DXA-001C Independent Synchronous Dual-Channel Lock-in Amplifier

DXA-001C Independent Synchronous Dual-Channel Lock-in Amplifier

Input signal channel

The low-noise analog front-end amplifier used in the lock-in amplifier DXA-001C can effectively handle differential or single-ended signals, and its equivalent input noise is only 5nV/√Hz. The input impedance of this channel is 10MΩ, and the input signal level that can be detected at full scale output is 1nV to 1V. In addition, the DXA-001C can be applied to the measurement of input current signals with a front-end variable current gain of 106 or 108 V/A. DXA-001C has two independent signal input channels to meet the needs of users to detect multiple signals at the same time.

 

Reference signal channel

The DXA-001C digital lock-in amplifier has 2 reference signal channels, both of which can choose to use the internal reference mode or the external reference mode. When the DXA-001C is set to the internal reference signal mode, the high-precision oscillator and digital synthesis algorithm inside the instrument can generate a sine wave signal for multiplying the input signal. At this time, the internal reference signal is hardly affected by phase noise. Impact. Using digital phase shifting technology, the phase of the internal reference signal can achieve a resolution accuracy of 0.001°. The instrument's internal reference signal mode works well in the frequency range from 1 mHz to 102 kHz. In external reference signal mode, both sine wave signal and TTL logic level can be used as external reference signal. The rising or falling edge of the external reference signal will trigger the internal phase-locked loop (PLL) to lock.

Display function

What DXA-001C chooses for use is a 5.6-inch TFT color screen with a resolution of 640×480 as the main display screen of the instrument. The data detected by this lock-in amplifier, such as X value, Y value, R value, and θ value of the signal, can be displayed in numerical value, bar graph, XY coordinate graph, polar coordinate display, etc. at the same time. Data from two channels can be displayed simultaneously.

 

Simultaneous measurement of multiple harmonics

In the traditional lock-in amplifier, only the fundamental frequency signal or a certain harmonic signal component can be measured at the same time. Therefore, for some situations that require the amplitude and phase of multiple frequency components at the same time, the traditional lock-in amplifier cannot meet the measurement requirements. The digital end of DXA-001C combines FPGA and ARM technology to achieve higher processing bandwidth and more flexible digital architecture. The digital processing accuracy can reach 48 bits, and it can measure harmonics of 3 frequencies at the same time, making one DXA-001C is equivalent to 6 traditional lock-in amplifiers. The detected maximum harmonic signal frequency can reach 32767 times the fundamental frequency, but the maximum harmonic frequency cannot exceed the instrument's operating frequency of 102 kHz.

PC software operation

The standard USB2.0 interface, RS232-DB9 interface, and GPIB (optional accessory) adopted by this instrument ensure that users can effectively use all the test functions of OE1022D on the control computer, including setting reasonable control parameters of the instrument and reading the instrument measured data. This instrument is equipped with a corresponding free LabVIEW program, which enables the DXA-001C to be easily applied to complex scientific experiments. On the LabVIEW interface, the user can see all control commands and instrument feedback responses.

 

Dual channel signal channel

Voltage input mode: single-ended or differential input
Full-Scale Sensitivity: 1 nV to 1 V in 1-2-5 steps
Current input gain: 106 or 108 V/A
Common Mode Rejection Ratio: >100 dB to 10 kHz, reduced by 6 dB/oct
Dynamic Reserve: >120 dB
Gain accuracy: standard 0.2%, maximum 1%
Voltage noise: 5 nV/√ Hz
Current noise: 15 fA/√ Hz
Power frequency filter: 50 Hz and 100 Hz
Input shield grounding: BNC (A/I, B) shield can be directly grounded or connected to floating ground through a 10kΩ resistor

Demodulator

Digital output: All settings have no zero drift

Display: All settings have no zero drift

Analog output: All dynamic reserve settings are less than 5 ppm/°C

Harmonic suppression: -90 dB

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

Sync filter: Effective below 200 Hz with 18,24 dB/oct dip

 

Auxiliary Inputs and Outputs

CH 1 and CH 2

Function: Output X, Y, R, θ, Harmonics and DC

Amplitude: ±10 V

Drive current: ±30mA max

AUX Inputs

 Function     4-channel input

Amplitude ±10 V, 1 mV resolution

Impedance 1 MΩ

Trigger Input

TTL external trigger for data storage

Monitor Output

Analog output of signal amplifier

Drive current ±40mA max