Using a BERT for 100 Gb/s-per-lane receiver calibration and conformance testing
400G / 800G electrical receiver conformance testing requires the application of a stressed signal, simulating the worst-case scenario from a compliant transmitter and channel. The receiver must effectively equalize and capture the signal, ensuring a bit error ratio below specified limits. Complicating the process for 100 Gb/s link receivers are the lower noise thresholds of 56 Gbaud PAM4 signals and forward error correction (FEC), which require additional tuning and testing. IEEE 802.3ck and OIF-CEI-5.0 define conformance testing standards for 100 Gb/s receivers used in 400G and 800G Ethernet networks.
Electrical receiver conformance testing begins with precise calibration of the stressed signal and system. Performance validation includes interference tolerance and jitter tolerance tests, ensuring 400G / 800G receiver conformance for all possible deployment scenarios. Chip-to-module interface testing uses the stressed-eye method, with separate calibrations for host and module inputs. For chip-to-chip, backplane, or cable interfaces, the conformance test involves tuning the link channel operating margin by means of broadband noise injection. The test setup requires a bit error ratio tester (BERT) with PAM4 pattern generation and a high-bandwidth, low-noise oscilloscope to calibrate the receiver and stress signal.
400G / 800G electrical receiver conformance test solution
Conformance testing for 100 Gb/s receivers involves applying a stressed signal to simulate worst-case scenarios, requiring precise calibration and testing for interference and jitter tolerance. The Keysight 400G / 800G electrical receiver conformance test solution helps simplify physical layer conformance testing. It includes a 120 Gbaud BERT with high signal integrity performance and automated receiver test software. The software helps developers navigate complex compliance test requirements for the various links and automates testing to ensure repeatable, reliable results. The solution also includes a high-bandwidth, low noise Keysight Infiniium UXR-B Series oscilloscope and PAM4 analysis, jitter analysis, and signal integrity software to calibrate the receiver and FEC algorithm.
How to Test 400G / 800G Electrical Receiver Conformance
M8091CKCA Receiver Conformance Test Application for IEEE 802.3ck
Designed to assist and simplify the stress signal calibration used for testing the inputs of IEEE 802.3ck Draft 3.3 chip-to-chip (C2C) and chip-to-module (C2M) electrical interfaces using Keysight M8040A 64Gbaud Higher Performance BERT or an M8050A 120Gbd High-Performance BERT together with Keysight Digital Communication Analyzer (DCA) Oscilloscope or Infiniium UXR real-time Oscilloscope.
How to Test 400G / 800G Electrical Receiver Conformance
M8050A 120 Gbaud High-Performance BERT
The Keysight M8050A high-performance bit error ratio tester (BERT) enables accurate characterization of receivers used in next-generation data center networks and server interfaces. With uncompromised signal integrity, support for NRZ, PAM4, PAM6, and PAM8 signals, and data rates up to 120 Gbaud, the flexible architecture of the M8050A supports 1.6T pathfinding as well as other leading-edge technologies.
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