Agilent/Keysight 1158A

The Agilent/Keysight 1158A is a 4 GHz active probe engineered for high-speed digital signal analysis in confined spaces and challenging-to-reach device geometries. It delivers sub-88 ps rise time performance and integrates with the AutoProbe interface for automatic oscilloscope configuration on compatible Infiniium platforms.

Technical Specifications

• Maximum bandwidth: 4 GHz (with 110 Ω resistive signal pin configuration)


• Rise time: 12 Vpp for edges exceeding 3 nsec


• Offset capability: ±15 V


• Thermal drift: < 1.0 mV/°C


• Attenuation: 10:1 Input Capacitance


• 0.8 pF (130 Ω configuration)


• 0.9 pF (110 Ω configuration)


• 1.2 pF (5 cm resistive leads)


• 1.8 pF (10 cm socket-end lead)

Key Features Multiple connector configurations optimize performance across different measurement scenarios. The 110 Ω resistive signal pin achieves full 4 GHz bandwidth with minimal capacitive loading. Lower-bandwidth configurations using extended leads accommodate applications where physical access constraints dictate longer probe paths. Minimal DC resistance (100 kΩ at low frequencies) preserves signal fidelity. Non-resonant input design eliminates ringing artifacts common in passive probes. Vertical offset adjustment via oscilloscope control enables flexible DC biasing.

Typical Applications High-speed digital circuit debugging on densely populated PCBs. Analog signal acquisition on integrated circuits with sub-micron feature spacing. Mixed-signal validation where probe loading must remain below 2 pF. Signal integrity analysis on transmission lines operating above 1 GHz.

Compatibility & Integration AutoProbe interface enables plug-and-play integration with Agilent/Keysight Infiniium Series oscilloscopes, including 54846A Series models 90404A and 90604A. Compatible with InfiniiVision 5000, 6000, and 7000 Series (excluding 6000 Series 100 MHz models). Discontinued June 1, 2014; end of support September 1, 2019.