Generalized gyrator implementation techniques using unity-gain cells

Abstract

All possible gyrator circuits using the minimum number of voltage and current unity-gain cells are extracted, as a result of generalizing the unity gains, such that a unity gain can be + 1 or −1. Since second-generation current conveyors (CCIIs), possessing both voltage and current unity-gain cells, are very suitable for such gyrators, it is shown that inclusion of the recently proposed ‘inverting secondgeneration current conveyor’ (ICCII) in the design enables implementation of all types of extracted gyrators. The number of possible gyrator configurations is eight, one of them being the well-known Sedra–Smith gyrator and another its x -input counterpart; both utilize only CCIIs. The remaining possible six gyrators are new and utilize ICCIIs as well. Like the Sedra–Smith gyrator, all the circuits employ a minimum number of passive elements and similar types of active components, namely CCIIs and/or ICCIIs. The effects of current conveyor non-idealities and parasitics on important gyrator applications are also investigated. A highperformance dual-output CMOS ICCII is designed and used in SPICE simulations of two important gyrator applications in order to verify the theoretical results. Also, as a design example, an elliptic filter is realized and simulated.