|The SR560 is a high-performance, low-noise preamplifier that is ideal for a wide variety of applications including low-temperature measurements, optical detection, and audio engineering.|
SR560 Low Noise Preamplifier
The SR560 is a high-performance, low-noise preamplifier that is ideal for a wide variety of applications including low-temperature measurements, optical detection, and audio engineering.
The SR560 has a differential front end with 4 nV/√Hz input noise and an input impedance of 100 MΩ. Complete noise figure contours are shown in the graphs below. The SR560's inputs are fully floating (BNC shields are not connected to chassis ground). Both the amplifier ground and the chassis ground are available on the rear panel for flexibility in grounding the instrument. Input offset nulling is accomplished by a front-panel potentiometer, accessible with a small screwdriver.
In addition to the signal inputs, a rear-panel TTL blanking input lets you quickly turn off and on the instrument's gain. This is useful in preventing
Preamplifier Block Diagram
Two insulated output BNC connectors provide 600 Ω and 50 Ω outputs. Both are capable of driving 10 Vpp into their respective loads.
Gains are selectable from 1 to 50,000 in a
The SR560 contains two first-order RC filters whose cutoff frequency and type (HPF or LPF) can be configured from the front panel. Together, the filters can be configured as a 6 or 12 dB/oct rolloff low-pass or high-pass filter, or as a 6 dB/oct rolloff
Three internal, rechargeable, lead-acid batteries provide up to 15 hours of battery powered operation. An internal battery charger automatically charges the batteries when the unit is connected to the line. The charger senses the battery state and adjusts the charging rate accordingly.
No Digital Noise
Short Circuit Input Noise
The microprocessor that runs the SR560 is "asleep" except during the brief interval it takes to change the instrument's setup. This ensures that no digital noise will contaminate low-level analog signals.
The RS-232 interface allows listen-only communication with the SR560 at 9600 baud. Up to four SR560s can be controlled from a single computer, with each SR560 being assigned a unique address. A "Listen" command specifies which SR560 will respond to commands on the