HP / Agilent 5328B 100 MHz Universal Counter

The HP/Agilent 5328B is a 100 MHz universal counter engineered for precise frequency, period, time interval, and ratio measurements in laboratory and production test environments. This instrument delivers 8-digit resolution on direct frequency counts and supports multiple measurement modes with configurable trigger levels and attenuation settings. The 5328B integrates into automated test systems and accepts input signals from 25 mVrms across its measurement channels, with dual-channel capability for ratio and time interval averaging operations.

Technical Specifications Frequency Measurement

Range: 0 to 100 MHz

Resolution: Up to 8 digits/s (direct count)

Sensitivity: 25 mVrms to 40 MHz; 50 mVrms from 40 to 100 MHz

Attenuators: X1, X10 switch selectable Period Measurement

Range: 100 ns to 10 seconds

Resolution: 10 ns

Period Average Resolution: 1 fs Time Interval Measurement

Resolution: 10 ns

Time Interval Averaging Resolution: 10 ps

Average Range: 0.1 ns to 1 second

Minimum Dead Time: 40 ns Ratio Measurement

Channel A: 0 to 10 MHz

Channel B: 0 to 100 MHz Totalize

Range: 0 to 10¹² counts Input Characteristics

Channel A Sensitivity: 25 mVrms to 100 Vrms

Channel B Sensitivity: 25 mVrms to 30 Vrms

Trigger Level Range: −5 V to +5 V

Trigger Level Programmability: 10 mV steps (x1); 100 mV steps (x10)

Trigger Level Accuracy (Remote, x1): ±35 mV Time Base

Standard Crystal: 10 MHz, <3×10⁻⁷/month aging, <2.5×10⁻⁵ temperature stability (0–50°C)

Optional Oven Crystal: 10 MHz, <5×10⁻⁹/day aging, <1×10⁻¹⁰ rms/s short-term stability, 20-minute warm-up

Timebase Accuracy & Stability: ±1 ppm Optional DVM (Option 021)

Range: ±10 V, ±100 V, ±1000 V DC and Autorange

Input Impedance: 10 MΩ nominal (floating pair)

Maximum Input: ±1100 V (Hi to Low); ±500 V (Low to Chassis)

Sensitivity: 10 µV to 100 mV depending on measurement window 1300 MHz C-Channel (Option 031)

Frequency Range: 90 MHz to 1300 MHz

Sensitivity: 20 mVrms (−21 dBm)

Maximum Input: 5 Vrms, ±5 Vdc

Key Features

Multi-channel measurement with independent trigger controls

Programmable attenuation and trigger level adjustment via 10 mV or 100 mV steps

Dual time base options: standard crystal for general use or oven oscillator for precision applications

Optional C-channel extends capability to 1.3 GHz for RF counting

Optional DVM provides DC voltage measurement to ±1100 V

High-resolution time interval averaging to 10 ps

Period averaging achieves 1 fs resolution

Typical Applications

Frequency and period verification of oscillators and timing circuits

Time interval and jitter measurement in digital systems

Ratio measurements for frequency divider validation

Event counting and totalization in production test

High-stability frequency measurement with optional oven timebase

Compatibility & Integration The 5328B interfaces with automated test systems through remote control of trigger levels and measurement modes. Modular options allow field configuration: the DVM option (021) adds DC voltage measurement capability; the C-channel option (031) extends frequency measurement to 1300 MHz. Both channels support floating input pairs with independent sensitivity and trigger settings.