Current-Mode Instrumentation Amplifiers Using Current Conveyors

Abstract

In this chapter, various CMIA topologies built upon current conveyors are discussed. Based on operation, we categorize them in two groups of basic and enhanced topologies. The basic category includes the CMIA proposed by Wilson and its advanced version proposed by Gift. In this category, only one common-mode cancellation mechanism is used and common-mode inputs are attenuated by performing a subtraction action at input stage. The enhanced category employs double common-mode cancellation mechanism and common-mode signals are attenuated in two steps. In this category, common-mode inputs are first attenuated by a subtraction action at input stage and then another mechanism is used to cancel the remaining common-mode components from the first stage. The second category (which includes the CMIAs proposed by Khan et al., Su and Lidgey, Galanis et al., Gkotsis et al., Koli et al., Azhari and Fazlalipour) is usually built by modifying the Wilson CMIA by adding an extra common-mode cancellation circuit. The advantages and limitations of each topology are highlighted. © 2019, Springer Nature Switzerland AG.