Analog universal active device: theory, design and applications

Abstract

This paper introduces the concept of what we call analog Universal Active Device (UAD), as an step forward from Dperational Amplifiers and other recently proposed active devices.The model of such device is proposed together with an approach to jbtain several practical silicon implementations for it. Non ideal :ffects of these practical implementations are theoretically analysed, md their influence in some circuit applications is comparatively jtudied. Simulation results are given supporting the Ideas presented here.

An ingenious methodology of deriving single‐FTFN‐based canonic grounded‐capacitor SRCOs

“…In fact, FTFNs or OFAs have been regarded as universal active elements. 19,[49][50][51] As a consequence, over the years, numerous applications of the FTFNs have so far been investigated, see previous works, [17][18][19][20][21][22][23][24][25][26][27][28][29][30][31]50,51 while several ways of realizing them in discrete circuit form as well as fully integratable forms have also been advanced by several researchers from time to time. For discrete applications, the FTFNs can be implemented, in practice, by using a composite connection of two Current Conveyors (CC) 41 characterized by i y = 0, v x = v y , i z = ±i x or two commercially available AD844-type Current feedback operational amplifiers (CFOA) 22,25,33,35 characterized by i y = 0, v x = v y , i z = i x and v w = v z .…”

“…On the other hand, the fully integratable bipolar/CMOS implementations of the FTFN have also been evolved; for instance, see previous studies 17,43,44,[50][51][52] and the references cited therein, for possible use in IC implementation of the functional circuits containing FTFNs.…”

“…The four‐terminal‐floating‐nullors (FTFN) † 41,42 or operational floating amplifiers (OFA) 43,44 are the generalized and more flexible embodiment of the concept of the nullor and are characterized by the terminal equations i x = 0, i y = 0; v x − v y = 0; i z = − i w = arbitrary, v z = arbitrary, v w = arbitrary. In fact, FTFNs or OFAs have been regarded as universal active elements 19,49–51 . As a consequence, over the years, numerous applications of the FTFNs have so far been investigated, see previous works, 17–31,50,51 while several ways of realizing them in discrete circuit form as well as fully integratable forms have also been advanced by several researchers from time to time.…”