The use of adjoint transformation method to transformation current mode from voltage mode in universal active element based filters

Bu çalışmada, ek dönüşüm (Adjoint Transformation) yöntemiyle işlemsel yükselteç (Operational Amplifier-OA) tabanlı gerilim modlu süzgeç devresinden, akım modlu FTFN'li ve CCII- tabanlı süzgeç devresine dönüşüm işlemi tanıtılmıştır. Ancak akım modlu CCII- tabanlı süzgeç devresine dönüşüm işlemi için önce "Dönüşüm Teoremi" gereğince gerilim modlu CCII- tabanlı süzgeç devresine dönüşüm yapılmıştır. Akım modlu yapıya dönüşüm işlemi sırasında nullor modeli kullanılmıştır. Bu model, FTFN ile nullator-norator çiftinin herhangi bir ön koşul olmaksızın yerdeğiştirebileceğini açıklamaktadır. Böylece, gerilim modlu işlemsel yükselteçten akım modlu FTFN'ye dönüşümün kolay olduğu gösterilmektedir. Bu çalışma da ek dönüşüm yöntemi değişik uygulamalarla Türkçe literatüre tanıtılmaya ve kazandırılmaya çalışılmıştır. Uygulamada kullanılan süzgeç devrelerinin karakteristikleri, PSPICE benzetim sonuçlarıyla doğrulanmıştır.

Üniversal aktif eleman tabanlı süzgeçlerde gerilim modundan akım moduna geçişte ek dönüşüm yönteminin kullanılması

In this study, a transform procedure for the realisation of current-mode FTFN and for CCII-based filters from voltage-mode operational amplifier-based filter was presented by an adjoint transfomation method. First of all, a transformation to voltage-mode CCII-based filter circuit was performed according to the "Transformation Theorem" for the transformation to current-mode CCII-based filter circuit. Nullor model was used during the procedure of transformation to current-mode structure. This model shows that, nullator-norator pair can be used instead of FTFN without any restriction. Therefore, it is shown that transformation from voltage-mode operational amplifier to current-mode FTFN is easy. In this study, adjoint transformation method was introduced and acquired to Turkish literature by different applications. Characteristics of filters that used in applications were confirmed by PSPICE simulation results.

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