The Effects of Non-Idealities and Current Limitations on the Simulated Inductances Employing Current Conveyors

Active devices such as current conveyors play an essential role on the performance of simulated inductances. The effects of second-generation current conveyor (CCII) non-idealities on the proposed and on the previously published inductances are investigated, in which lossless inductances are realized. CCIIs like all active devices have terminal current limitations that can not be exceeded. Thus, the values of the applied input current sources for the proposed and previously published inductances depending on the passive elements values and applied signal frequency impose restrictions on the input current of the inductor. Erkan Yuce was born in 1969 in Nigde, Turkey. He received the B.Sc. degree from Middle East Technical University and M.Sc. degree from Pamukkale University in 1994 and 1998 respectively, all in Electrical and Electronics Engineering. He is currently Research Assistant and a Ph.D. student at the Electrical and Electronics Engineering Department of Bogazici University. His current research interests include analog circuits, active filters, synthetic inductors, voltage-mode current-mode circuits. He is the author or co-author of about 4 papers published in scientific journals or conference proceedings Oguzhan Cicekogluwas born in 1963 in Istanbul, Turkey. He received the B.Sc. and M.Sc. degrees from Bogazici University and the Ph.D. degree from Istanbul Technical University all in Electrical and Electronics Engineering in 1985, 1988 and 1996 respectively. He served as lecturer at the School of Advanced Vocational Studies Electronics Prog. of Bogazici University where he held various administrative positions between 1993 and 1999, and as part time lecturer at various institutions. He was with Biomedical Engineering Institute between 1999 and 2001. He is currently Associate Professor at the Electrical and Electronics Engineering Department of Bogazici University. His current research interests include analog circuits, active filters, analog signal processing applications and current-mode circuits. He is the author or co-author of about 150 papers published in scientific journals or conference proceedings. Oguzhan Cicekoglu is a member of the IEEE.     

Differential voltage current controlled current conveyor with low-voltage operation capability

A novel differential voltage current controlled current conveyor topology is introduced in this article. It has the capability for operating in a low-voltage power supply environment and, also, offers resistorless filter realisations. The main attractive offered benefit is that the handling of AC signals is exclusively performed by nMOS transistors and, thus, the proposed element has capability for high-frequency operation. The performance of the proposed cell has been experimentally verified through the realisation of two 3rd-order filters, derived according to the leapfrog and component substitution methods. The filter topologies have been fabricated through the AMS 0.35 µm CMOS process.     

Insensitive voltage-mode and current-mode filters with easily modifiable transfer functions

Two configurations for 2^nd order current-mode filters are introduced. The circuits, which exhibit low values for their active and passive sensitivies are implemented from two current conveyors. They are easily cascadable because they exhibit zero input impedance. Two voltage-mode implementations are then deduced from them. Depending on the passive components used, the circuit will be either a 2^nd order or a 3^rd order filter. Both the current-mode and voltage-mode implementations are characterized by easily modifiable transfer functions, without affecting ₀ and Q.SPICE simulation results, which confirm the theoretical analysis, are given and discussed for current conveyors implemented in a translinear form.     

Sinh-Domain linear transformation filters

A new systematic method for designing Sinh-Domain linear transformation (LT) filters is introduced in this article. For this purpose, a substitution scheme containing the Sinh-Domain LT equivalent of each passive prototype has been introduced. The proposed equivalents have been realised by employing appropriate Sinh-Domain building blocks with low-voltage operation capability. As an example, a third-order Sinh-Domain elliptic LT filter has been designed and its performance has been evaluated through simulation results. In addition, a detailed comparison with the corresponding Sinh-Domain and log-domain counterparts has been performed and the obtained results have been further discussed.     

FDCCII-based FDNR simulator topologies

In this article, three new circuits for realising frequency-dependent negative resistance (FDNR) are proposed. All proposed circuits employ a single fully differential current conveyor, grounded capacitors and resistor. Proposed circuits consist of minimum number of passive and active elements. All proposed circuits are lossless FDNR. The performance of the proposed FDNR is demonstrated on the third-order Butterworth low-pass filter. Simulation results are included to verify the theory.     

Single MIMO-OTA and single-grounded-capacitor-based first-order allpass filter design

A novel first-order voltage-mode allpass (AP) filter employing a single multiple-input-multiple-output operational-transconductance-amplifier (MIMO-OTA) and a single grounded capacitor is introduced in this article. Compared to the corresponding already published topologies, the offered benefits are as follows: it employs minimum number of active and passive components; the only capacitor is grounded, which is good for a monolithic integration of an IC; and the absence of any matching condition for its realisability. The performance of the proposed circuit has been evaluated through simulation results, utilising the analogue design environment of Cadence software.     

A New Transadmittance Type First-Order Allpass Filter Employing Single Third Generation Current Conveyor

A novel transadmittance (TA) mode first-order all-pass filter configuration is proposed. The proposed circuit uses a third generation current conveyor (CCIII), three resistors and a grounded capacitor. The output of the filter exhibits high output impedance so that the synthesized filter can be cascaded without additional buffers. The theoretical results are verified with PSPICE simulations using a CMOS realization of CCIII.     

CMOS电流控制全平衡式电流传输器

This paper presents a current controlled fully balanced second-generation current conveyor circuit（CF-BCCII）.The proposed circuit has the traits of fully balanced architecture, and its X-Y terminals are current control-lable.Based on the CFBCCII, two biquadratic universal filters are also proposed as its applications.The CFBCCII circuits and the two filters were fabricated with chartered 0.35-μm CMOS technology;with ±1.65 V power supply voltage, the total power consumption of the CFBCCII circuit is 3.6 mW.Comparisons between measured and HSpice simulation results are also given.     

具有高频补偿的CMOS MOCCII

为了使MOCCII(多端输出的第二代电流传输器)能工作于高频段,本文提出了一种具有高频补偿的CMOS MOCCII电路.对于电流传输函数I_Z/I_X及,I_(Z-)/I_X采用在电流镜中加一个可调电阻方法,使得电流镜的传输函数由一阶系统变成可调极点的二阶系统,调节电阻大小,使得极点远离S平面原点,从而提高电流镜频带宽度.对于电压传递函数V_X/V_Y,在X与Y之间加并行差分对,以增加等效跨导,提高V_X/V_Y的频带宽度,同时,在X与Y之间的负载电流镜中加入一个电阻,以进一步提高VX/VY的频带宽度.仿真表明,V_X/V_Y的-3dB截止频率由补偿前的544MHz提高到补偿后的1.053GHz;I_Z/I_X及I_(Z-)/I_X的-3dB截止频率分别由补偿前的510MHz、400MHz提高到补偿后的1GHz.最后,作为应用,给出了由补偿前后MOCCII所构成的电流模式滤波器.     

High-Speed High-Precision CMOS Current Conveyor

In this paper a new class-AB CMOS second generation current conveyor (CCII) based on a novel high-performance voltage follower topology is proposed. Post-layout simulation results from a 0.8 m design supplied at 3.3 V show very low resistance at node X (<50 ), high frequency operation (100 MHz), high precision in the voltage and current transference and reduced offset. As application examples, a V-I converter and a current feedback operational amplifier (CFOA) have been implemented. The latter presents slew-rate levels higher than ±100 V/s.     

IC Voltage to Current Transducers with Very Small Transconductance

This paper deals with the design of very small ac transconductance voltage to current transducers intended for the design of low frequency continuous-time filters, very large resistors and other applications. The first type of Operational Transconductance Amplifiers (OTA) is based on a triode biased transistor and a current division technique. The second one uses partial positive feedback which allows to reduce transistor dimensions but the sensitivity to transistor mismatches increases. The proposed techniques can be used for the design of high-order low frequency IC filters, ladder or based on biquads, with moderated transistor dimensions while the dynamic range-cutoff frequency performance is comparable to previously reported structures. A 10 Hz third order lowpass ladder filter has been designed with these techniques, and it shows a dynamic range of 62 dB. Besides, a novel biasing technique for capacitive sources coupled preamplifiers is proposed. Experimental results for a prototype, fabricated in a 1.2 m 1 level below 15 _RMS and dynamic range of 63 dB. The power consumption is only 10 watts and the supply voltages are ± 1.5 volts.     

Switched-Current Wave Filters with Reduced Number of Current Inversions

Switched-current wave filters offer very simple structures, as their main building blocks are current mirrors. On the other hand, the achieved accuracy is mainly degraded due to the effect of MOS transistor parameters mismatch. In this Letter, new configurations of serial and parallel adaptors that are used in the simulation of inductances and capacitors of the LC ladder prototype are introduced. These have been implemented using an appropriate sharing of the delay that should be presented between the incident and reflected waves at a port of adaptor, and a 3-phase clocking scheme. The number of required current inversions and consequently the effect of mismatching are reduced in the proposed configurations.     

基于CCⅡ多输入单输出电流模式滤波器

为了实现结构简单、便于集成的三输入单输出电流模式滤波器,提出了三输入单输出电流模式滤波器的信号流图。用CCⅡ（第二代电流传输器）及多端输出的电流镜实现了该信号流图,得到一个由CCⅡ及电流镜共同构成的电流模式滤波器。该滤波器由2个CCⅡ、1个三端输出的电流镜及4个RC元件构成,能方便地实现5种滤波器输出。该滤波器可用于通信、电子测量与仪器仪表中的信号处理。硬件实验结果表明提出的电路是正确的。