A Low Noise Power Design for Electrical Impedance Tomography System

This paper describes a quality power module design for Biological Electrical Impedance Tomography (BEIT) system based on FPGA. As the electrical signals on the boundary of subject are too weak to measure effectively, it is essential to design a data acquisition system with high SNR and extremely low noise. This paper is focus on the power module design because the quality of the power module impacts the performance of the data acquisition system directly. The BEIT system needs several kinds of power supply to work effectively, such as 12V, 5V. In this paper, the power module is supplied by DC18V, using Buck-type DC/DC and LDO technologies, a set of independent power supply scheme is carried out, and provides stability and low noise power sources. The expected powers with ripple less than 20mV are achieved, which can preferably meet the BEIT system power supply requirements.