Design And Simulation Of Current-mode Filter Employing CCCCTA

Continuous-time filter is widely applied in fields such as communication,electronic measurement,instrumentation,and automatic control and the design of it is an important topic in circuits and systems field.Current-mode filter is an important type in analog filter due to its high speed,low power consumption,wide dynamic range,and so on.Current controlled current conveyor transconductance amplifier(CCCCTA)is a new type of active devices integrating current controlled current conveyor and transconductance amplifier together,which has drawn considerable attention since it was launched.Many filters,oscillators and other functional circuits are designed with CCCCTA as the active device.Since a parasitic resistor controlled by bias current exists in x tenninal of the device,resistor element is not neccessary in CCCCTA-based filters.Relevant filter design is conducted in this thesis based on CCCCTA.The main research contents of thesis are as follows:(1)Based on the existing CCCCTA circuit,a multi-z-terminal or multi-output current controlled current conveyor transconductance amplifier is designed using current mirrors or cross-coupled current mirrors,and then PSPICE simulation is performed,with the parameters of the device being obtained.Meanwhile,a current amplifier and a current-mode lossy integrator circuit based on CCCCTA are proposed,which are used to design multi-phase oscillators and high-order filters.(2)We put forward a KHN current-mode filter which consist of multi-output CFTA and multi-output CCCCTA(as active devices)and two grounded capacitors.Meanwhile,a current-mode three-input single-output second-order filter is given,which comprised two CCCCTAs and two grounded capacitors and can provide five filtration functions simultaneously,including low pass,high pass,band-pass,band-stop,and all-pass.The circuit is simple,particularly suitable for integrated implementation,and its input impedance is low but output impedance is high,making it very convenient to realize cascade connection and produce a high-order filter.(3)A current-mode FAF based on CCCCTA is proposed,which include three types of circuits,named Class 0,Class 1,and Class 2 FAF.The filter structure is composed of CCCCTA and two passive grounded capacitors.These circuits are easy to integrate and implement,causing low power losses.With high output impedance,the load can be driven by the current easily.Center frequency and quality factor are adjusted by different bias currents separately,and tuning ratio is large as well.(4)Two current-mode multiphase sinusoidal oscillators are designed,which are formed through cascade connections of current-mode lossy integrators and first-order all-pass filters respectively.Meanwhile,the corresponding calculation formulas of oscillation starting condition and oscillation frequency are deduced.The two oscillators have advantages of simple circuits,easy operation,and the ability to change oscillation frequency without affecting oscillation conditions.(5)Two current-mode high-order all-pass filters with CCCCTA as the active device are designed by adopting signal flow graphs and the jump-coupling design method which simulate LC ladder network,with the corresponding design formula being deduced.The circuit obtained is equipped with n+1 or n CCCCTAs and n grounded capacitors,featuring low sensitivity and full integration.PSPICE simulation verified the feasibility of the design and the validity of the theoretical analysis.The proposed filter have certain advantages over the filters were designed in the references.