The Application Of Four Terminal Floating Nullor In The Design Of Filters

This paper sets forth the development of integrated circuit, comparing our country's information to the world's. It shows the necessity and importance of the research of current-mode circuit in analog integrated circuit. It introduces the circuit principles, which are used in four-terminal floating nullor, including current mirror and translinear principle. It also introduces four physical implementations. Based on analysing deeply FTFN's application in the design of the second-order filters, this paper proposes a realization of second-order current-mode three inputs and single output filter using FTFNs. The circuit of this filter can realize the five current transfer functions of low-pass,high-pass,band-pass,notch and all-pass. Based on analysing FTFN's application in the design of oscillators, this paper proposes a realization of low-pass multi-phase sinusoidal oscillator and a realization of all-pass multi-phase sinusoidal oscillator. It discusses the realization of parallel and series R-L and C-D immittance using FTFNs and parallel and series (-R)-(-L) and (-C)-(-D) immittance using FTFNs. It discusses the application of FTFN in highorder filter, and proposes a realization of third-order elliptical filter using FTFNs through the method of signal-flow. This paper does a research in nth-order filters, proposes three configurations based on FTFN with three methods. In modem systems,analog and digital, circuits are implemented in the same integrated circuit chip. So this paper introduces the fullybalanced FTFN(FBFTFN), including the common-mode feedback principle, which is used in FBFTFN, and two implement circuits. It discusses FBFTFN's application in the design of filters, and proposes a realization of fifth-order low-pass filter using FBFTFNs. The circuits, which are proposed in this paper, are simulated by PSPICE. The simulation results verify their configurations are applicable.