A new design topology for low-voltage CMOS current feedback amplifiers

摘要

A new topology for designing low-voltage current feedback amplifiers (CFAs) is presented. By employing a second-generation positive current conveyor followed by an operational amplifier in an unconventional manner, the design circumvents the problem of trying to achieve large transimpedance in a low-voltage environment. It is shown that this CFA configuration also results in near gain independent closed-loop bandwidth defined by a single feedback resistor. The proposed amplifier was verified experimentally by a chip designed using Taiwan Semiconductor Manufacturing Company's 0.18-mum digital CMOS process of a single-ended power supply of 1.8 V