Calculator-aided evaluation of integrated n-m.o.s. operational amplifiers

In this paper, the results are given of an investigation of first-generation integrated n-m.o.s. operational amplifiers. Calculator-aided simulation is used to study the performance and limitations of the stages and the overall amplifier. Quiescent conditions, differential-mode gain and common-mode gain are investigated. The transfer function of the overall amplifier is determined. The slew rate has been investigated, taking into consideration the complicated open-loop gain and the nonlinearity of the amplifier´s different stages. Finally, an improvement in the circuit design of integrated n-m.o.s. operational amplifiers is suggested. This is especially suited to amplifiers fabricated by advanced technologies.