A New Current-Mode Current-Controlled Universal Filter Based on CCCII(±)

This paper proposes a new current-mode current-controlled single-input multiple-output type universal filter using non-inverting and inverting second generation current-controlled conveyors (CCCII(±)s). The proposed circuit employs four CCCII(±)s and two grounded capacitors, and it can simultaneously realize lowpass, bandpass, highpass, bandstop and allpass filter outputs. The circuit offers an independent electronic control of the natural angular frequency (ω ₀) and quality factor (Q) by means of adjusting the bias current of the CCCII(±)s. The parameter sensitivities are all very low. Moreover, a high Q-value filter can be easily obtained by adjusting the ratio of two bias currents. PSPICE simulation results at the natural frequency of 1.27 MHz are given to demonstrate the advantages of the proposed circuit. This work was supported by National Natural Science Foundation of China under No.60676021.     

All-pass filters based on CCII− and CCCII−

This paper proposes a first-order all-pass filter using one negative type second-generation current conveyor (CCII?), two resistors and a capacitor. From the proposed CCII? based filter, by replacing the CCII? and a resistor by a negative second-generation current-controlled conveyor (CCCII?) a new filter is developed which requires only one each of CCCII?, capacitor and resistor. The experimental and simulated results are found in good agreement with theoretical analysis. The circuits are also analyzed for non-ideal current conveyors to show that they still function as all-pass filters but with slight altered values of gain and phase.     

A new electronically tunable phase shifter employing current-controlled current conveyors

A new canonical current-mode (CM) filter topology is presented. It realizes first-order allpass filtering functions using two dual-output current-controlled current conveyors (DO-CCCII) and a single capacitor. The topology gives both inverting and non-inverting types of these filters. Owing to electronically tunability properties of the CCCII, phase response of the circuit can be controlled by an external control current. Realization of the allpass filter imposes no matching condition. All outputs of the filters exhibit high output impedances so that this property makes the circuits very attractive from the viewpoint of cascading in current mode. The theoretical results are verified with PSPICE simulations using a BJT realization of CCCII.     

Systematic synthesis of CCCCTA-based T-T filters using NAM expansion method

In the light of nullor-mirror models for current-controlled current conveyor trans-conductance amplifier (CCCCTA), initiating the admittance matrices of the Tow-Thomas (T-T) filter, three different types of the T-T filter are synthesised by means of the nodal admittance matrix (NAM) expansion method. The type A filter, which employ one CCCCTA, one grounded resistor and two grounded capacitors, has eight different forms, the type B filter, which employ one CCCCTA, two grounded capacitors and a second-generation current-controlled conveyor (CCCII) or an second-generation inverting current-controlled conveyor (ICCCII) or an operational trans-conductance amplifier (OTA), has 64 different forms and the type C filter employing one CCCCTA and two grounded capacitors has eight different forms. In all, 80 voltage-mode/current-mode T-T filter circuits are obtained. Because of using canonic number components, the circuits are highly desirable from the viewpoint of IC fabrication and their parameters can be electronically tuned through tuning bias currents of CCCCTAs. The hand analysis and computer simulation results have been provided to support the synthesis method.     

Low-voltage low-power multifunction current-controlled conveyor

In this study, low-voltage low-power multifunction current-controlled conveyor (CCCII) is introduced. Multifunction current conveyors are able to achieve various CCCII structures with a small modification in the circuit. The proposed circuit required ±0.5 V as a power supply, a simple circuit structure and low power consumption. The power consumption is only 4.8 µW. Low-voltage operation is achieved by using changeable threshold voltage and PMOS level-shifter current mirror. This circuit is able to operate as CCCII± with both positive and negative intrinsic resistance, which have a wide tunable range with a small modification in the circuit connections.     

Simple first-order translinear-C current-mode all-pass sections

A first-order translinear-C current-mode (CM) all-pass section (APS) using two current-controlled conveyors (CCCII) and a single capacitor is given. A canonical CM-APS using only one dual-output CCCII and one capacitor is also derived from the proposed configuration. The circuits are analysed for the non-idealities of CCCII and possess attractive sensitivity performance. The proposed circuits are electronically tunable over a wide frequency range. RSPICE simulation results for ac analysis, transient analysis and harmonic distortions are incorporated to verify the theory.     

Systematic Synthesis on Pathological Models of CCCII and Modified CCCII

According to the equivalent view for the terminal current-voltage constraint relationship between pathological elements and the various second-generation current-controlled convegors (CCCIIs), four pathological models for the CCCII are first derived by means of the nodal admittance matrix expansion in this paper. Moreover, 48 new pathological models for the modified CCCII are also synthesized. The derived pathological models for the various CCCIIs are expected to be useful in circuit analysis and synthesis.     

High output impedance current-mode universal filter employing dual-output current-controlled conveyors and grounded capacitors

A novel current-controlled two-input three-output current-mode universal filter, which employs only three dual-output controlled-controlled current conveyors (DOCCCIIs) and two grounded capacitors, is presented in this paper. The proposed configuration provides inverting-type lowpass, noninverting-type lowpass, inverting-type bandpass, noninverting-type bandpass, highpass, bandstop and allpass current responses at a high impedance terminal, which enable easy cascadability. The filter also offers an independent electronic control of the natural frequency ω_o and the parameter ω_o/Q through adjusting the bias current of the DOCCCII. No critical matching condition is required for realizing all the filter responses, and all the incremental parameter sensitivities are low. The performances of the proposed circuit are simulated with PSPICE to confirm the presented theory.     

Current‐Mode Electronically Tunable Universal Filter Using Only Plus‐Type Current Controlled Conveyors and Grounded Capacitors

In this paper we present a new current‐mode electronically tunable universal filter using only plus‐type current controlled conveyors (CCCII+s) and grounded capacitors. The proposed circuit can simultaneously realize lowpass, bandpass, and highpass filter functions—all at high impedance outputs. The realization of a notch response does not require additional active elements. The circuit enjoys an independent current control of parameters ω₀ and ω₀ / Q. No element matching conditions are imposed. Both its active and passive sensitivities are low.     

Encrypted communications: towards very low consumption frequency-hopping active filters

The principal techniques of coding used for secure encrypted communications are first indicated. Then, after a brief recall of the essential points of frequency-agile filters, a second order frequency-hopping bandpass filter operating in current mode and implemented with CCCII is introduced. It necessitates six CCCII only and uses an improved multiple feedback loop connected in such a way that all of its frequency-agile filters of classes 0, 1, 2 and 3 are available. This very low consumption active filter so offers the advantage to have four central frequencies selected digitally for each value of its bias current. Validation results in 0.25 μm SiGe BiCMOS technology are given. They highlight the new perspectives for encrypted communications to be expected from this approach.     

Multistandard transceivers: state of the art and a new versatile implementation for fully active frequency agile filters

The various architectures of transceivers for current standards are firstly compared. Different possibilities to achieve multi-standard transceivers are also recalled and compared. We demonstrate that ease of realization and flexibility evolve in opposite directions. The advantages and drawbacks of reconfigurable active filters are indicated. We demonstrate that the second generation current controlled conveyor operating in current mode is perfectly suitable for the realization of frequency-agile filters. After a brief recall of the essential points of agile filters, a second order frequency agile bandpass filter operating in current mode is implemented with CCCII+ . It has four central frequencies whose values could be selected digitally. The validation results show that its tuning ratio n = f _0max/f _0min is equal to 5.1 with f _0max = 1.22 GHz.     

基于OTA和CCCⅡ实现的n阶多功能滤波器

本文提出了用信号流图法设计n阶基于OTA和CCCⅡ电流模式多功能滤波器的方法。该滤波器由具有双输出端的OTA和CCCⅡ及接地电容构成。适当选定输出电流信号可同时实现低通,高通,带通,带阻以及全通五种滤波功能,而电路内部结构及器件数目无需改变。与同类电路比较,本设计更简便,结构更简单,无源元件全部接地,易于集成。本文还给出了滤波器的设计实例,PSpice仿真结果与理论分析相吻合,验证了该方法的可行性。     

Current-tunable current-mode multifunction filter based on dual-output current-controlled conveyors

In this paper, a current-tunable current-mode multifunction filter with two inputs and two outputs employing only four dual-output current-controlled conveyors (DO-CCCIIs) and two grounded capacitors is proposed. By appropriately connecting the input and output terminals, the proposed circuit can provide lowpass, bandpass, highpass, bandstop and allpass current responses. The filter also offers an independent electronic control of the natural frequency (ω_o) and the quality factor (Q) through adjusting the bias currents of the DO-CCCIIs. No critical matching conditions are imposed for realizing all the filter responses, and all the incremental parameter sensitivities are low. The characteristics of the proposed circuit are simulated using PSPICE to confirm the theory.     

Electronically tunable multifunctional translinear-C filter andoscillator

The current-controlled second order multifunctional filter is described. It uses only three current controlled conveyors and two grounded capacitors. Three types of current transfers, highpass, bandpass, and lowpass, can be acheived simultaneously and both ω0, and Q are electronically adjustable. The circuit can also be modified to be a current controlled oscillator. The simulated results are illustrated     

New current-mode current-controlled universal filter with single input and three outputs

In this study, a new current-mode current-controlled universal filter with single input and three outputs is presented. The proposed circuit uses single-output current controlled conveyors (CCCIIs) and can simultaneously realize lowpass, bandpass and highpass filter functions all at high impedance outputs. Realization of notch and allpass responses does not require additional active elements. The circuit enjoys independent current-control of the parameters ω₀ and ω₀/Q without disturbing the gains of the lowpass, bandpass and highpass filters. Both its active and passive sensitivities are low.     

Current controlled bandpass filter based on translinear conveyors

A new concept to take advantage of the parasitic resistance that appears on port X of the second-generation current conveyors is introduced. This parasitic resistance, which is controllable in current, leads to the definition of the second generation current controlled conveyors (CCCII). A current controlled bandpass filter, operating in the current mode, is also described. It uses only two CCCII's and two capacitors. Its central frequency can be adjusted by acting on the bias current of the conveyors. SPICE simulation results, in agreement with theory, are given for central frequencies around 30 MHz     

基于单CCCII的基带滤波器

本文提出了由单电流控制传输器（current controlled conveyor）实现的新型二阶低通滤波器，该滤波器是交流耦合，结构简单，功耗低，带宽约5MHz，适用于WCDMA的直流变频接收机。     

新型电流控制电流传输器

提出了一种新型电流控制电流传输器(CCCII)电路。该CCCII电路由跨导线性环电路和双极性Wilson电流镜构成。为实现该新型CCCII电路,还提出了双端输出的双极型Wilson电流镜。该CCCII电路具有输出阻抗高、电压及电流传输精度高、易于实现、便于集成等优点。文中分析了电路的工作原理,给出了实验结果,验证了电路的正确性。     

Negative impedance converter with a translinear implementation

A new negative impedance converter circuit, which is a current inversion type (I-NIC), is described. The basic cell consists of a mixed translinear loop comprising two pnp and two npn bipolar transistors. This cell is used in conjunction with a constant current source and two complementary current mirrors. The characteristics and the properties of the practical realization are presented and discussed. A new bandpass filter, which is a current processing circuit, using the I-NIC and a current-controlled current source (CCCS) are also introduced. Experimental results are given.     

Third order voltage mode universal filter using CCCII

This paper brings a multi input single output third order universal filter using second generation current controlled current conveyor (CCCII). The proposed structure consists of three CCCIIs and three capacitors for all filter responses. The universal filter offers all five sections of filter responses, namely: low-pass, high-pass, band-pass, notch filter and all-pass. The topology can provide all filter responses by the proper selection of input. The proposed universal filter offers some important features like no external resistor, minimum number of CCCIIs, no component matching constraint for filter response, electronically adjustable filter response using bias current of CCCIIs and many more. The workability of the proposed structure is well verified with PSPICE in which simulation results follow the theoretical one.