SR570 – Low noise current preamplifier


  • Low noise current preamplifier


SR570 – Low noise current preamplifier


The SR570 is a low-noise current preamplifier capable of current gains as large as 1 pA/V. High gain and bandwidth, low noise, and many convenient features make the SR570 ideal for a variety of photonic, low temperature and other measurements..


• 5 fA/√Hz input noise
• 1 MHz maximum bandwidth
• 1 pA/V maximum gain
• Adjustable bias voltage
• Two configurable signal filters
• Variable input offset current
• Line or battery operation
• RS-232 interface


Technical Specifications

Inputs: Virtual null or user-set bias (?5 V)
Input offset: ?1 pA to ?1 mA adjustable DC offset current
Maximum input: ?5 mA
Noise: See graphs
Sensitivity: 1 pA/V to 1 mA/V in 1-2-5 sequence (vernier adj. in 0.5 % steps)
Frequency response: ?0.5 dB to 1 MHz. Adjustable front-panel frequency response compensation for source capacitance.
Grounding: Amplifier ground is fully floating. Amplifier and chassis ground are available at rear panel. Input ground can float up to ?40 V.

Signal filters: 2 configurable (low-pass or high-pass) 6 dB/oct rolloff filters. -3 dB points are settable in a 1-3-10 sequence from 0.03 Hz to 1 MHz.
Gain allocation:
Low noise: Gain is allocated to the front end for best noise performance.
High bandwidth: Front-end gain is reduced for optimum frequency response.
Low drift: Low bias current amplifier is used for reduced drift at high sensitivity.
Filter reset: Long time constant filters may be reset with front-panel button.
Gain accuracy: ?(0.5 % of output + 10 mV) @ 25?C
DC drift: see table below
Maximum output: ?5 V into a high impedance load

External blanking: TTL input sets gain to zero
External toggle: TTL input inverts gain polarity
Rear panel biasing: ?12 VDC @ 200 mA, referenced to amplifier ground
Computer interface: RS-232, 9600 baud, receive only
Power: 100/120/220/240 VAC, 6 watts charged, 30 watts while charging. Internal batteries provide 15 hours of operation between charges. Batteries are charged while connected to the line.
Dimensions: 8.3″” ? 3.5″” ? 13.0″” (WHL)
Weight: 15 lbs. (batteries installed)
Warranty: One year parts and labor on defects in materials and workmanship