The Keysight (formerly Agilent) N4903B J-BERT is a high-performance serial bit error ratio tester (BERT) and jitter tolerance analyzer. Designed for validating next-generation gigabit serial interfaces, it provides an integrated platform for characterizing receiver performance. The N4903B features comprehensive jitter injection capabilities (including RJ, PJ, SJ, BUJ, and tunable ISI), built-in clock data recovery (CDR), and automated jitter tolerance testing for data rates up to 14.2 Gb/s. It is widely relied upon for compliance testing across industry standards such as PCIe, USB, SATA, and DisplayPort.
Specifications
General
| Parameter | Value |
|---|---|
| Interfaces | GPIB (IEEE 488.2), LAN (10/100/1000Base-T), USB 2.0 |
| Display | Integrated color touchscreen LCD |
Physical
| Parameter | Value |
|---|---|
| Power Supply | 100 - 240 VAC, 50/60 Hz |
| Operating Temperature | 5 to 40 |
General System Specifications
| Parameter | Value |
|---|---|
| Operating Data Rate Range | 150 Mb/s to 7.0 Gb/s, 12.5 Gb/s, or 14.2 Gb/s (option dependent) |
| Number of Channels | 1 (Differential Data Output, Differential Data Input) |
| Supported Data Formats | NRZ |
| PRBS Pattern Lengths | 2^7-1, 2^10-1, 2^11-1, 2^15-1, 2^23-1, 2^31-1 |
| Instrument Architecture | Integrated |
| Operating System | Windows |
Pattern Generator (Data Output)
| Parameter | Value |
|---|---|
| Output Impedance | 50 Ω |
| Error Injection Modes | Single, Fixed Rate |
Error Detector (Data Input)
| Parameter | Value |
|---|---|
| Input Sensitivity | < 50 mVpp (typical) |
| Input Impedance | 50 Ω |
| Clock Data Recovery (CDR) | Built-in, with tunable loop bandwidth (option dependent) |
| Auto-Alignment Capabilities | Automated voltage and phase alignment |
Jitter and Interference Injection
| Parameter | Value |
|---|---|
| Jitter Injection Sources | SJ, RJ, PJ, BUJ, DCD, ISI (configuration/option dependent) |
| Sinusoidal Jitter (SJ) Frequency Range | Up to 1 GHz |
| Inter-Symbol Interference (ISI) Injection | Built-in, tunable (via Option J20) |
| Spread Spectrum Clocking (SSC) | Supported |
Measurement and Analysis Results
| Parameter | Value |
|---|---|
| Automated Jitter Tolerance Testing | Supported (compliant with major serial bus standards) |
| Error Measurement Results | BER, Errored Seconds, Error-Free Seconds, Sync Loss Count |
| Bathtub Curve Analysis | Supported |
| Eye Contour Analysis | Supported |
| Fast Total Jitter (TJ) Measurement | Supported |
Connectivity and Interfaces
| Parameter | Value |
|---|---|
| Trigger Output | Supported |
| Pattern Sync Output | Supported |
Configuration Options
| Parameter | Value |
|---|---|
| Data Rate Configurations | 150 Mb/s to 7 Gb/s (Option C07), 12.5 Gb/s (Option C13), or 14.2 Gb/s (Option C14) |
Jitter Injection
| Parameter | Value |
|---|---|
| Periodic Jitter (PJ) Injection | Two independent PJ sources (with Option J20) |
| Bounded Uncorrelated Jitter (BUJ) Injection | Yes, PRBS generated (with Option J20) |
Interference Injection
| Parameter | Value |
|---|---|
| Sinusoidal Interference (SI) | Common-mode and differential-mode injection (with Option J20) |
Environmental
| Parameter | Value |
|---|---|
| Storage Temperature Range | -40 °C to +70 °C |
| Operating Humidity | 15% to 95% at +40 °C (non-condensing) |
Performance
| Parameter | Value |
|---|---|
| Available Data Rate Options | 7 Gb/s (Option C07), 12.5 Gb/s (Option C13), 14.2 Gb/s (Option C14) |
Inputs & Outputs
| Parameter | Value |
|---|---|
| Data Input/Output Configuration | Differential or single-ended |
Signal Conditioning
| Parameter | Value |
|---|---|
| Pre-emphasis / De-emphasis | Supported via external N4916B De-emphasis Signal Converter |
Applications & Compliance
| Parameter | Value |
|---|---|
| Target Serial Standards (J-Tol) | PCIe, USB, SATA/SAS, DisplayPort, Fibre Channel, QPI, CEI, 10GbE |
Technology
Bit Error Ratio Tester (BERT)
Applications
Receiver Characterization, Jitter Tolerance Testing, Serial Data Compliance (PCIe, USB, SATA)