SR554 – Transformer preamplifier


  • Transformer preamplifier


SR554 – Transformer preamplifier


The 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 wide range of low-noise applications. It is the ideal preamplifier for low-temperature synchronous detection applications where isolation between the experimental sample and the lock-in amplifier is critical.


• Transformer-coupled input
• 0.1 nV/√Hz input noise
• 0.1 Hz to 40 kHz bandwidth
• Gain of 100 or 500
• Single-ended and differential inputs
• >40 dB isolation (DC to 500 MHz)
• Powered by SRS lock-ins


Technical Specifications

Mode: Single-ended or differential
Noise: 0.1 nV/?Hz
Source impedance: 0.05 ? to 1 k? (recommended)
CMRR: >120 dB below 1 kHz
Common mode range: Primary can float to ?100 VDC
Gain: 100? (Transformer only)
500? (Transformer and buffer)
Max frequency response: 0.1 Hz to 40 kHz
Isolation: >40 dB, DC to 500 MHz
Output: Single-ended or differential
Maximum output: 100 Vpp (Transformer only)
20 Vpp (Transformer and buffer)
Output impedance: >5 k? (Transformer only)
<1 ? (Transformer and buffer)
Dimensions and weight: 3.75″” ? 3.0″” ? 7.5″” (WHL), 4 lbs.
Power: Supplied by SRS lock-ins. Ext. ?20 VDC supplies can also power the SR554.
Warranty: One year parts and labor on defects in materials and workmanship