HP / Agilent 3780A PATTERN GENERATOR

The HP/Agilent 3780A is a portable pattern generator and error detector engineered for validation of digital transmission systems. Operating across bit rates from 1 kb/s to 50 Mb/s, it performs closed-loop binary error detection, code error analysis for AMI/HDB3/HDB2 violations, and supports optional B6ZS/B3ZS coding. The instrument generates pseudorandom binary sequences (PRBS) and user-defined word patterns, with zero substitution capability for timing recovery characterization.

Technical Specifications

Bit Rate Range: 1 kb/s to 50 Mb/s

Binary Error Detection: Closed-loop bit-by-bit detection on any pattern generated by the instrument (excluding added zeros or alternating words)

Code Error Detection: Violations of AMI, HDB3, or HDB2 coding rules; optional AMI, B6ZS, or B3ZS support

Pattern Generation: PRBS sequences, user-defined WORD generation, zero substitution

Clock Sources: Internal crystal clocks with clock recovery; external clock input 1 kHz to 50 MHz; three internal crystal options (1.544, 6.312, 3.152 MHz with Option 102)

Clock Offset: ±50 ppm range (except Option 099)

Data Interfaces: Binary clock and data; ternary coded data (RZ AMI or coded)

Data Output Formats: NRZ or RZ; binary or ternary coding (HDB3/HDB2 or B6ZS/B3ZS)

Clock Output: 75 Ω nominal to ground; 3 V ±0.3 V pk-pk; transition time < 4 ns

Data Output Impedance: 75 Ω nominal to ground

Receiver Equalization: Automatic at 2 Mb/s, 8 Mb/s, and 34 Mb/s

Error Display: COUNT or BER over selectable gating periods; LED readout

Result Logging: External printer output with graphical presentation

Frequency Offset Measurement: Available at standard PCM/TDM transmission rates

Key Features

Automatic pattern recognition and synchronization for performance validation

Dual interface support: binary clock/data and ternary coded configurations

Selectable gating periods for BER and error count analysis

Multiple crystal frequency options via plug-in modules

Frequency offset generation and measurement capability

Typical Applications Validation of digital transmission equipment, regenerator timing recovery analysis, systematic error detection through zero substitution, BER characterization across PCM/TDM networks, codec performance evaluation.

Compatibility & Integration Available with Option 001, 002, 099, 100, 101, and 102 for customized clock frequencies and codec variants.