Improving the Accuracy of the Single Chip Impedance Analyzer for Sensor Applications

The ways to use the single chip impedance analyzers AD5933 and AD5934 in various impedimetric sensor applications is presented. Spectral leakage impact on the accuracy of quadrature conversion based on algorithm of single-point Fourier transform across is scrutinized. The efficiency of the Hann and BlackmanHarris window functions for decreasing the leakage error is investigated. It is shown that application of the Hann window reduces leakage error in several times, but even though it remains on the unacceptable level (over 25 %). Significantly better results are achieved for the Blackman-Harris window (error can be reduced to 0.1 %). Copyright © 2013 IFSA.