Paul Capozzoli

Introducing the First & Only Thunderbolt 3 Transmit Compliance Solution

Blog Post created by Paul Capozzoli Employee on Oct 5, 2016

Keysight recently introduced the industry’s first (and only) certified Thunderbolt 3 transmitter compliance application, N6470A


What is Thunderbolt 3?

Thunderbolt is the brand name of a hardware interface that allows the connection of external peripherals to a computer.  Thunderbolt 3 was developed by Intel and was announced in the first half of 2015.  Its claim to fame is speed; two independent 20 Gbps links into one logical 40 Gbps link.  Thunderbolt 3 is a revolutionary I/O technology that supports high resolution displays and high performance data devices through a single compact USB Type-C port.  It sets new standards for speed, flexibility, and simplicity.  Multiple devices can be daisy chained to create a Thunderbolt network.  While Thunderbolt one and two just specified active electrical and also optical cables, version three also supports connecting devices with passive cables at full speed. The Type-C connector brings more speed, more pixels (4K), more power (100 Watts), and more protocols (Thunderbolt, DisplayPort, USB, and PCIe).   From the Intel Thunderbolt website, they depict the following:  

Thunderbolt was developed to simultaneously support the fastest data and most video bandwidth available on a single cable, while also supplying power. The USB group introduced the USB-C connector, which is small, reversible, fast, supplies power, and allows other I/O in addition to USB to run on it, maximizing its potential. So in the biggest advancement since its inception, Thunderbolt 3 brings Thunderbolt to USB-C at 40 Gbps, fulfilling its promise to create one compact port that does it all. As Intel states on their website, Thunderbolt 3 mode is a single cable that provides four times the data and twice the video bandwidth of any other cable, while supplying power. It’s unrivaled for new uses, such as 4K video, single-cable docks with charging, external graphics, and built-in 10 Gigabit Ethernet networking.  Simply put, Thunderbolt 3 delivers the best USB-C.   You can connect two 4K 60 Hz displays with amazing resolution, contrast, and color depth to see your photos, videos, applications, and text with remarkable detail.   Just to give you an idea of the performance, you can transfer a 4K high definition movie in less than 30 seconds. You can connect two 4K displays with nearly 16 million more pixels than an HDTV. The latest MacBook Pro 2016 Includes Thunderbolt 3 with USB-C.  Some other Manufacturers with notebooks and laptops supporting Thunderbolt 3 are HP, Acer, Dell, Alienware, Asus, Lenovo, MSI, and Razer Blade.


Who needs to do Thunderbolt 3 Compliance testing?

Manufacturers of Thunderbolt 3 chip sets, servers, workstations, laptops, gaming PC’s, industrial cameras, high speed PCIe storage, displays, and adapters are required to perform industry standard compliance and validation testing to the industry compliance specification “USB Type-C Thunderbolt Alternate Mode Electrical Host / Device Compliance Test Specification”. Their key issues are ‘how do I ensure the transmitter is in spec?’, ‘how much time will it take to make all the required measurements?’ and ‘how can I make sure my test results are repeatable?’   At 20 Gbps, signals are significantly impaired when conducted electrically over short distances. Analyzing these signals is critical for chip manufacturers characterizing silicon, or a system integrator doing debug, validation, or compliance.

The good news is that Keysight’s high speed Infiniium oscilloscopes are now the only scopes that are currently specified for Transmitter compliance testing.  Here is what this standard specifies for transmit compliance test equipment:


Required Test Equipment Capabilities

  • DC to 21±1GHz, -3db bandwidth or greater
  • 50G sample/sec sampling rate or greater, sampling 2 channels simultaneously
  • Sample memory: 2 channels at 50 M samples per channel or greater
  • 1st and 2nd order CDR capability
  • Equalization for USB3.1 model capability


Recommended Test Equipment:


Our N6470A Thunderbolt 3 electrical transmit compliance test application

The N6470A Thunderbolt 3 electrical test software gives you a fast and easy way to verify and debug your Thunderbolt designs for both silicon validation as well as end products like storage devices or motherboards. The Thunderbolt 3 electrical test software allows you to automatically execute Thunderbolt 3 electrical transmitter tests and displays the results in a flexible report format.

In addition to the measurement data, the report provides a margin analysis that shows how closely your device passed or failed each test. The N6470A Thunderbolt 3 electrical test software covers the prescribed test methods and parameters required for Thunderbolt electrical certification testing. This produces results that are consistent with those obtained during official certification at approved test labs and informational testing at plugfests.  In addition to automatic setup and execution of the transmitter tests, the N6470A Thunderbolt 3 electrical test software also provides automatic setup and control of the crosstalk generator source, a required condition for electrical testing during official certification tests.

N6470A Automation

  • Test setup wizard guides you through test selection, configuration, connection, execution, and results reporting
  • Measurement connection setups are displayed
  • Automated setup and control of the required crosstalk source(s), and the oscilloscope setup is automatically configured for each test
  • Test results report documents test configuration, measurements made, pass/fail status, margin analysis, and waveforms

N6470A Extensibility

  • Run tests with live or saved waveforms for easy regression testing if specification requirements change
  • Create and fully integrate custom tests, configuration variables, and connection instructions
  • Insert external application calls into the run sequence, such as MATLAB scripts or your device controller
  • Configure additional external instruments used in your test suite


Keysight provides a simple, repeatable automated and unattended calibration and test execution using automation software for transmit test.  All Type-C PHY standards are addressed by Keysight’s Test platform; Thunderbolt 3, USB 3.1, and DisplayPort. Our solution helps you with pre-compliance testing with jitter, rise time and voltage measurements. For a complete presentation please see this URL: Thunderbolt 3 over Type C - Overcoming Test Challenges.


The N6470A Thunderbolt 3 Compliance Test Software for Infiniium oscilloscopes is priced at $16,000* for a fixed license and $24,000* for a transportable license.

The full N6470A compliance test suite



N6470A Real-Time Eye diagram for 10 waveforms with margin analysis




*All prices are in USD and are subject to change