware

5 Series MSO oscilloscope (1 GHz Option 5-BW-1000 or 2 GHz Option 5-BW-2000) or 6 Series MSO oscilloscope with minimum bandwidth of 1 GHz (Option 6-BW-1000, 6-BW-2500, 6-BW-4000, 6-BW-6000, 6-BW-8000)

Option 5-WIN, Opt. 6-WIN or SUP5-WIN, SUP6-WIN (removable SSD with Microsoft Windows 10 operating system)

Required software

Option 5-AUTOEN-SS or 6-AUTOEN-SS (Automotive Ethernet Signal Separation)

Option 5-PAM3 or 6-PAM3 (PAM3 Analysis)

Option 5-DJA or 6-DJA (Advanced Jitter and Eye Analysis)

Option 5-CMAUTOEN or 6-CMAUTOEN (TekExpress 100BASE-T1/1000BASE-T1 Automotive Ethernet Compliance)

Option 5-SRAUTOEN1 or 6-SRAUTOEN1 (100BASE-T1 Protocol Decode)

Recommended options

Option 5-AUTO-BND or 6-AUTO-BND (Automotive Ethernet Compliance, Signal Separation, PAM3 Analysis (requires Option 5-⁠DJA), 100BASE-T1 Serial Decode (bundle option))

Option 5-RL-125M or SUP5-RL-125M (adds 125 M record length)

Option 5-SRAUTO or 6-SRAUTO, SUP5-SRAUTO or SUP6-SRAUTO (adds CAN, CAN FD, LIN, FlexRay Serial Bus Trigger and Decode)

Option 5-SREMBD or 6-SREMBD, SUP5-SREMBD or SUP6-SREMBD (adds I2C, SPI Serial Bus Trigger and Decode)

TDP1500 or TDP3500 differential probe(s), TCP0030A or P6022 current probe(s)
Recommended test fixtures

Contact Tektronix for ECU dependent fixtures

Recommended extras

External PC monitor

USB keyboard

USB mouse

Last Modified: 2019-07-23 05:00:00

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