The Keysight N2791A is a 25 MHz high-voltage differential probe that enables floating measurements on earth-grounded oscilloscopes without requiring one measurement point to be at ground potential. This capability is essential in power electronics, motor drives, and automotive electronics applications where high common-mode voltages exist. The probe’s high input impedance (8 MΩ) and low input capacitance (8 pF) minimize circuit loading while delivering accurate differential signal acquisition.
Technical Specifications
Bandwidth & Timing
• Bandwidth: ≥25 MHz
• Rise time (calculated): ≤14 ns
Measurement Capability
• Attenuation ratio: User-selectable 10:1 or 100:1
• Maximum differential operating voltage: ±700 V at 100:1 attenuation; ±70 V at 10:1
• Maximum common-mode input voltage: 700 V
• Maximum working voltage (safety rated): 1000 Vrms CAT II between input leads and earth ground
• Differential voltage measurement: Up to 1,400 VDC + peak AC with CMRR >50 dB at 1 MHz
• Input impedance: 8 MΩ // 8 pF
• Over-range indicator alerts when probe input exceeds dynamic range
Power & Interface
• Power: 4× AA batteries (included) or USB host port via supplied power cable
• Output connector: BNC (compatible with any 1 MΩ oscilloscope input)
• AutoProbe interface compatible with Keysight instruments supporting 1 MΩ input
Physical & Operating Conditions
• Cable length: 70 cm differential cable set
• Operating temperature: −10 to +50 °C
• Included accessories: 2 hook clips, 2 alligator clips, USB power cord, 4 AA batteries, manual
– Key Features
• Eliminates the requirement for earth-grounded reference points in differential measurements
• Selectable attenuation allows optimization for different voltage ranges and resolution requirements
• High CMRR (>50 dB at 1 MHz) rejects common-mode noise effectively
• Over-range indicator prevents invalid measurements
• Dual power options (battery or USB) provide field and lab flexibility
– Typical Applications
• Power supply and power electronics measurements
• Motor drive signal analysis
• Automotive electronics floating-point measurements
• High-voltage differential signal acquisition
– Compatibility & Integration
The N2791A connects to any standard oscilloscope with a 1 MΩ BNC input. Keysight AutoProbe-compatible instruments receive power directly from the probe interface, eliminating battery dependence in automated test environments.
