Sr850 dsp lock-in amplifier, Specifications – SRS Labs SR850 User Manual
Page 7
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SR850 DSP LOCK-IN AMPLIFIER
1-5
SPECIFICATIONS
SIGNAL CHANNEL
Voltage Inputs
Single-ended (A) or differential (A-B).
Current Input
10
6
or 10
8
Volts/Amp.
Full Scale Sensitivity
2 nV to 1 V in a 1-2-5-10 sequence (expand off).
Input Impedance
Voltage: 10 M
Ω
+25 pF, AC or DC coupled.
Current: 1 k
Ω
to virtual ground.
Gain Accuracy
±1% from 20°C to 30°C (notch filters off), ±0.2% typical.
Input Noise
6 nV/
√
Hz at 1 kHz (typical).
Signal Filters
60 (50) Hz and 120(100) Hz notch filters (Q=4).
CMRR
100 dB at 10 kHz (DC Coupled), decreasing by 6 db/octave above 10 kHz
Dynamic Reserve
Greater than 100 dB (with no signal filters).
Harmonic Distortion
<-90 dB to 10 kHz, <-80 dB to 100 kHz.
REFERENCE CHANNEL
Frequency Range
1 mHz to 102 kHz
Reference Input
TTL (rising or falling edge) or Sine.
Sine input is1 M
Ω
, AC coupled (>1 Hz). 400 mV pk-pk minimum signal.
Phase Resolution
0.001°
Absolute Phase Error
<1°
Relative Phase Error
<0.001°
Orthogonality
90° ± 0.001°
Phase Noise
External synthesized reference: 0.005° rms at 1 kHz, 100 ms, 12 dB/oct.
Internal reference: crystal synthesized, <0.0001° rms at 1 kHz.
Phase Drift
<0.01°/°C below 10 kHz
<0.1°/°C to 100 kHz
Harmonic Detect
Detect at Nxf where N<32767 and Nxf<102 kHz.
Acquisition Time
(2 cycles + 5 ms) or 40 ms, whichever is greater.
DEMODULATOR
Zero Stability
Digital displays have no zero drift on all dynamic reserves.
Analog outputs: <5 ppm/°C for all dynamic reserves.
Time Constants
10 µs to 30 s (reference > 200 Hz). 6, 12, 18, 24 dB/oct rolloff.
up to 30000 s (reference < 200 Hz). 6, 12, 18, 24 dB/oct rolloff.
Synchronous filtering available below 200 Hz.
Harmonic Rejection
-90 dB
INTERNAL OSCILLATOR
Frequency
1 mHz to 102 kHz.
Frequency Accuracy
25 ppm + 30 µHz
Frequency Resolution
5 digits or 0.1 mHz, whichever is greater.
Frequency Sweeps
Linear and Log.
Distortion
f<10 kHz, below -80 dBc. f>10 kHz, below -70 dBc.1 Vrms amplitude.
Output Impedance
50
Ω
Amplitude
4 mVrms to 5 Vrms (into a high impedance load) with 2 mV resolution.
(2 mVrms to 2.5 Vrms into 50
Ω
load).
Amplitude Accuracy
1%
Amplitude Stability
50 ppm/°C
Outputs
Sine output on front panel. TTL sync output on rear panel.
When using an external reference, both outputs are phase locked to the
external reference.