On the Resistorless Realization of Simulated Tunable Floating Lossy Inductors with Voltage Differencing Buffered Amplifiers

Journal of Communications Technology and Electronics - Alternative circuit designs concerning the simulation of floating lossy inductors using voltage differencing buffered amplifiers (VDBAs) are...     

Structural generation of two integrator loop filters using CDTAs and grounded capacitors

A versatile family of two integrator loop filter structures using current differencing transconductance amplifiers (CDTAs) and grounded capacitors is generated. The basic filter building blocks consist of current proportional blocks, current lossless integrators and a current lossy integrator based on the use of CDTAs as the major active components. It is demonstrated that the derived filter structures can realize a general class of second‐order current transfer functions. Since the resulting structures contain only CDTAs and grounded capacitors, they are general and very appropriate for integration, cascading and electronic tuning. The influences of the CDTA non‐idealities are also discussed. The functionality of the resulting filters has been verified by simulation results. Copyright © 2009 John Wiley & Sons, Ltd.     

Compact VDTA-based current-mode electronically tunable universal filters using grounded capacitors

This paper presents a compact current-mode three-input single-output (TISO) type universal filter. Only one voltage differencing transconductance amplifier (VDTA) and two grounded capacitors are employed in the proposed filter. The circuit can realize lowpass, bandpass, highpass, bandstop and allpass biquadratic filter outputs by connecting the appropriate inputs, and offers electronic control of the natural angular frequency (ω₀) and quality factor (Q) by means of adjusting the transconductance gain of the VDTA. In addition, by slight modification of the proposed scheme, another more useful TISO construction with orthogonal ω₀–Q tuning has been obtained. Both the discussed universal filters have been shown to have low incremental active and passive sensitivities. To demonstrate the performances of the filters and verify the theoretical analysis, computer simulations are accomplished with the PSPICE program.     

Electronically Tunable Current-Mode Universal Filter Employing Only Plus-Type Current-Controlled Conveyors and Grounded Capacitors

A new current-mode current-controlled three-input single-output universal filter, which employs only five plus-type second-generation current-controlled current conveyors (CCCIIs) and two grounded capacitors, is presented in this paper. The proposed configuration provides lowpass, bandpass, highpass, bandstop, and allpass current responses at a high impedance terminal, which enables easy cascadability of the circuit. The filter also offers independent electronic control of the natural frequency ω_o and the quality factor Q through adjusting of the bias current of the CCCII. Derived analytical expressions for the filter parameter deviations due to CCCII nonidealities are also included. PSPICE simulation results are performed to confirm the theoretical analysis.     

Sinusoidal frequency doubler and full-wave rectifier based on translinear current-controlled current conveyors

A circuit design technique that employs translinear current-controlled current conveyors as active circuit elements to design a sinusoidal frequency doubling and full-wave rectifying circuit is proposed. The circuit can realize the sinusoidal frequency doubler and full-wave rectifier without changing the circuit configuration. The proposed frequency doubling and rectifying action is exploited from the translinear characteristic of the current conveyor. Simulation and experimental results are given to confirm the theoretical predictions.     

Electronically Tunable Single-Input Five-Output Voltage-Mode Universal Filter Using VDTAs and Grounded Passive Elements

This paper presents a possible usage of the voltage differencing transconductance amplifier (VDTA) for the design of an electronically tunable single-input five-output voltage-mode universal filter. The presented filter is constructed using two VDTAs, two capacitors and two resistors that are all grounded. The circuit simultaneously realizes lowpass (LP), bandpass (BP), highpass (HP), bandstop (BS) and allpass (AP) filtering responses, without changing the circuit topology. The circuit is capable of providing an independent electronic control of the natural angular frequency (ω ₀) and the quality factor (Q) through the transconductance gains of the VDTAs. By simply adjusting the transconductance ratio, a high-Q filter can also be obtained. Because of the high-input impedance of the circuit, it is advantageous for cascade connection. To support the theoretical analysis, the properties of the designed filter have been verified by PSPICE simulation results.     

Voltage-mode universal filter with one input and five outputs using DDCCTAs and all-grounded passive components

This paper presents a versatile voltage-mode universal active filter with one input and five output terminals. The proposed circuit is based on using the recently reported active building block, namely differential difference current conveyor transconductance amplifier (DDCCTA). It employs two DDCCTAs as active elements together with two resistors and two capacitors as passive elements, which are all grounded. The circuit simultaneously realizes all the five standard biquadratic filter functions; i.e., lowpass (LP), bandpass (BP), highpass (HP), bandstop (BS) and allpass (AP), without changing circuit topology. The proposed circuit also has the advantage of high-input impedance terminal, and exhibits electronic tunability of its important parameters through the bias current of the DDCCTA as well as low sensitivity performance. PSPICE simulations using 0.5 μm MIETEC CMOS process are used to validate the theoretical predictions.     

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.