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7265 Dual Phase DSP Lock-in Amplifier

7265 Lock-in Amplifier
Model 7265

The SIGNAL RECOVERY model 7265 uses digital signal processing (DSP) technology to extend the operating capabilities of the lock-in amplifier to provide the researcher with a very versatile unit suitable both for measurement and control of experiments.

Operating over a frequency range of 1 mHz to 250 kHz, the model 7265 offers full-scale voltage sensitivities down to 2 nV and current sensitivities to 2 fA. The instrument has a choice of operating modes, signal recovery or vector voltmeter, for optimum measurement accuracy under different conditions, and the use of DSP techniques ensures exceptional performance.

The 7265 is capable of measuring the in-phase and quadrature components, vector magnitude, phase angle and noise of the input signal.

Virtual Reference
Under suitable conditions, this mode allows measurements to be made in the absence of a reference signal

Dual Reference
In this mode the instrument can make simultaneous measurements on two signals at different reference frequencies, which is ideal, for example, for use in source compensated optical experiments

Spectral Display
This allows the spectrum of the signals present at the input to be calculated and displayed, which can help when choosing the reference frequency

Transient Recorder
In this mode, the auxiliary ADC inputs can be used as a 40 kSa/s (25 μs/point) transient recorder, with the captured transient being displayed graphically

Frequency Response
This built-in experiment allows the internal oscillator frequency to be swept between preset frequencies, while simultaneously measuring the input signal magnitude and phase. The mode is ideal for determining the frequency and phase response of external networks.

Harmonic Analysis
Most lock-in amplifiers will measure signals at the applied reference frequency or its second harmonic. In the 7265, operation is possible at harmonics up the 65,536th, and in Dual Harmonic mode, simultaneous measurements can be made on two harmonics.

  • Documents +

  • Specifications +

    Dual-phase DSP lock-in amplifier operating over a reference frequency range of 0.001 Hz to 250 kHz.

    Wide range of extended measuring modes and auxiliary inputs and outputs.

    User-upgradeable firmware.
    Measurements Modes
    The instrument can simultaneously show any four of these outputs on the front panel display:
    X In-phase
    Y Quadrature
    R Magnitude
    ø Phase Angle
    Harmonic nF, n≤ 65, 536
    Dual Harmonic
    Simultaneously measures the signal at
    two different harmonics F1 and F2of the
    reference frequency
    Dual Reference
    Simultaneously measures the signal at
    two different reference frequencies, F1
    F2 where F1 is the external and F2the
    internal reference
    Frequency Range for Dual Harmonic and Dual Reference Modes
    F1 and F2 ≤ 20 kHz
    Virtual Reference
    Locks to and detects a signal without a
    reference (100 Hz ≤ F ≤ 250 kHz)
    Measures noise in a given bandwidth
    centered at the reference frequency F
    Spectral Display
    Gives a visual indication of the spectral
    power distribution of the input signal in a
    user-selected frequency range lying
    between 1 Hz and 60 kHz. Note that
    although the display is calibrated in
    terms of frequency, it is not calibrated
    for amplitude. Hence it is only intended
    to assist in choosing the optimum
    reference frequency
    240 x 64 pixel cold fluorescent backlit
    LCD panel giving digital, analog bar-
    graph and graphical indication of
    measured signals. Menu system with
    dynamic key function allocation. On-
    screen context sensitive help
    Signal Channel
    Voltage Input

    A only, -B only or Differential (A-B)
    Full-scale Sensitivity 2 nV to 1 V in a 1-2-5 sequence
    Max. Dynamic Reserve > 100 dB
    FET Input
    Bipolar Input

    10 MΩ // 30 pF
    10 kΩ // 30 pF
    Maximum Safe Input 20 V pk-pk
    Voltage Noise
    FET Input
    Bipolar Input

    5 nV/√Hz @ 1 kHz
    2 nV/√Hz @ 1 khZ
    C.M.R.R. > 100 dB @ 1 kHz
    Frequency Response 0.001 Hz to 250 kHz
    Gain Accuracy ±0.2% typ
    Distortion -90 dB THD (60 dB AC gain, 1 khZ)
    Line Filter attenuates 50, 60, 100, 120 Hz
    Grounding BNC shields can be grounded or floated via 1 kΩ to ground
    Current Input
    Mode Low Noise or Wide Bandwidth
    Full-scale Sensitivity
    Low Noise
    Wide Bandwidth

    2fA to 10 nA in a 1-2-5 sequence
    2 fA to 1 µA in a 1-2-5 sequence
    Max. Dynamic Reserve > 100 dB
    Frequency Response (-3 dB)
    Low Noise
    Wide Bandwidth
    > 500 Hz
    ≥ 50 kHz
    Low Noise
    Wide Bandwidth

    < 2.5 kΩ ! 100 Hz
    <250 Ω @ 1 kHz
    Low Noise
    Wide Bandwidth

    13 fA/√Hz @ 500 Hz
    1.3 pA/√Hz @ 1 kHz
    Gain Accuracy ± 0.6% typ, midband
    Line Filter attenuates 50, 60, 100, 120 Hz
    Grounding BNC shield can be grounded or floated via 1 kΩ to ground-
    Reference Channel
    TTL input (rear panel)
    Frequency Range

    0.001 Hz to 250 kHz
    Analog Input (front panel)
    Sinusoidal input
    Frequency Range
    Squarewave input
    Frequency Range

    1 MΩ // 30 pF

    1.0 V rms*
    0.3 Hz to 250 kHz

    250 mV rms*
    2 Hz to 250 kHz
    *Note: Lower levels can be used with the analog input at the expense of increased phase errors
    Phase Set Resolution 0.001º increments
    Phase Noise at 100 ms TC, 12 dB/octave slope
    Internal Reference
    External Reference

    < 0.001º rms
    <0.01º rms @ 1 kHz
    Orthogonality 90º ±0.001º
    Acquistion Time
    Internal Reference

    instantaneous acquisition
    External Reference 2 cycles + 50 ms
    Reference Frequency Meter Resolution 1 ppm or 1 mHz, whichever is the greater
    Demodulator and Output Processing
    Output Zero Stability
    Digital Outputs
    Analog Outputs

    No zero drift on all settings
    No zero drift on all settings
    < 5 ppm/ºC
    Harmonic Rejection -90 dB
    Output Filters
    X, Y and R outputs only
    Time Constant

    Slope (roll-off)
    All outputs
    Time Constant

    10 µs to 640 µs in a binary sequence

    6 dB/octave

    5 ms to 100 ks in a 1-2-5 sequence
    6, 12, 18 and 24 dB/octave
    Synchronous Filter Available for F < 20 Hz
    Offset Auto and Manual on X and/or Y: ±300% full-scale
    Absolute Phase Measurement Accuracy ≤0.01º
    Setting Resolution
    1 mHz ≤ F ≤ 900 Hz
    F . 900 Hz
    Absolute Accuracy

    0.001 Hz to 250 kHz

    1 mHz
    4 mHz
    ± 50 ppm
    Distortion (THD) -80 dB @ 1 kHz and 100 mV rms
    Amplitude (rms)
    1µV to 4 mV
    4 mV to 500 mV
    500 mV to 2 V
    2 V to 5 V
    > 1 mV
    100 µV - 1 mV

    1 µV to 5 V rms
    125 µV
    500 µV
    1.25 mV

    ±0.3%, F ≤ 60 kHz, ±0.5%, F > 60 kHz
    ±1%,F ≤ 60 kHz, ±3%, F > 60 kHz
    50 ppm/ºC
    Output Impedance
    Amplitude Sweep
    Output Range
    Step Rate

    0.001 to 5.000 V rms
    20 Hz maximum (50 ms/step)
    Frequency Sweep
    Output Range
    Step Rate

    0.001 Hz to 250 kHz
    Linear or Logarithmic
    20 Hz maximum (50 ms/step)
    Auxiliary Inputs
    ADC 1 & 2
    Maximum input
    Input Impedance
    Smple Rate
    ADC 1 only
    ADC 1 and 2
    Trigger Mode
    Trigger Input

    ±10 V
    1 mV
    ±20 mV
    1 MΩ // 30 pF

    40 kHz max.
    17.8 kHz max.
    Internal, External or burst
    TTL compatible
    ADC 3
    Maximum input
    Input Impedance
    Sampling Time

    ±10 V
    12 to 20 bit, depending on sampling time
    1 MΩ // 30 pF
    10 ms to 2 s, variable
    Fast Outputs

    Update Rate

    X and Y or X and Mag
    ±2.5 V full-scale; linear to ±300% full-scale

    1 kΩ
    166 kHz
    Main Analog (CH1 and CH2) Outputs


    Update Rate

    X, Y, R, ø, Noise, Ratio, Log Ratio and User Equations 1 & 2.
    ±10.0 V full-scale; linear to ±120% full-scale

    1 kΩ
    200 Hz
    Signal Monitor

    ±10 V FS
    1 kΩ
    Auxiliary D/A Outputs 1, 2, 3 and 4
    Maximum Output
    Output Impedance

    ±10 V
    1 mV
    ±10 mV
    1 kΩ
    8-bit Digital Output Port
    8 TTL-compatible lines that can be independently
    set high or low to activate exteranl equipment
    Reference Output

    0 to 5 V rectangluar wave
    Power - Low Voltage ±15 V at 100 mA rear panel 5-pin 180º DIN connector for powering SIGNAL RECOVERY preamplifiers
    Data Storage Buffer

    Max Storage Rate

    From LIA
    From ADC1

    32k x 16-bit data points, may be organized as 1x32k, 2x16k, 3x10.6k, 4x8k, etc.

    up to 1000 16-bit values per second
    up to 40,000 16-bit values per second
    User Settings
    Up to 8 complete instrument settings can
    be saved or recalled from non-volatile
    RS232 and GPIB (IEEE-488). A second
    RS232 port is provided to allow "daisy-
    chain" connection and control of up to 16
    compatible instruments from a single
    RS232 computer port
    Power Requirements

    110/120/220/240 VAC
    50/60 Hz
    40 VA max
    With feet
    Without feet

    13¼" (350 mm)
    16½" (415 mm)

    4¼" (105 mm)
    3½" (90 mm)
    Weight 18 lb (8.1 kg)
  • Options +

    Item Model Number
    Rack Mount K02003
  • Software +

    Item Model Number
    Acquire Software
    The software includes a powerful plotting engine that lets you show data just as you want it using a variety of line styles, allows data export to both text and CSV files, offers comprehensive clipboard support, and includes a context-sensitive help system
    Active X Control SRINSTCOMMS