7280 Wide Bandwidth DSP Lock-in Amplifier

7280 Lock-in Amplifier
Model 7280 

The model 7280 DSP Lock-in Amplifier is the widest frequency band offered by Signal Recovery. The 7280 offers direct digital demodulation over an operating frequency range from 0.5 Hz extending up to 2.0 MHz.  The instrument has output filter time constants down to 1 µs and a main ADC sampling rate of 7.5 MHz it is ideal for recovering fast changing signals. The 7280 works in the traditional audio frequency band unlike other high frequency lock-ins.

The front panel offers a large easy to read display used both to show the instrument's outputs and for adjusting its controls via a series of menus. Controls are set by a combination of the use of the keys surrounding the display and the keypad, while four cursor-movement keys simplify use of the graphic display menus.

The 7280 includes the extended operating modes like dual reference, dual harmonic and virtual reference, as well as the spectral display mode used to aid reference frequency selection. It also includes GPIB and RS232 interfaces for remote computer control and a range of auxiliary analog and digital inputs and outputs. Software support is available in the form of a LabVIEW driver supporting all instrument functions, and the Acquire™ data acquisition software. The driver and a demonstration version of the software, DemoAcquire, are available for download from this site.
  • Documents +

  • Specifications +


    Signal Channel
    Voltage Input
    Modes A only, -B only or Differential (A-B)
    Full-scale Sensitivity
    0.5 Hz ≤ F ≤ 250 kHz 10 nV to 1 V in a 1-2-5 sequence
    250 kHz < F ≤ 2.0 MHz 100 nV to 1 V in a 1-2-5 sequence
    Max. Dynamic Reserve > 100 dB
    Impedance 100 MΩ // 25 pF
    Maximum Safe Input 20 V pk-pk
    Voltage Noise 5 nV/√Hz @ 1 kHz
    C.M.R.R. > 100 dB @ 1 kHz
    Frequency Response 0.5 Hz to 2.0 MHz
    Gain Accuracy ±0.3% typ, ±0.6% max. (full bandwidth)
    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, Normal or Wide Bandwidth
    Full-scale Sensitivity
    Low Noise 10 fA to 10 nA in a 1-2-5 sequence
    Normal 10 fA to 1 µA in a 1-2-5 sequence
    Wide Bandwidth
    F ≤ 250 kHz 1 pA to 100 µA in a 1-2-5 sequence
    F > 250 kHz 10 pA to 100 µA in a 1-2-5 sequence
    Max. Dynamic Reserve > 100 dB
    Frequency Response (-3 dB):
    Low Noise ≥ 500 Hz
    Normal ≥ 50 kHz
    Wide Bandwidth ≥ 1 MHz
    Impedance
    Low Noise < 2.5 kΩ @ 100 Hz
    Normal < 250 Ω @ 1 kHz
    Wide Bandwidth < 25 Ω @ 10 kHz
    Noise
    Low Noise 13 fA/√Hz @ 500 Hz
    Normal 130 fA/√Hz @ 1 kHz
    Wide Bandwidth 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
    Frequency Range 0.5 Hz to 2.0 MHz
    Analog Input
    Impedance 1 MΩ // 30 pF
    Sinusoidal Input Level 1.0 V rms*
    Frequency Range 0.5 Hz to 2.0 MHz
    Squarewave Input Level 250 mV rms
    Frequency Range 2 Hz to 2 MHz
    *Note: Lower levels can be used with the analog input at the expense of increased phase errors
    Phase Set Resolution 0.001° increments
    Phase Noise at 100 ms TC, 12 dB/octave slope:
    Internal Reference < 0.0001° rms
    External Reference < 0.01° rms @ 1 kHz
    Orthogonality 90° ± 0.0001°
    Acquisition 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 Filters
    X, Y and R outputs only
    Time Constant 1 µs to 1 ms in a 1-2-5 sequence, and 4 ms
    Slope (roll-off) 6 and 12 dB/octave
    All outputs
    Time Constant 500 µs to 100 ks in a 1-2-5 sequence
    Slope 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 ≤ 0.01°
    Oscillator
    Frequency
    Range 0.5 Hz to 2.0 MHz
    Setting Resolution 1 mHz
    Absolute Accuracy ± 50 ppm
    Distortion (THD) -80 dB @ 1 kHz and 100 mV rms
    Amplitude (rms)
    Range 1 mV to 1 V
    Setting Resolution 1 mV
    Accuracy ±0.2%
    Stability 50 ppm/°C
    Output Impedance 50 Ω
    Sweep
    Amplitude Sweep
    Output Range 0.000 to 1.000 V rms
    Law Linear
    Step Rate 20 Hz maximum (50 ms/step)
    Frequency Sweep
    Output Range 0.5 Hz to 2.0 MHz
    Law Linear or Logarithmic
    Step Rate 1 kHz maximum (1 ms/step) @ output time constant settings of 500 µs or longer; 140 ms/point otherwise
    Outputs
    Main Analog (CH1 and CH2) Outputs:
    Function X, Y, R, Θ, Noise, Ratio, Log Ratio and User Equations 1 & 2.
    Amplitude ±2.5 V full-scale; linear to ±300% full-scale
    Impedance 1 kΩ
    Update Rate
    X, Y or R @ TC £ 4 ms 7.5 MHz
    All outputs @ TC ³ 500 µs 1 kHz
    Reference Output
    Waveform 0 to 3 V rectangular wave, active in External Reference Mode only
    Impedance TTL-compatible
    Power - Low Voltage ±15 V at 100 mA rear panel 5-pin 180° DIN connector for powering SIGNAL RECOVERY preamplifiers
    General
    Power Requirements
    Voltage 110/120/220/240 VAC
    Frequency 50/60 Hz
    Power 200 VA max
    Dimensions
    Width 17¼" (435 mm)
    Depth 19" (485 mm)
    Height
    With feet 6" (150 mm)
    Without feet 5¼" (130mm)
    Weight 25.4 lb (11.5 kg)
  • Options +


    Item Model Number
    Extend Dual Reference Upper Frequency-
    Extends dual reference upper frequency limit to 800kHz
    /99
    Extend Dual Reference Upper Frequency-
    Extends dual reference upper frequency limit to 2MHz
    /98
    Rack Mount K02004
  • 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
    Acquire
    Active X Control SRINSTCOMMS