Research of peak detector limiting characteristics for analog interface in impedance spectroscopy systems

A comparative analysis of the methods for obtaining the biological sensor impedance in electrochemical impedance spectroscopy (EIS) systems is made. It is shown that the use of the amplitude-phase method can improve the metrological characteristics of EIS systems due to a significant reduction in power consumption and simplification of the analog interface of the biological sensor. The realization of the peak detector on TSMC 0.35um SiGe technical process is considered. Due to the correction based on the proposed model of the peak detector, a relative error of 0.4% in the 10 GHz band and 3% in the 20 GHz band is achieved.