HP / Agilent 5315B 100 MHz Universal Counter

The HP/Agilent 5315B is a 100 MHz universal counter delivering frequency, period, time interval, ratio, and totalize measurements with 8-digit LED display resolution. Its metal cabinet construction provides enhanced electromagnetic shielding suitable for laboratory and rack-mounted test systems. Expandable to 1 GHz with optional Channel C, the 5315B combines flexible input coupling, variable trigger control, and multiple time base options for precision frequency measurement from 0.1 Hz to 100 MHz.

Technical Specifications Measurement Capabilities

Frequency: 0.1 Hz to 100 MHz; up to 1 GHz with Option 003 (Channel C)

Period: 10 ns to 10 s

Time Interval: Single-shot (100 ns resolution), Averaging (10 ps resolution), and Delay modes

Ratio: Two-input frequency ratio measurement

Totalize: 0 to 100 MHz, manual or external gating via Input A or Input B Input Channels A & B

Frequency Range: DC-coupled 0 Hz to 100 MHz; AC-coupled 30 Hz to 100 MHz

Sensitivity: 10 mV rms to 10 MHz; 25 mV rms to 100 MHz; 75 mV peak-to-peak pulse (5 ns minimum width); continuously variable to 500 mV rms

Dynamic Range: 30 mV to 5 V peak-to-peak (0–10 MHz); 75 mV to 5 V peak-to-peak (10–100 MHz)

Signal Operating Range: +2.5 Vdc to −2.5 Vdc

Input Impedance: 1 MΩ nominal shunted by <40 pF

Attenuator: X1 or X20 nominal

Trigger Level: Variable +2.5 Vdc to −2.5 Vdc with independent slope selection

Filter: 100 kHz low-pass, switchable on Channel A Channel C (Option 003)

Frequency: 50 MHz to 1 GHz at 25 mV sensitivity to 100 MHz Time Base Options

Standard: 10 MHz, <3 parts in 10⁷/month aging, ±5 parts in 10⁶ temperature stability (0–50 °C)

Option 001 (TCXO): 10 MHz, <1 part in 10⁷/month aging, ±1 part in 10⁹ temperature stability (0–40 °C)

Option 004 (Oven): 10 MHz, <3 parts in 10⁸/month aging, ±2 parts in 10⁸ temperature stability (0–50 °C)

Key Features

Metal cabinet for RFI immunity and mechanical durability

Reciprocal counting at low frequencies for enhanced resolution

AC/DC coupling selection per input

Selectable attenuator for extended dynamic range

Multiple time base stability grades

Typical Applications

Frequency and period measurement in RF/microwave development

Precision time interval analysis and jitter characterization

Signal ratio and event counting in automated test systems

Laboratory calibration and standards verification

Compatibility & Integration Rack-mountable metal construction integrates into benchtop and ATE environments with minimal EMI considerations.