Versatile Active Elements, Structure, and Applications

Abstract

As an active building block, operational amplifier played a predominant role in the last two decades and an enormous number of publications exist in the literature on various circuit examples so that the design engineer can make choice of them. However, op-amp-based circuits exhibit several drawbacks in their performance arising from the limited bandwidth and slew rate of these active elements.In the last two decades, several works on active devices were performed and a lot of works appeared in the available literature. In a recent work, a new active building block, CDBA (current differencing buffered amplifier), is introduced by Acar and Özoguz to provide further possibilities in the circuit synthesis and to simplify the implementation. Furthermore, one important work is performed by Biolek et al. where the main problem is described and several new active devices are introduced.In this section we describe CMOS realization of some versatile active devices such as CDBA, CDTA, and VDTA, giving CMOS realization topologies with application examples demonstrated by simulations and some experimental results. For CMOS realizations, the layouts of the related overall design are also given in the chapter.KeywordsAnalog circuitsVersatile active devicesCDBACDTAVDTAFilters