| 7280 | 7280BFP |
|  |  |
| General | Dual-phase DSP lock-in amplifiers operating over a reference frequency range of 0.5 Hz to 2.0 MHz. Direct digital demodulation using a main ADC sampling rate of 7.5 MHz. Wide range of extended measuring modes and auxiliary inputs and outputs. User-upgradeable firmware. |
| Measurement Modes | | |
| Outputs | The instrument can simultaneously show any four of these outputs on the front panel display:
X In-phase
Y Quadrature
R Magnitude
q Phase Angle
Noise | The following outputs are available:
X In-phase
Y Quadrature
R Magnitude
q Phase Angle
Noise |
| Harmonic Detection | nF n ?/font> 32 |
| Dual Harmonic | Simultaneously measures the signal at two different harmonics F1 and F2 of the reference frequency |
| Dual Reference | Simultaneously measures the signal at two different reference frequencies F1 and F2 where F1 is the external and F2 the internal reference |
| Frequency Ranges for Dual Harmonic and Dual Reference Modes: |
| Standard Unit | F1 and F2 ?/font> 20 kHz |
| With option -/99 | F1 and F2 ?/font> 800 kHz |
| With option -/98 | F1 and F2 ?/font> 2.0 MHz |
| Virtual Reference | Locks to and detects a signal without a reference (100 Hz ?/font> F ?/font> 2.0 MHz) |
| Noise | 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 2.0 MHz. 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 | Not available |
| Display | 320 ?/font> 240 pixel (?VGA) electroluminescent panel giving digital analog bar-graph and graphical indication of measured signals. Menu system with dynamic key function allocation. On-screen context sensitive help | Not fitted |
| Signal Channel | | |
| Voltage Input | | |
| Modes | A only -B only or Differential (A-B) |
| Full-scale Sensitivity | |
| 0.5 Hz ?/font> F ?/font> 250 kHz | 10 nV to 1 V in a 1-2-5 sequence |
| 250 kHz < F ?/font> 2.0 MHz | 100 nV to 1 V in a 1-2-5 sequence |
| Max. Dynamic Reserve | > 100 dB |
| Impedance | 100 MW // 25 pF |
| Maximum Safe Input | 20 V pk-pk |
| Voltage Noise | 5 nV/?/font>Hz @ 1 kHz |
| C.M.R.R. | > 100 dB @ 1 kHz |
| Frequency Response | 0.5 Hz to 2.0 MHz |
| Gain Accuracy | ?.3% typ ?.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 kW 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 in a 1-2-5 sequence |
| Wide Bandwidth | | |
| F ?/font> 250 kHz | 1 pA to 100 in a 1-2-5 sequence |
| F > 250 kHz | 10 pA to 100 in a 1-2-5 sequence |
| Max. Dynamic Reserve | > 100 dB |
| Frequency Response (-3 dB): |
| Low Noise | ?/font> 500 Hz |
| Normal | ?/font> 50 kHz |
| Wide Bandwidth | ?/font> 1 MHz |
| Impedance | |
| Low Noise | < 2.5 kW @ 100 Hz |
| Normal | < 250 W @ 1 kHz |
| Wide Bandwidth | < 25 W @ 10 kHz |
| Noise | |
| Low Noise | 13 fA/?/font>Hz @ 500 Hz |
| Normal | 130 fA/?/font>Hz @ 1 kHz |
| Wide Bandwidth | 1.3 pA/?/font>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 kW to ground |
| Reference Channel | |
| TTL Input | |
| Frequency Range | 0.5 Hz to 2.0 MHz |
| Analog Input | |
| Impedance | 1 MW // 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?/font> increments |
| Phase Noise at 100 ms TC 12 dB/octave slope: |
| Internal Reference | < 0.0001?/font> rms |
| External Reference | < 0.01?/font> rms @ 1 kHz |
| Orthogonality | 90?/font> ?.0001?/font> |
| 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 Zero Stability | | |
| Digital Outputs | No zero drift on all settings |
| Displays | No zero drift on all settings | Not Available |
| Analog Outputs | < 5 ppm/?/font>C |
| Harmonic Rejection | -90 dB |
| Output Filters | | |
| X Y and R outputs only | |
| Time Constant | 1 to 1 ms in a 1-2-5 sequence and 4 ms |
| Slope (roll-off) | 6 and 12 dB/octave |
| All outputs | | |
| Time Constant | 5 ms 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: ?00% full-scale |
| Absolute Phase Measurement Accuracy | ?/font> 0.01?/font> |
| 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 | ?.2% |
| Stability | 50 ppm/?/font>C |
| Output Impedance | 50 W |
| 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 | 20 Hz maximum (50 ms/step) |
| Auxiliary Inputs | | |
| ADC 1 2 3 and 4 | | |
| Maximum Input | ?0 V |
| Resolution | 1 mV |
| Accuracy | ?0 mV |
| Input Impedance | 1 MW // 30 pF |
| Sample Rate | |
| ADC 1 only | 40 kHz max. |
| ADC 1 and 2 | 17.8 kHz max. |
| Trigger Mode | Internal External or burst |
| Trigger Input | TTL compatible |
| Outputs | | |
| Main Analog (CH1 and CH2) Outputs: | |
| Function | X Y R q Noise Ratio Log Ratio and User Equations 1 & 2. |
| Amplitude | ?.5 V full-scale; linear to ?00% full-scale |
| Impedance | 1 kW |
| Update Rate | | |
| X Y or R @ TC ?/font>4 ms | 7.5 MHz |
| All outputs @ TC ?/font>5 ms | 1 kHz |
| Signal Monitor | | |
| Amplitude | ? V FS |
| Impedance | 1 kW |
| Auxiliary D/A Output 1 and 2: | |
| Maximum Output | ?0 V |
| Resolution | 1 mV |
| Accuracy | ?0 mV |
| Output Impedance | 1 kW |
| 8-bit Digital Port | 0 to 8 lines can be configured as inputs with the remainder being outputs. Each output line can be set high or low and each input line read to allow interaction with external equipment. Extra line acts as trigger input |
| Reference Output | | |
| Waveform | 0 to 3 V rectangular wave active in External Reference Mode only |
| Impedance | TTL-compatible | |
| Power - Low Voltage | ?5 V at 100 mA rear panel 5-pin 180?DIN connector for powering SIGNAL RECOVERY preamplifiers |
| Data Storage Buffer | | |
| Size | 32k ?16-bit data points may be organized as 1?2k 2?6k 3?0.6k 4?k etc. |
| Max Storage Rate | | |
| From LIA | up to 1000 16-bit values per second | |
| From ADC1 | up to 40000 16-bit values per second | |
| User Settings | | |
| | Up to 8 complete instrument settings can be saved or recalled at will from non-volatile memory | Not available |
| Interfaces | | |
| | RS232 and GPIB (IEEE-488). A second RS232 port is provided to allow "daisy-chain" connection and control of up to 16 units from a single RS232 computer port |
| General | | |
| Power Requirements | | |
| Voltage | 110/120/220/240 VAC | |
| Frequency | 50/60 Hz | |
| Power | 200 VA max | |
| Dimensions | | |
| Width | 17?quot; (435 mm) | |
| Depth | 19" (485 mm) | |
| Height | | |
| With feet | 6" (150 mm) | |
| Without feet | 5?quot; (130mm) | |
| Weight | 25.4 lb (11.5 kg) |
