Umut Engin Ayten

Current and voltage transfer function filters using a single active device

In this study, current and voltage transfer function filters using single active component, namely, current backward transconductance amplifier (CBTA) are presented. The proposed structures are a single-input three outputs (SITO) current-transfer function filter, a single-input four-output (SIFO) voltage transfer function filter and three-input single-output (TISO) voltage transfer function filter. The proposed filters have low active and passive sensitivities and use canonical number of electronics components. The validity of the proposed circuits is demonstrated by PSPICE simulations and experimental results. Operation range of the CBTA and its parasitic effects are also discussed.

Component reduced current-mode full-wave rectifier circuits using single active component

This study presents the design of current-mode full-wave rectifier circuits using single active component. The first proposed circuit uses only one operational transconductance amplifier (OTA), two diodes and two resistors. Its current gain can be electronically controlled using the transconductance gain of the OTA. The second proposed circuit uses only one differential voltage current conveyor (DVCC), two diodes and three resistors. Using the complementary metal-oxide semiconductor structure of both OTA and DVCC, the behaviours of the proposed structures have been verified by HSPICE simulations. In addition, both of the proposed circuits are tested practically using commercially available components, such as AD844 and LM13700.

Electronically tunable sinusoidal oscillator circuit with current and voltage outputs

A new circuit configuration for the realisation of an electronically tunable sinusoidal oscillator is presented. The proposed circuit uses only one current backward transconductance amplifier (CBTA), two grounded capacitors and one resistor. Using current controlled CBTA (CC-CBTA) instead of the CBTA, the resistor can be completely removed. It has also current-mode (CM) and voltage-mode (VM) outputs, simultaneously. The workability of the proposed structure has been demonstrated by both simulation and experimental results.

A new compact CMOS realization of sinusoidal oscillator using a single modified CBTA

In this paper, a new compact realization of sinusoidal oscillator using modified current backward transcon-ductance amplifier (MCBTA) is reported. The proposed circuit employs a single MCBTA and four passive components including two grounded capacitors. The circuit provides completely de-coupled condition of oscillation (CO) of the frequency of oscillation (FO), i.e. no term in the CO is present in the FO and vice versa. Both the CO and FO are independently tunable by two different grounded resistors. The FO is also tunable by means of the transconductance and thereby is electronically tunable. SPICE simulation results have confirmed the workability of the proposed circuit.

Novel floating FDNR, inductor and capacitor simulator using CBTA

In this study novel floating frequency dependent negative resistor (FDNR), floating inductor (FI), floating capacitor and floating resistor simulator circuit employing two CBTAs and three passive components is proposed. The presented circuit can realize floating FDNR, inductor, capacitor or resistor depending on the passive component selection. Since the passive elements are all grounded, this circuit is suitable for fully integrated circuit design. The circuit does not require any component matching conditions, and it has a good sensitivity performance with respect to tracking errors. Moreover, the proposed FDNR, inductance, capacitor and resistor simulator can be tuned electronically by changing the biasing current of the CBTA or can be controlled through the grounded resistor or capacitor. The proposed floating FDNR simulator circuit is demonstrated by using a PSPICE simulation for 0.25 μm TSMC CMOS technology.

Application possibilities of VDCC in general floating element simulator circuit

In this study, a low-voltage design of a new general floating element simulator circuit for realizing floating frequency dependent negative resistor (FDNR), floating inductor (FI), floating capacitor (FC), and floating resistor (FR) simulator, depending on the selection of passive circuit elements, is described. The circuit employs two voltage differencing current conveyors (VDCCs) at low voltage levels (±0.45 V) and three passive components. It does not require any passive element matching. Moreover, the new general floating element simulator can be electronically controllable by changing the bias currents of the VDCCs or can be controlled through the grounded resistor or capacitors. Finally, using one of the described floating element simulator, i.e. FDNR, a fourth-order Butterworth characteristic band-pass filter is simulated via PSPICE using 90 nm, level 7 PTM CMOS technology parameters. The simulations agree with the theoretical analysis.

Optimized analog filter approximation via evolutionary algorithms

In this work, fast and efficient evolutionary algorithms, Artificial Bee Colony (ABC), Particle Swarm Optimization (PSO), Differential Evolution (DE), Harmony Search (HS) are used to optimize the denominator coefficients of the low-pass filter transfer function. Optimum selection of the coefficients will approximate the transfer function to ideal characteristic. Three different order of transfer functions are taken into consideration. Compared to conventional methods, all evolutionary algorithms obtain less approximation error in a short computation time.

Design of dominantly proportional PID controller using a single commercially available active component

A proportional integral derivative (PID) controller employing only a single commercially available active component, two resistors and two capacitors is presented. The PID controller circuit has low impedance voltage output which can be easily cascaded with other voltage-mode (VM) structures. The effects caused by the non-ideality of the current feedback operational amplifier (CFOA) are analyzed. The performance of the proposed circuit is demonstrated by using PSPICE simulations.

Current-mode SITO filter using a single active component

In this paper, current-mode filter using new active component, namely; current backward transconductance amplifier (CBTA) is presented. The proposed filter uses two resistors, two capacitors and only one CBTA. It has low active and passive sensitivities. The validity of the proposed circuit is demonstrated by PSPICE simulations and experimental results.

Voltage-mode multiphase sinusoidal oscillators using CBTAs

A voltage-mode multiphase sinusoidal oscillator (MSO) structure using current backward transconductance amplifier (CBTA) is presented. The oscillator can generate n voltage signals (n being even or odd) equally spaced in phase. n+1 CBTAs, n grounded capacitor and a grounded resistor are used for nth-state oscillator. The oscillation frequency can be independently controlled through transconductance (gm) of the CBTAs which are adjustable via bias currents. The effects caused by the non-ideality of the CBTA on the oscillation frequency and condition have been analyzed. The performance of the proposed circuit is demonstrated on a third-stage MSO by using PSPICE simulations based on the 0.25 μm TSMC level-7 CMOS technology parameters.