Keysight (Agilent) N4874A Pattern Generator Module

The Keysight N4874A is a pattern generator module designed for testing high-speed digital interfaces and devices within the ParBERT family. This VXI-based generator produces differential and single-ended signals across data rates from 620 Mb/s to 7 Gb/s, supporting pseudo-random word sequences, standard PRBS patterns up to 2³¹-1, and memory-based patterns up to 64 Mb. The module delivers output amplitudes from 0.7 Vpp to 7.8 Vpp with 5 mV resolution, fast transition times below 20 ps, and typical jitter under 9 ps pp across a jitter modulation bandwidth of DC to 1 GHz.

Engineered for R&D and manufacturing environments, the N4874A characterizes emerging backplane, memory interface, and serial bus applications requiring precise signal generation and validation up to 6.4 Gb/s. Operation requires the E4809A Central Clock module as a companion instrument.

Technical Specifications

• Data Rate Range: 620 Mb/s to 7 Gb/s


• Output Amplitude: 0.7 Vpp to 7.8 Vpp


• Output Amplitude Resolution: 5 mV


• Transition Times (20% – 80%): < 20 ps


• Jitter (typical): < 9 ps pp


• Jitter Modulation Bandwidth: DC to 1 GHz


• Module Width: 1 VXI slot


• Pattern Types: Pseudo-Random Word Sequences (PRWS), PRBS up to 2³¹-1, memory-based patterns up to 64 Mb


• Signal Configuration: Differential and single-ended

Key Features

• Fast sub-20 ps transition times enable high-fidelity waveform reproduction


• Low jitter performance (< 9 ps pp typical) supports accurate timing margin analysis


• Multiple pattern generation modes accommodate custom and standard test sequences


• Configurable output amplitude from 0.7 Vpp to 7.8 Vpp in 5 mV steps


• Modular VXI architecture integrates with system-level test benches

Typical Applications

• High-speed communication port and chip characterization


• Serial interface validation and stress testing


• Backplane and memory interface qualification


• Digital system design validation through 6.4 Gb/s

Compatibility & Integration The N4874A requires the E4809A Central Clock module for operation. System integration with power supplies, parametric measurement units, and oscilloscopes is supported via GPIB, LAN, and VXI interfaces using Keysight 81200 plug-and-play drivers. Note: This product is obsolete. The M8030A Multi-Channel BERT is the recommended replacement.