New concept of virtual short circuit and virtual open circuit and derivation of two types of integrated operational amplifier

Abstract:

Since we own integrated operational amplifier, virtual short circuit and virtual open circuit and two types of integrated operational amplifier have emerged, but it has no necessary connection with the typical single-stage current series negative feedback and voltage parallel negative feedback, the two-stage voltage series negative feedback and current parallel negative feedback, and it have no detailed report. In this paper, we try to to accurate calculate i_b、u_be、A_uf according to two-way equivalent conversion of the feedback elements in the four circuits. When u_be and i_b approaching to zero at the same time is defined as virtual short and virtual break. When calculating A_uf , we should pay close attention to the two core components and ignore the secondary part of the project, and get the same result as the two types of integrated operational amplifier. In this way, not only the tedious and less used calculation of the original separation circuit is avoided, but also perfect transition from separation to integration is achieved.