sr555-exo.

sr555The SR555 is a low-noise, hh-bandwidth, fixed-gain current (trans-impedance) amplifier desned to work with SRS lock-in amplifiers. Current amplifiers provide gain closeThe SR554 is a low-noise, transformer-coupled preamplifier optimized for source impedances between 0.05 Ω and 1 kΩ. With an input noise of only 0.1 nV√Hz, the SR554 can be used in a