J-BERT N4903B High-performance Serial BERT. The only complete jitter tolerance test – now for next generation of forwarded and embedded clock designs such as QPI, PCIe(TM), DisplayPort, SATA, USB, FB-DIMM, Fibre Channel, 10GbE


  • Data rates 150 Mb/s to 7 Gb/s or to 12.5 Gb/s pattern generator and error detector. Option to extended data rate to 14.2 Gb/s for pattern generator.
  • >0.5 UI calibrated, compliant and integrated jitter injection: RJ, RJ-LF, RJ-HF, PJ1, PJ2, SJ, BUJ, ISI, sinusoidal interference, triangular and arbitrary SSC and residual SSC
  • Excellent signal performance and sensitivity
  • Built-in clock data recovery with tunable and compliant loop bandwidth
  • Half-rate clocking with variable duty cycle for forwarded clocked devices
  • Measures BER, BERT Scan, TJ with RJ/DJ separation, eye diagram, eye mask, BER contour, automated jitter tolerance, pattern capture, frame error rate (FER), or symbol error rate (SER) coded and retimed data streams
  • Two adjustable data outputs with independent PRBS and pattern with 120 block pattern sequencer
  • All options are retrofittable and upgrade from N4903A possible

The J-BERT N4903B high-performance serial BERT provides the most complete jitter tolerance test for embedded and forward clocked devices.

It is the ideal choice for R&D and validation teams characterizing and stressing chips and transceiver modules that have serial I/O ports up to 7 Gb/s, 12.5Gb/s or 14.2 Gb/s. It can characterize a receiver’s jitter tolerance and is designed to prove compliance to today’s most popular serial bus standards, such as:

  • PCI Express® See Measurement Solution Example: PCIe 3.0 Receiver Test
  • DisplayPort
  • USB SuperSpeed
  • Fibre Channel
  • QPI
  • Memory buses, such as fully buffered DIMM2
  • Backplanes, such as CEI
  • 10 GbE/ XAUI
Jitter setup screen of J-BERT N4903B Automated jitter tolerance characterization
Jitter setup screen of J-BERT N4903B Automated jitter tolerance characterization
Quick eye diagram and mask test BERT scan with RJ/DJ separation
Quick eye digram and mask test

J-BERT N4903B key benefits:

Accurate characterization is achieved with clean signals from the pattern generator, which features exceptionally low jitter and extremely fast transition times. Built-in and calibrated jitter source allow accurate jitter tolerance testing of receivers.

Test set-up is simplified significantly, because the J-BERT N4903B is designed to match serial bus standards optimally with its differential I/Os, variable voltage levels on most outputs, built-in jitter and ISI, pattern sequencer, reference clock outputs, tunable CDR, pattern capture and bit recovery mode to analyze clock-less and non-deterministic patterns.SER/FER analysis allows jitter tolerance testing of devices using retimed loopback. A second data output with independent pattern memory and PRBS can be used as an aggressor channel for crosstalk tests, or when adding channels externally for OOB timing tests or emulation of 3-level signals or signal de-emphasis.

Faster test execution is possible with J-BERT’s automated jitter tolerance tests fast total jitter measurements.

The J-BERT N4903B is a long-term investment which is configurable for today’s test and budget requirements but also allows upgrades from the N4903A model, and later retrofit of all options and full speed when test needs change.

J-BERT awards: J-BERT's technology leadership has been honored by our customers and key technical publications with several product awards. Read more

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