An In-Depth Exploration of Different Analog Circuit Parameters Utilizing Three Amplifier Topologies: A Robust Examination of Gain, Power, Noise, and Bandwidth Characteristics

A comparative investigation of transient and AC behaviors of the differential amplifier, cascode operational amplifier, and folded cascode op-amp was performed on Cadence Virtuoso in a 90 nm technology node. The circuits were driven at 1 V with a circuit current of 1 μA. Power consumption, gain, bandwidth, and noise were critically analyzed to compare the performance of these three amplifiers viz. (a) Case-1: differential amplifier, which produced a gain of 10.26 dB, power of 290.4 nW, the noise of 164.1 nV/√Hz, and bandwidth of 23.89 MHz, onwards (b) Case-2: cascode op-amp, that developed gain of 20.59 dB, power of 403.1 nW, noise of 179.6 nV/√Hz, and bandwidth of 1.015 MHz, and ultimately, (c) Case-3: folded cascode op-amp, which generated the aforementioned parameters as 25.02 dB, 684.4 nW, 192.5 nV/√Hz, and 3.822 MHz, respectively. It was found that the folded cascode operational amplifier had a maximum gain. In contrast, the differential amplifier could be operated on a wide range, and the designed differential amplifier was more stable.