BERT instrumentation extended for 400 GbE

May 23, 2016 // By Graham Prophet
Keysight Technologies has added a M8040A high-performance BERT (bit-error-rate tester) for testing PAM-4 and NRZ devices that operate up to 64 GBaud. Engineers in validation labs and R&D who characterize receivers on the physical layer for the next generation of data centre interconnects will benefit, Keysight says, from simplified test setups and repeatable and accurate results.

Higher transmission rates, more transmission lanes and new multi-level data formats like PAM-4 address the increased transmission bandwidth demand for the next generation data center interconnects. The latest revisions of IEEE 802.3 bs and OIF CEI-56G implementation agreements define PAM-4 and NRZ interfaces for electrical chip-to-chip, chip-to-module, backplane connections and optical interfaces for up to 400 Gbit/sec bandwidth. R&D and validation labs who need to characterize receivers for data centre interconnects with PAM-4 or NRZ data rates up to 64 GBaud are facing new test challenges, such as tighter timing margins, channel loss, non-linearity, level interference and crosstalk effects—making test efficiency and accuracy essential.


The new M8040A is the latest member of the modular AXIe based M8000 series of BER test solutions. It is a highly integrated BERT that supports PAM-4 signals up to 64 GBaud and NRZ signals up to 64 Gbit/sec. The pattern generator module provides built-in de-emphasis, jitter injection and an optional second channel. Engineers and designers can select PAM-4 and NRZ in the user interface, eliminating the need for external combiners, cabling and deskew to provide PAM-4 signals. For best signal quality, remote heads reduce the distance to the device under test. The analyzer module provides true PAM-4 error analysis in real-time for long PRBS and QPRBS patterns. This allows proofing even low bit error ratios and symbol error ratios with the required confidence. Users can control the M8040A from a graphical and remote control interface.