Lock-In Preamplifier SR552 — BJT input preamplifier · 1.4 nV/√Hz input noise · BJT input, 100 kΩ input impedance · Gain of 10, 20, 50 or 100 · Single-ended and differential inputs · AC coupled input · Powered by SRS lock-in amplifiers The SR552 Voltage Preamplifier is designed to work with SRS lock-in amplifiers, providing gain where it is needed most—right at the experiment. The preamplifier minimizes noise and pickup in the connecting lines and can reduce measurement time in noise-limited experiments. The SR552 has a bipolar front-end design (100 kΩ impedance, 1.4 nV/√Hz noise). Power and control signals are brought from the lock-in by a 9-pin cable (included). The SR552 may also be operated independently by applying appropriate power supply voltages (±20 VDC, +5 VDC). Source Resistance Input impedance 100 kΩ + 25 pF Inputs Single-ended or differential Maximum input 70 mVrms for overload 50 VDC, 20 VAC damage threshold Noise (typ.) 1.4 nV/√Hz at 1 kHz 1.6 nV/√Hz at 100 Hz 2.5 nV/√Hz at 10 Hz Coupling AC (0.016 Hz) CMRR (1 V input) 100 dB at 100 Hz Gain 10, 20, 50, 100 (Automatically set by SR510 or SR530 lock-in) Full-scale input 10 nV to 200 mV Gain accuracy 2 % (2 Hz to 100 kHz) Gain stability 200 ppm/°C Outputs A (signal, 600 Ω, single-ended) B (shielded ground) Maximum output 10 Vpp Power Supplied by SR510, SR530, SR810, SR830, SR850 or SR124 via control cable Mechanical 3.0" × 1.3" × 5.1" (WHD) Weight 1 lbs. Warranty One year parts and labor on defects in materials and workmanship Ordering Information Stanford Research Systems Lock-in preamplifier