ABSTRACT
The available amplifier circuits can be divided into two main groups: single-and multi-stage architectures. The existing trade-off between speed and gain makes it difficult for complementary metal oxide semiconductor amplifiers to exhibit a high bandwidth and dc gain simultaneously. The realization of an amplifier, which features both high dc gain and bandwidth, can lead to conflicting demands. Various performance specifications can be taken into consideration for the choice of an amplifier structure. Operational trans conductance amplifiers, which are equivalent to a voltage controlled current source, are generally based on single-stage structures, while additional gain stages and an output buffer are required for the design of operational amplifiers operating as a voltage-controlled voltage source. An amplifier with a cascode configuration has the advantage of exhibiting a higher bandwidth due its improved isolation between the input and output nodes. Amplifiers should exhibit a high open-loop gain and a high bandwidth to minimize errors in the output voltage.
