One of the most widely used current mode circuits is the current conveyor circuit, so that after current mirrors, they are the most commonly used circuits in the analog field. The ability to process voltage and current at the same time, more bandwidth, gain more bandwidth and gain independence form bandwidth, are notable features of this circuit. In this article, we have designed a logarithm circuit with flow conveyors based on flow theory, so that while eliminating the defects of previous circuits, we can also have innovations in the design of a logarithm circuits. Presenting a new method for designing logarithmic circuit based on current mode, using current conveyors to design logarithmic circuit, using low power and voltage circuits, circuit design with temperature independent output and thus more stability are the results of this article. In this new method, relying on the mathematical relations that lead to the natural input logarithm, a new logarithm circuit is designed. Design of the new logarithm circuit is done in 180 microwatt technology, in the current mode. The current consumption of the circuit is about 5.96 µA, the power consumption is 2.98 µW, the gain is 69.7 dB and bandwidth is about 85 kHz. The correct operation of the designed circuit has been investigated by simulation in HSPICE and MATLAB software.

Realization of a novel single-resistance-controlled oscillator, employing an active element and all grounded passive elements, is the purpose of this manuscript. With requirements for completing the design being only a single Voltage Differencing current conveyor and four grounded passive components, it is also a preferable choice for integrated circuit implementation. The designed circuit has an independent control of the frequency of oscillation and current mode output can be achieved from high impedance port, explicitly. Simulation results are presented using PSPICE software along with the regular mathematical analysis. At last experimental verification of the proposed circuit is shown using commercially available integrated circuits.

Design and construction of a stable current supply with protection circuits are described. The reported circuit provides a high-stable and high-level current variable from 0.5 -1.2 A with the protection circuits to prevent overload current, voltage and off-range temperature operation. A detailed analysis of the circuit parameters is given and the time behaviors of the load voltage/current and shut -off voltage/current are presented. Theoretical analysis shows a turn-on time of about 20 ns for the load current and a shut-off time of about 150 ns. The proposed scheme is verified both by simulation and by constructing a prototype. The prototype version of this circuit shows a good stability in load current, and the laser diode temperature can be monitored with an accuracy of about 1 degree. In addition, design and analysis of the current modulator and switching circuits for laser diodes are reported. Modulation process and different modulation techniques are explained in detail. Drive circuits for positive and negative intensity modulation are presented. Transient analysis for the proposed drivers is performed by using PSPICE software and the results are reported here. Evaluation of the results indicates that the reported modulators can be used successful1y for direct current modulations.

This article reports on the design of a 8-channel neural recording amplifier and stimulation back-end in TSMC 0. 18μ m technology which can do the recording and stimulating simultaneously. The design of proposed neural amplifier is based on indirect negative feedback and provides tunable lower cutoff frequency, and digitally-programmable upper cutoff frequency and voltage gain. Moreover, the proposed circuit employs attenuators in the same feedback loop in order to further reduce the silicon area consumed by the capacitors and at the same time to increase the input impedance of the circuit. The 8-channel designed circuit consumes 0. 27mm2 of chip area and operated with a supply voltage of 1. 8V, power consumption of each channel is 27μ W with the THD of-50dB@1kHz and output voltage swing of 0. 95Vpp. The designed stimulation bak-end circuit, in addition to traditional rectangular pulse shapes, can generates biphasic stimulation pulses with exponential shapes, whose time constants are digitally programmable. A class-B second generation current conveyor is designed to be used for delivering stimulation current pulses of up to ± 96μ A to the target tissue and a charge pump block is in charge of the generating supply voltages of ± 3. 3V. The circuit consumes 0. 043mm2 of silicon area for each channel (excluding charge pumps). Simulation results indicate that the stimuli generator meets expected requirements with the maximum power consumption of 1. 2mW when connected to electrode-tissue impedance of as high as 25kΩ .

A generalization method is used to transform a floating resistor oscillator circuit to a family of sixteen grounded capacitor oscillators using the current conveyor (CCII) or the inverting current conveyor (ICCII) or combination of both. Two of the oscillator circuits have a floating property. A new family of sixteen oscillator circuits is generated from the known circuit using the adjoint circuit theorem. It is also shown that the oscillator under consideration leads to the generation of other known and new grounded passive element oscillators employing the differential voltage current conveyor (DVCC) and the balanced output current conveyor (BOCCII).

A High-gain, fully balanced preamplifier is presented. The proposed structure advantages flipped voltage follower scheme to achieve a compact current conveyor with very low input impedance. The presented current conveyor then is used as a core element to realize a high-gain, gm-enhanced trans-conductance amplifier. The presented amplifier is suitable for application as a preamplifier. The high gain of amplifier makes it very suitable to be configured in a feedback form to deliver a high-precision predefined or programmable amplification gain. The proposed structure draws a very low power of 150nW from a 0.6V supply voltage. The Spectre Post-layout simulations with TSMC 180nm CMOS technology have been performed. The proposed amplifier exhibits an open-loop DC gain of 141.5dB and 3-dB frequency bandwidth of 2.4kHz at 60dB closed-loop configuration. The load capacitance is set to be 5pF. The proposed structure also delivers high CMRR and PSRR values of 148.3dB and 153.7dB, respectively.

In this paper, the transistor level of single-ended and differential low-power sample-hold is presented based on carbon nanotube field effect transistor technology using the advantages of second generation current conveyor blocks. The switching operation in the proposed sampl and holds is based on the structure of the second generation current conveyor, which means that it has the same function as the analog current-conveyor switches.The implementation of the proposed the sample and hold blocks with using advantages of carbon nanotube field effect transistors improves the performance sampl and hold circuit. The proposed sample and hold circuits have very low power consumption and high operating speed, and it also does not require a non-overlapping clock pulse signal. These proposed circuits have been implemented and simulated in HSPICE software using 32-nanometer carbon nanotube field effect transistor technology. The simulation results show that the power consumption of the differential sample and hold circuit is 13.45 μW, also the ENOB value of the differential sample and hold circuit for the sampling frequency of 2 GHz and the input frequency of 20 MHz is 11 bits. The FOM index of the proposed circuit is 0.61×10-6 (nJ/Bit.Samples).

This paper introduces four new resistorless circuits of first-order current-mode all-pass filter (CMAPF) based on dual-X current conveyor transconductance amplifier (DXCCTA). All the four circuits use a single DXCCTA and a capacitor for their realization. The main features of the proposed CMAPFs are: use of minimum active and passive components, resistorless realization, electronically adjustable pole frequency, easily cascadable, good sensitivity performance with respect to active and passive elements, low total harmonic distortion of output current (0. 74%) and good operating frequency range (39. 2 MHz). The non-ideal analysis of the proposed circuits has also been explored. Moreover, two applications of the proposed first-order CMAPF in terms of second order CMAPF and current-mode quadrature oscillator are also presented. HSPICE simulations have been carried out with 0. 18 μ m CMOS process parameters to validate the proposed circuits.

Carbon Nanotube Field Effect Transistors (CNFET) are considered to be the potential candidates for overcoming the shortcomings associated with the scale of the art CMOS transistors; as the scaling continues. In this paper a digitally reconfigurable CNFET based biquadratic multifunctional filter employing a CNFET based single Differential Voltage current conveyor (DVCC) at 32nm technology node has been presented. The circuit utilizes a single CNFET based DVCC block along with the arrangement of few resistors and capacitors. The proposed digitally reconfigurable multifunctional filter circuit is able to obtain programmable low pass, high pass and band pass filter configurations using the same topology. The designed CNFET based multifunctional filter obtains a resonant frequency of the order of GHz. Furthermore, a 3-bit digital control of the designed multifunctional filter parameters i.e. Quality Factor (Qo) & resonant frequency has been made possible using the current Summing Network (CSN). Sensitivity and comparative analysis has also been performed. The circuit has been simulated at a low voltage supply of 0.9V using HSPICE environment at 32nm technology node. The simulation results obtained are in sync with the theoretical analysis