AD5933 - Part 1

AD5933 1 MSPS, 12-Bit Impedance Converter

AD5933 1 MSPS, 12-Bit Impedance Converter, Network Analyzer Data Sheet 

GENERAL DESCRIPTION 

The AD5933 is a high precision impedance converter system solution that combines an on-board frequency generator with a 12-bit, 1 MSPS, analog-to-digital converter (ADC). 

The frequency generator allows an external complex impedance to be excited with a known frequency. 

The response signal from the impedance is sampled by the on-board ADC and a discrete Fourier transform (DFT) is processed by an on-board DSP engine. 

The DFT algorithm returns a real (R) and imaginary (I) data-word at each output frequency. 

Once calibrated, the magnitude of the impedance and relative phase of the impedance at each frequency point along the sweep is easily calculated. 

This is done off chip using the real and imaginary register contents, which can be read from the serial I2C interface. 

A similar device, also available from Analog Devices, Inc., is the AD5934, a 2.7 V to 5.5 V, 250 kSPS, 12-bit impedance converter, with an internal temperature sensor and is packaged in a 16- lead SSOP.

AD5933 takes much longer to preform a frequency sweep than expected

#Jonah, ah, let me see. 

The datasheet specifies typical sample rate of 1 Msps, or sample time 1 us. 

Your result of 90 ms comparing to the 2105 paper's 3 ms of course is unreasonably slow. 

I would suggest the following troubleshooting methods: 

(1) set frequency sweep from 100 to 50 points, and see if sample time decreases from your 90 ms to something better. 

(2) Your debugging "Serial.print()" statements of course slow things down quite a bit. 

Perhaps you can uncomment all the print statements and timestamp before and after testing to calculate average sample time lapse. – tlfong01 36 mins ago    

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