The impedance can be calculated at each point, and a frequency vs. To determine the actual real impedance value Z(W), a frequency sweep is generally performed. The AD5934 is available in a 16-ld SSOP.ĥ0KHz Max Excitation Output Impedance 20M Ohm, 12-Bit Resolution System Clock provided via MCLK pin DSP Real and Imaginary Calculation (FFT) 3V Power Supply, Programmable Sinewave Output Frequency Resolution 27 Bits (<0.1 Hz) Frequency Sweep Capability 12-Bit Sampling ADC Sampling 250KSPS, INL ± 1LSB Max Serial I2C Loading Temperature Range 125☌ 16 SSOP Clocking for both the DDS and ADC signals is provided externally via the MCLK reference clock, which is provided externally from a crystal oscillator. The ADC is a low noise, high speed 250 kSPS sampling ADC that operates from a 3 V supply. The gain stage for the response stage is 1 or 5.

To determine the impedance of the load at any one frequency point, Z(w), a measurement system comprised of a trans impedance amplifier, gain stage and ADC are used to record data. The real and imaginary data is available to the user through the 12C interface. At each point on the sweep the ADC will take 1024 samples and calculate a Discrete Fourier Transform to provide the real and imaginary data for the waveform. A Start Command is then required to begin the sweep. To perform the frequency sweep, the user must first program the conditions required for the sweep start frequency, delta frequency, step frequency, etc. Frequency resolution of 27 bits (less than 0.1 HZ) can be achieved. The signal is provided on chip using DDS techniques. Output ranges of 1 V, 500 mV, 200 mV can also be programmed. The system allows the user to program a 2 V PK-PK sinusoidal signal as excitation to an external load. The impedance can be calculated at each point and a frequency vs magnitude plot can be created. To determine the actual real impedance value Z(W), generally a frequency sweep is performed. The impedance magnitude and phase is easily calculated using the following equations:: The FFT algorithm returns a Real (R) and Imaginary (I) data word, allowing impedance to be conveniently calculated.

The response signal from the impedance is sampled by the on board ADC and FFT processed by an onboard DSP engine. The frequency generator allows an external complex impedance to be excited with a known frequency. The AD5934 is a high precision impedance converter system solution which combines an on board frequency generator with a 12-bit, 250 kSPS ADC.

Details, datasheet, quote on part number: AD5934 PartĢ50 kSPS 12-Bit Impedance Converter Network Analyzer

Impedance analyzer with external clock