SSI OE1022 Digital Lock-In Amplifier 102kHz

Input Signal Channel

The low-noise analog front-end amplifier in the OE1022 lock-in amplifier handles both differential and single-ended signals, with an equivalent input noise of just 5 nV/√Hz. The channel offers a 10 MΩ input impedance and can detect input signal levels from 1 nV to 1 V at full-scale output. The OE1022 also supports input current measurement, with a front-end variable current gain of 106 or 108 V/A.

Reference Signal Channel

The OE1022 digital lock-in amplifier can operate in either internal or external reference mode. In internal reference mode, the instrument's high-precision oscillator and direct digital synthesis algorithm generate the sine wave used to multiply the input signal, and the internal reference is virtually immune to phase noise. Digital phase-shifting technology gives the internal reference a phase resolution of 0.001°. Internal reference mode operates over a frequency range of 1 mHz to 102 kHz. In external reference mode, either a sine wave or TTL logic levels can serve as the external reference. The rising or falling edge of the external reference triggers the internal phase-locked loop (PLL) to lock.

Display

The OE1022 features a 5.6-inch TFT color display with 640×480 resolution as its main screen. Measured data such as X, Y, R, and θ can be displayed simultaneously as numeric values, bar graphs, XY plots, and polar plots.

Simultaneous Multi-Harmonic Measurement

A conventional lock-in amplifier can measure only the fundamental or a single harmonic component at any one time. When both amplitude and phase of multiple frequency components are needed simultaneously, traditional lock-in amplifiers fall short. The digital section of the OE1022 combines FPGA and ARM technology to deliver higher processing bandwidth and a more flexible digital architecture, with digital processing accuracy up to 48 bits. It can measure harmonics at three frequencies simultaneously, making one OE1022 equivalent to three conventional lock-in amplifiers. The highest harmonic signal that can be detected is the 32,767th order of the fundamental, provided the maximum harmonic frequency does not exceed the instrument's 102 kHz operating frequency. 

PC Software Operation

The internal RS232-to-USB interface enables users to fully exploit all OE1022 measurement functions from a host computer, including setting appropriate instrument control parameters and reading measured data. The instrument comes with a free LabVIEW program, making the OE1022 easy to integrate into complex scientific experiments. In the LabVIEW interface, users can view all control commands and the instrument's responses.

Signal channels
        Voltage input mode                Single-ended or differential input
        Full-scale sensitivity                1 nV to 1 V, in 1-2-5 multiplier sequence steps
        Current input gain                106 or 108  V/A
        Input impedance
                Voltage                          10 MΩ//25 pF, AC or DC coupling
                Current                          1 kΩ to virtual ground
        Common-mode rejection ratio                     >100 dB to 10 kHz, decreasing at 6 dB/oct
        Dynamic reserve                         >120 dB
        Gain accuracy                         0.2% standard, 1% maximum
        Voltage noise
                at 997 Hz                 5 nV/√ Hz
        Current noise
                At 97 Hz                   15 fA/√ Hz
                at 997 Hz                 13 fA/√ Hz
        Line frequency filter                     50 Hz and 100 Hz
        Input shield grounding                BNC (A/I, B) shields can be directly grounded or connected to floating ground via a 10 kΩ resistor

Reference channel
        Input
                Frequency range                 1 mHz to 102 kHz
                Reference input                 Square wave or sine wave
                Input impedance                 1 MΩ
                Square-wave reference level         VIH>3V，VIL<0.5V
                Sine reference signal         >1 Hz
                                                    > 400 mVpp
        Phase
                Resolution                      0.001°
                Absolute phase error        <1°
                Relative phase error        <0.001°
                Orthogonality
                        Internal reference         At 1 kHz: <0.0001°rms
                        External reference         At 1 kHz: 0.005°rms (time constant 100 ms, 12 dB/oct)
                Temperature drift
                        Below 10 kHz     <0.01°/℃
                        Above 10 kHz     <0.1°/℃

        Harmonic detection                         2F, 3F, …nF up to 102 kHz (n<32,767)

        Acquisition time

                Internal reference                 Immediate acquisition

                External reference                (2 cycles + 5 ms) or 40 ms

Demodulator

        Stability

                Digital output                 No zero drift for all settings

                Display                          No zero drift for all settings

                Analog output                 All dynamic reserve settings less than 5 ppm/℃

        Harmonic suppression                         -90 dB

        Time constant                         10 us to 3 ks (<200 Hz). 6, 12, 18, 24 dB/oct rolloff

                                                    10 us to 30 s (>200 Hz). 6, 12, 18, 24 dB/oct steep roll-off

        Synchronous filter                     Below 200 Hz with 18, 24 dB/oct steep roll-off enabled

Signal generator

        Frequency

                Range                          1 mHz to 102 kHz

                Accuracy                          2 ppm+10 uHz

                Resolution                      1 mHz

        Distortion                                 -80 dBc(f<10 kHz)，-70 dBc(f>10 kHz)

        Sine amplitude                         0.001 Vrms to 5 Vrms (resolution 1 mVrms)

                Error                          0.5% typical (f<10 kHz), 1% maximum

                Temperature stability             50 ppm/℃

        Sine output                         Sine signal, output impedance 50 Ω

        TTL sync output                  5V TTL/CMOS level, output impedance 200 Ω

Display

        Display                                  5.6-inch, 640×480 TFT color LCD screen

        Screen format                         Single-channel or dual-channel display

        Displayed value                             Each channel can display X, Y, R, and θ values

        Display type                         Digital display plot, bar graph, XY coordinate plot, and polar coordinate plot

        Color style                         Yellow, green

Auxiliary inputs and outputs

        CH 1 and CH 2

                Function                          Outputs X, Y, R, θ and harmonics

                Amplitude                          ±10V

                Drive current                 ±30mA max

        AUX Inputs

                Function                          4-channel input

                Amplitude                          ±10 V, 1 mV resolution

                Impedance                          1 MΩ

        AUX Outputs

                Features                          4-channel output

                Amplitude                          ±10 V, 1 mV resolution

                Drive current                 ±25 mA max

        Trigger Input

                Function                          TTL external trigger for data storage

        Monitor Output

                Features                          Analog output of signal amplifier

                Drive current                 ±40mA max

Communication interface

        RS-232 to USB               RS-232 to USB 2.0 interface for controlling and reading instrument parameters and data

        IEEE-488 interface (optional accessory)

Others

        Power requirements

                Voltage                          220~240 V AC

                Frequency                          50 Hz

                Power                          Standard 30 W, maximum 40 W

        Power line noise rejection                70 dB@1MHz

        Weight                                  11 KG

        Dimensions

                宽                                448 mm

                Depth

                        Including handle          513 mm

                        Excluding handle      470 mm

                高

                        Including feet          148 mm

                        Excluding feet      133 mm

Scanning microscope            AFM, STM, SPM

Materials science                Carrier mobility, carrier density, Hall effect, ultrasonic materials

Transport measurement                Conductance measurement, impedance measurement

Noise characterization                Noise density, cross-correlation measurement

Optical experiments                Spectral analysis, spectral measurement, THz measurement, TDLAS

Sensor measurement            Gyroscopes, photoelectric sensors, resonators, accelerometers

Magnetic Sensing                SQUIDs, NV centers, atomic magnetometers, VSM

Biomedical                Microfluidics