Stanford SR844 Lock-In Amplifier (25 kHz to 200 MHz)

Signal Channel:

Voltage input: Single-ended BNC

Input impedance: 50 Ω or 1 MΩ + 30 pF

Damage threshold: ±5 V (DC + AC)

Bandwidth: 25 kHz to 200 MHz

Sensitivity:

<1 MHz: 100 nVrms to 1 Vrms full scale

<50 MHz: 1 µVrms to 1 Vrms full scale

<200 MHz: 10 µVrms to 1 Vrms full scale

Gain accuracy:

<50 MHz: ± 0.25 dB

<200 MHz: ± 0.50 dB

Gain stability: 0.2 %/°C

Reference Channel:

External reference input: 25 kHz to 200 MHz

Impedance: 50 Ω or 10 kΩ + 40 pF

Level: 0.7 Vpp pulse or 0 dBm sine

Pulse width: >2 ns at any frequency

Threshold setting: Automatic, midpoint of waveform

Acquisition time:

<10 s (auto-ranging, any frequency)

<1 s (within same octave)

Internal reference: 25 kHz to 200 MHz

Frequency resolution: 3 digits

Frequency accuracy: ±0.1 in the 3rd digit

Demodulator:

Zero stability: Digital displays have no zero-drift. Analog outputs have <5 ppm/°C drift for all dynamic reserve settings.

Time constants: 100 µs to 30 ks with 6, 12, 18 or 24 dB/octave rolloff

”No Filter” mode: 10 to 20 µs update rate (X and Y)

Harmonic rejection:

Odd harmonics: -9.5 dBc at 3 × ref, -14 dBc at 5 × ref, etc. (20log 1/n where n = 3, 5, 7, 9...)

Even harmonics: <-40 dBc

Sub-harmonics: <-40 dBc

Displays:

Channel 1:

Type: 4½-digit LED with 40-segment bar graph

Quantities: X, R (V or dBm), X-noise, Aux In 1

Channel 2:

Type: 4½-digit LED with 40-segment bar graph

Quantities: Y, Θ, Y-noise (V or dBm), Aux In 2

Channel 1 and Channel 2 Outputs:

Voltage range: ±10 V full scale proportional to X, Y or CH1, CH2 displayed quantity

Update Rate:

X, Y: 48 to 96 kHz

R, Θ, Aux inputs: 12 to 24 kHz

X-noise, Y-noise: 512 Hz

Auxiliary Inputs and Outputs:

Inputs: 2

Type: Differential, 1 MΩ

Range: ±10 V

Resolution: 0.33 mV

Bandwidth: 3 kHz

Outputs: 2

Range: ±10 V

Resolution: 1 mV

General:

Interfaces: IEEE-488.2 and RS-232 interfaces are standard. All instrument functions can be controlled and read through the interfaces.

Power: 70 W, 100/120/220/240 VAC, 50/60 Hz

Dimensions: 17" × 5.25" × 19.5" (WHL)

Weight: 23 lbs.

Datasheet

Manual