15.1 Introduction

One of the most basic building blocks in the area of current-mode analogue signal processing is the current conveyor. As has been described in Chapters 3 and 4, an extensive literature on the application of current conveyors has evolved since the concept was originally disclosed in 1968 [1]. Over 100 references have demonstrated the universality of this element in the synthesis of almost all known active networks. Concurrently with these papers, a number of authors have outlined improved implementations designed to enhance the performance and utility of this circuit block. Although major progress has been made with these realizations, they were not entirely satisfactory, and it has been suggested as recently as 1988 [27] that the widespread acceptance of current-mode techniques by the working design engineer has been limited by the lack of standard integrated circuits available in the field ( Chapter 4). This dearth of devices is in marked contrast to the situation in the voltage domain, where a wide range of high performance ICs, such as operational amplifiers, are commonplace. In this Chapter, a new current conveyor IC based on a novel bipolar topology will be described which attempts to address this disparity.