Complex impedance measuring instrument based on AD5933

At present, the general method of measuring complex impedance is to apply an excitation signal of a certain frequency to the unknown impedance, and then sample and analyze the response signal. Discrete Fourier transform (DFT) is usually used. The DFT result returns the response signal at the corresponding frequency. The mode value and phase are then calculated to obtain the mode value and phase information of the measured complex impedance.

Complex impedance testing equipment generally needs to solve the following problems:
1. Measurement safety. Since the system environment where the testing equipment is located is diverse and uncertain, it is necessary to consider adding an isolation device between the testing equipment and the host.
2. From the perspective of flexibility, since the current applications of impedance analysis are different, the mode value and frequency of the excitation signal used, and the measurement range of the impedance have specific test range requirements.
3. Considering that the impedance network under test may be complex, it cannot simply be analyzed by a resistive model. Instead, the mode value and phase of the measured signal need to be accurately analyzed at the same time, so the system accuracy is required to be high.
4. If portable applications are required, low power consumption and small size design are also particularly important design factors.
The complex impedance measuring instrument based on AD5933 launched by ADI can solve the above problems.

AD5933 is a high-precision impedance converter system solution:
• Internal DDS generates the excitation voltage signal
• Users can adjust the rate and amplitude of the excitation frequency signal
• Internal 12-bit ADC samples the response signal
• Internal integrated DSP at the corresponding frequency point Perform DFT

   In addition, the complex impedance measuring instrument provided by ADI provides an impedance analysis software specifically used for measurement demonstration in conjunction with hardware system measurement and demonstration. It has a humanized graphical user interface so that users can accurately and quickly analyze and observe the measured object. Measure changes in impedance.

Click to download the complete document and resources.

The complete document includes the following content:
 1. Full version user manual
 2. Impedance analysis system software
 3. MCU firmware file
 4. Hardware schematic diagram, PCB board diagram and geber file
 5. Other related tools: ARMWSD- ADuC7xxx Series of serial port downloaders