SR551 – High impedance preamplifier


  • High impedance preamplifier


SR551 – High impedance preamplifier


The SR551 High Impedance Preamplifier works with SRS lock-in amplifiers to measure voltages from sources with moderate to high source impedance. The preamplifier is designed for source impedances of up to gigaohms with little error from resistive loading, due to its exceptionally high 1 TΩ input impedance. The SR551 operates with a fixed votage gain of ×10, amplifying signals from DC to 1 MHz.


• >1 TΩ input impedance
• Gain of ×10
• Single-ended and differential inputs
• 1 MHz bandwidth
• 12 nV/√Hz at 1 kHz voltage noise
• Powered by SRS lock-in amplifiers


Technical Specifications

Input impedance: >1 T?
Inputs: Single-ended or differential
Input range: -4 V to +4 V
Gain: ?10
Gain accuracy: ?0.5 % at 1 kHz
Gain stability: ?25 ppm/?C (0?C to 40?C)
Bandwidth: 1 MHz (-3 dB)
Input bias current: <1 pA Input voltage noise: 12 nV/?Hz at 1 kHz (typ.) Input current noise: 0.6 fA/?Hz at 1 kHz CMRR: >90 dB at 1 kHz
Input offset voltage: <500 ?V
Vos drift (typ.): 3 ?V/?C (0?C to 40?C)
Output: 8 Vp (max), balanced differential, 10 mA (max), 50 ?
Power: Supplied by SRS Lock-Im Amplifier “”Preamp Power”” via control cable
Dimensions: 3.0″” ? 1.3″” ? 5.1″” (WHL)
Weight: 1 lbs.
Temperature range: 0?C to 40?C
Warranty: One year parts and labor on defects in materials and workmanship