Wide bandwidth cell impedance spectroscopy based on digital auto balancing bridge method

This paper presented the design of a cell impedance spectroscopy which based on a digital auto balancing bridge method. The hardware architecture of the system mainly consists of a reference source, a variable source, a null detector and a FPGA. DSP algorithms such as CORDIC-based direct digital synthesis and LMS-based auto balancing algorithm were discussed in detail. The simulation results show that the system has good performance from low frequency up to 10 MHz. Profiting from the cost efficiency and high flexibility of digital device, it suitable for EIS application in cell-level research.