The Research On The Current Controlled Conveyor & Application

Current conveyor,as a circuit component which has lots of characters and works as operational Amplifier, has been widely used in analog integrated circuit. The second generation current controlled conveyor, which is derived from current conveyor, has not only the characters of current conveyor, but also the characters of OTA.The paper analyzes the fundamental part circuit of current conveyor,the current mirror and the voltage follower. After introduction of the tranlinear loop principal, the BJT current controlled conveyor has been designed by using mixed tranlinear loop voltage follower. As for modern integrated circuit, the model of MOS transistor, the active resistance and the current mirror integrated circuit formed by MOS transistor are introduced. The CMOS current controlled conveyor has been derived from mixed tranlinear loop CMOS voltage follower based on weak inversion operation. After a brief introduction about BiCMOS technology, the advantages of BiCMOS current mirror have been analyzed. And the BiCMOS current controlled conveyor has been discussed.Using current controlled conveyors, the designs of active components, function circuits, filters and oscillators have been systematically presented in this paper. The circuits are not only easy to integrated, but also adaptable. In the last section, as the design methods of high-order current-mode integrated filters, the equivalent circuits and the multi-loop feedbacks are systematically expounded. And a novel systematically method, using Linear Combination Approach to design high order filter, has been proposed. The designed filters can be adapted by adjusting the bias currents, without changing the physical structure. The results of the examples and Pspice simulator show the advantages and availabilities of this method.