Design of Voltage-Mode, Trans-Admittance-Mode, Trans-Impedance-Mode and Current-Mode Biquad Filters Employing Plus TypeCurrent Feedback Amplifiers

摘要

In this paper two filter configurations one operating in voltage-mode(VM) and the other in trans-impedance-mode(TIM) with each employ-ing three non-inverting current feedback amplifiers (CFAs) along withseven passive components are presented. The VM filter with threeinputs and three outputs enjoy the features of: realizing all the genericfiltering functions by proper choice of inputs with three responsessimultaneously, ideal for cascading due to its inputs at high impedancesand outputs at low impedances, and realizing trans-admittance-mode(TAM) filtering functions from the same topology. The TIM cir-cuit with a single input and three outputs has the features of: realizingthree filtering functions simultaneously, ideal for cascadibility becauseof having input at zero impedance and outputs at low impedances, andimplementing current-mode(CM) filtering responses from the sameconfiguration. These filtering topologies besides having low active andpassive sensitivities show that their filtering parameters cut-off fre-quency (w0), bandwidth(colQ), quality factor(Q) and gain(H0) permiteither orthogonal or independent adjustment .The current and voltagetracking errors of the active devices have been included and to confirmthe theoretical analysis, experimental and PSPICE simulation resultsare shown.