The Stanford Research Systems SR810 DSP Lock-In Amplifier is a high-performance instrument engineered for precise measurement of small AC signals in noisy environments. It replaces traditional analog demodulators, filters, and amplifiers with digital signal processing technology, delivering superior stability and dynamic reserve exceeding 100 dB drift-free. The SR810 achieves full-scale sensitivity from 2 nV to 1 V continuously variable, with input noise of 6 nV/√Hz at 1 kHz for voltage measurements.
Technical Specifications
Signal Channel
• Voltage inputs: single-ended or differential (A or A-B)
• Current inputs: 10⁶ A/V or 10⁸ A/V gain selection
• Full-scale sensitivity: 2 nV to 1 V (1-2-5-10 sequence)
• Input impedance: 10 MΩ ± 25 pF (voltage); 1 kΩ to virtual ground (current)
• Input noise: 6 nV/√Hz at 1 kHz (voltage); 0.13 pA/√Hz at 1 kHz or 0.013 pA/√Hz at 100 Hz (current)
• Gain accuracy: ±1% (±0.2% typical)
• Line filters: 50/60 Hz notch and 100/120 Hz (2× line) selectable
Reference Channel
• Frequency range: 1 mHz to 102.4 kHz
• Frequency accuracy: 25 ppm + 30 µHz
• Frequency resolution: 4½ digits or 0.1 mHz (whichever is greater)
• Internal reference: 0.004 Vrms to 5 Vrms sine output (2 mV resolution) at 50 Ω impedance
• Reference distortion: -80 dBc (f 10 kHz) at 1 Vrms amplitude
• Phase resolution: 0.01 degrees
• External reference input supported with phase-lock capability
Signal Processing
• Digital signal processing with dynamic reserve > 100 dB (drift-free)
• Selectable time constants from 10 µs to 30 ks
– Key Features
• DSP-based architecture eliminates analog component drift and nonlinearity
• Dual-output reference source (sine and TTL)
• AC/DC coupling selection on voltage inputs
• Programmable notch filters for 50/60 Hz power line rejection
– Typical Applications
Precise signal detection in materials science, optical measurements, semiconductor characterization, and sensitive electronics testing where background noise and interfering signals are present.
