Impeadance Testing using AD5940 EVAL ELCZ


I have recently purchased AD5940 EVAL ELCZ and wanted to test the board by measuring impedance / reactance offered by a 100uF electrolytic capacitor 

I used SensorPal GUI to collect the magnitude and phase of impedance values ranging from 10KHz to 1Hz

The external connection was Micro usb to crocodile clip and connected green one to one end of the capacitor and red and blue to the other end

The output values were far from accurate

While performing the test, I placed JP 9 , 10 and 11 in position C and JP 6 in B 

Kindly guide me through the correct process to measure impedance using crocodile clips and SensorPal.

Measurement Parameters Settings:

Start Frequency 10000 Hz
Points 100
Amplitude 100 mVpp
Enable 1
Stop Frequency 1 Hz
Logarithmic 1
Power Mode Low Power
Sample Rate 20 sps
Internal RTIA Selection 1K Ω
Calibration Resistor 10000 Ω
Filter Level Level 1.1
Hanning Window 1
DFT Number 16384
PGA Gain Select GNPGA_1
Counter Electrode CE0
Sense Electrode SE0LOAD
  • 0
    •  Analog Employees 
    on Aug 30, 2021 7:55 AM


    The connections and jumper settings are correct.

    For measurement at low frequencies, use the following ADC filter settings :

    .ADCSinc2Osr = 11; //ADCSINC2OSR_1333
    .ADCSinc3Osr = 1; //ADCSINC3OSR_4
    .DftNum = DFTNUM_16384;
    .NumClks = 0;
    .HighPwrMode = bFALSE;

    Note: It takes long time to measure at low frequencies.