Keysight / Agilent / HP 1159A Differential Probe

The Keysight 1159A is an active differential probe designed for precision measurement of high-speed differential signals across DC to 1 GHz. FET-buffered inputs in the probe head deliver low noise and minimal input capacitance (1.5 pF), reducing loading effects on the circuit under test. The 1:1 attenuation and rise time under 350 ps enable accurate acquisition of fast transients. User-selectable offset (±1.5 V) enhances measurement flexibility across signal types. With CMRR greater than 19 dB at 500 MHz, the probe effectively rejects common-mode noise to isolate differential signals.

– Technical Specifications

• Bandwidth: DC to 1 GHz (−3 dB)
• Attenuation: 1:1
• Rise Time (probe only): 19 dB at 500 MHz
• Input Impedance: 1 MΩ resistance, 1.5 pF capacitance
• Offset Range: ±1.5 V
• Operating Temperature: 0 to 50 °C

– Key Features

• FET-buffered inputs ensure high input impedance and low noise performance
• Small form factor facilitates probing of dense PCB layouts
• Standard 0.025″ (0.635 mm) square pin receptacles for connection to surface mount and through-hole components
• Rugged construction with ESD tolerance
• Selectable offset capability for versatile signal measurement
• Single-ended measurement capability via high-impedance FET probe operation

– Typical Applications

• Disk drive read channel measurements
• Differential LAN signal acquisition
• High-speed video signal analysis
• Digital systems where ground loops must be avoided

– Compatibility & Integration

• AutoProbe Interface compatible for automatic oscilloscope setup
• Plug-on attenuators and AC coupling accessories available to extend application range
• Interconnect accessories supplied for various component types