Shahram Minaei

A new CMOS electronically tunable current conveyor and its application to current-mode filters

In this paper, a new CMOS high-performance electronically tunable second-generation current conveyor (ECCII) is presented. The current gain of the proposed ECCII can be controlled electronically by adjusting the ratio of dc bias currents of the ECCII. The output terminal of the proposed ECCII has high impedance, which enables easy cascadability. Also, as an application, the proposed ECCII is used for realizing a universal current-mode filter. The filter realizes low-pass, bandpass, and high-pass responses simultaneously. The low-pass response is obtained at high impedance output and its gain can be independently tuned by changing the current gain of the relevant CC. SPICE simulation results using TSMC 0.35-/spl mu/m CMOS process model shows excellent performance for the proposed ECCII. The proposed circuit consumes average power of 6.6 mW using /spl plusmn/1.5-V supply voltages.

A Modified CFOA and Its Applications to Simulated Inductors, Capacitance Multipliers, and Analog Filters

In this paper, using a minimum number of passive components, i.e., new grounded and floating inductance simulators, grounded capacitance multipliers, and frequency-dependent negative resistors (FDNRs) based on one/two modified current-feedback operational amplifiers (MCFOAs), are proposed. The type of the simulators depends on the passive element selection used in the structure of the circuit without requiring critical active and passive component-matching conditions and/or cancellation constraints. In order to show the flexibility of the proposed MCFOA, a single-input three-output (SITO) voltage-mode (VM) filter, two three-input single-output (TISO) VM filters, and an SITO current-mode (CM) filter employing a single MCFOA are reported. The layout of the proposed MCFOA is also given. A number of simulations using the SPICE program and some experimental tests are performed to exhibit the performance of the introduced structures.

Novel Voltage-Mode All-Pass Filter Based on Using DVCCs

In this paper, a novel design for realizing a voltage-mode (VM) all-pass filter utilizing two differential voltage current conveyors (DVCCs) is proposed. Also, the suggested filter uses a canonical number of passive elements (one grounded capacitor and one resistor) without requiring any element matching condition. The proposed filter has high input and low output impedances, which make it suitable for cascading. The effects of the nonidealities of the DVCCs on the proposed design are investigated. As an application, a quadrature oscillator is designed using the proposed VM all-pass filter and an integrator. The proposed filter and oscillator circuits are simulated using the SPICE simulation program to confirm the theory.

General configuration for realizing current-mode first-order all-pass filter using DVCC

In this paper, a new general configuration for realizing current-mode all-pass filter circuits using differential voltage current conveyor (DVCC) is proposed. The proposed configuration is composed of a DVCC and five passive admittances. However, each of the circuits extracted from the proposed configuration uses only three passive elements. As an application, the proposed configuration is used to construct a quadrature oscillator. The theoretical results are verified by SPICE simulations.

Limitations of the Simulated Inductors Based on a Single Current Conveyor

In this paper, a new simulated inductor employing two resistors, one capacitor, and only a single gain-variable third-generation current conveyor (GVCCIII) is proposed. To exhibit the performance of the proposed simulated inductor, it is used in a parallel R-L-C current-mode filter. The frequency-dependent nonideal voltage gain effects of the GVCCIII on the proposed inductor are given. The low- and high-frequency limitations of the simulated inductor are investigated in detail. The simulations performed with the SPICE program agree with the theoretical analysis. Also, the proposed circuit is tested experimentally using commercially available active devices (AD844 ICs of Analog Devices) to confirm the theory

Full-wave rectifier realization using only two CCII+s and NMOS transistors

In this paper, a voltage-mode full-wave rectifier employing plus-type second-generation current conveyors (CCII+s) and enhancement-mode n-channel metal-oxide semiconductor field-effect transistors (MOSFETs) is proposed. The presented circuit requires no passive components, and is suitable for high frequency applications. The proposed full-wave rectifier circuit is simulated using HSPICE to verify the theoretical analysis.

A Resistorless realization of the first-order all-pass filter

All-pass filters are widely used to shift the phase of an analog signal without altering its magnitude. In this study, a new realization of all-pass filter using one current controlled conveyor (CCCII), one operational amplifier (OP-AMP) and two capacitors is presented. The proposed circuit does not use any resistors thus it is suitable for easy integration. Also the pole frequency of the proposed circuit can be tuned electronically. Simulation results are included to verify theory.

All-Grounded Passive Elements Voltage-Mode DVCC-Based Universal Filters

In this paper two new voltage-mode (VM) universal filters employing three plus-type differential voltage current conveyors (DVCC+s) and grounded passive elements are presented. The first proposed filter is a single-input five-output (SIFO) circuit which can realize simultaneously all of the standard responses, i.e. low-pass (LP), band-pass (BP), high-pass (HP), all-pass (AP) and notch (NH) from the same configuration. The second proposed circuit is a three-input single-output (TISO) universal filter for realizing standard responses depending on the selection of the input signal from the same topology. Both of the proposed filters have the advantage of a high input impedance, which enables easy cascading to obtain higher order filters. The proposed filters are simulated using the SPICE program to verify the theoretical analysis.

A new full-wave rectifier circuit employing single dual-X current conveyor

In this study, a novel voltage-mode full-wave rectifier with high-input impedance using a dual-X second-generation current conveyor and three enhancement-type n-channel metal-oxide semiconductor field-effect transistors (MOSFETs) is introduced. The proposed circuit does not employ any passive elements, and is simulated using SPICE program with level 49, 0.25 µm TSMC CMOS technology parameters to confirm the theory and exhibit the performance of the circuit.

Electronically tunable, active only floating inductance simulation

In this paper a new floating inductance simulator employing only active elements is proposed. The proposed circuit uses one internally compensated operational amplifier and one dual output current controlled conveyor (CCCII). The simulated inductance value can be controlled electronically by adjusting the bias current of the CCCII. No component matching constraints are imposed for the simulator and all active sensitivities are low. The performance of the circuit is demonstrated on a fourth-order elliptic filter using a SPICE simulation program