Stanford Research Systems SR570 Low-Noise Current Preamplifier

The Stanford Research Systems SR570 is a low-noise current preamplifier engineered to amplify minute AC currents with exceptional sensitivity across a broad frequency spectrum. It delivers selectable gain from 10³ V/A to 10¹⁰ V/A, input-referred current noise below 1 fA/√Hz at 1 kHz, and adjustable bandwidth via low-pass (1 Hz to 50 kHz) and high-pass (0.01 Hz to 500 Hz) filters. The instrument features switchable input impedance at 1 MΩ or 1 GΩ, programmable input bias current (0 pA, 10 pA, 100 pA, 1 nA), and offset adjustment for DC nulling. Output voltage range reaches ±10 V on a BNC connector. Housed in a 19-inch rack-mountable chassis with front-panel controls for gain, filtering, impedance selection, and bias current configuration, the SR570 serves demanding applications in photodiode detection, cryogenic measurements, materials characterization, and particle beam monitoring.

– Technical Specifications

• Gain: 10³ V/A to 10¹⁰ V/A (continuous adjustment within each range)
• Input-referred voltage noise: < 4 nV/√Hz at 1 kHz
• Input-referred current noise: < 1 fA/√Hz at 1 kHz
• Low-pass filter: 1 Hz to 50 kHz (adjustable)
• High-pass filter: 0.01 Hz to 500 Hz (adjustable)
• Input impedance: 1 MΩ or 1 GΩ (selectable)
• Input bias current: 0 pA, 10 pA, 100 pA, 1 nA (switchable)
• Output voltage range: ±10 V
• Power: 120 VAC, 60 Hz

– Key Features

• BNC connectors for current input and amplified voltage output
• Adjustable input offset voltage and current for DC component nulling
• Front-panel gain selection and continuous adjustment knobs
• Filter setting controls for low-pass and high-pass optimization
• Power and overload indicators
• 19-inch rack-mountable form factor

– Typical Applications

• Photodiode and photomultiplier tube (PMT) signal amplification
• Superconducting device and cryogenic sensor current measurement
• Semiconductor and thin-film electrical characterization
• Ion beam and electron beam detection and quantification
• Spectroscopy signal conditioning

– Compatibility & Integration

The SR570 operates from standard USA mains voltage with internal power supply and integrates into laboratory measurement systems via standard BNC connectors.