A comparative study of CMOS based current feedback topologies (CFAs) suitable for low voltage applications

Abstract

A comparative study of CMOS-CFA is presented in this paper. By employing a second-generation positive current conveyor cascaded with amplifier followed by a buffer the design circumvents the problem of large transimpedance and high output impedance in a low voltage environment. It is observed that the reported configuration also results the near gain independent closed loop BW controlled by single feedback resistor. The reported circuit is simulated using 180nm and 90nm CMOS process technology and performance comparison of CFA characteristics is measured. As an application of the topology, the characteristics of low pass and band pass filters are also verified.