Hamiltonian energy and coexistence of hidden firing patterns from bidirectional coupling between two different neurons

In this paper, bidirectional-coupled neurons through an asymmetric electrical synapse are investigated. These coupled neurons involve 2D Hindmarsh–Rose (HR) and 2D FitzHugh–Nagumo (FN) neurons. The equilibria of the coupled neurons model are investigated, and their stabilities have revealed that, for some values of the electrical synaptic weight, the model under consideration can display either self-excited or hidden firing patterns. In addition, the hidden coexistence of chaotic bursting with periodic spiking, chaotic spiking with period spiking, chaotic bursting with a resting pattern, and the coexistence of chaotic spiking with a resting pattern are also found for some sets of electrical synaptic coupling. For all the investigated phenomena, the Hamiltonian energy of the model is computed. It enables the estimation of the amount of energy released during the transition between the various electrical activities. Pspice simulations are carried out based on the analog circuit of the coupled neurons to support our numerical results. Finally, an STM32F407ZE microcontroller development board is exploited for the digital implementation of the proposed coupled neurons model.

Modified Gorski-Popiel Technique and Synthetic Floating Transformer Circuit Using Minimum Components

The aim of this paper is proposing an alternative method to Gorski-Popiel Technique in realization of synthetic transformers. A new synthetic floating transformer (FT) circuit is also given. The proposed synthetic transformer circuit uses two current backward transconductance amplifiers (CBTAs), three resistors, and two grounded capacitors. The primary self-inductance, the secondary self-inductance, and the mutual inductance can be independently controlled and can be tuned electronically by changing the biasing current of the employed CBTAs. It has a good sensitivity performance with respect to tracking errors. A band-pass filter is also realized to test the performance of the proposed synthetic transformer circuit. The validity of the proposed synthetic transformer circuit is demonstrated by PSPICE simulations and experimental results.

CDBA based current instrumentation amplifier

This paper presents a novel method to realize a current mode instrumentation amplifier (CMIA) through CDBA (Current difference Buffered Amplifier). It employs two CDBAs and two resistors to obtain desired functionality. Further, it does not require any resistor matching. The gain can be set according to the resistor values. It offers high differential gain and a bandwidth, which is independent of gain. The working of the circuit is verified through PSPICE simulations using CFOA IC based CDBA realization.

All Pass Network Based MSO Using OTRA

This paper presents multiphase sinusoidal oscillators (MSOs) using operational transresistance amplifier (OTRA) based all pass networks. Both even and odd phase oscillations of equal amplitudes which are equally spaced in phase can be produced using single all pass section per phase. The proposed MSOs provide voltage output and can readily be used for driving voltage input circuits without increasing component count. The effect of nonideality of OTRA on the circuit performance is also analysed. The functionality of the proposed circuit is verified through PSPICE simulations.

Transadmittance Type Universal Current-Mode Biquad Filter Using VDTAs

A new resistorless single-input-multi-output (SIMO) universal transadmittance (TA) type filter employing two voltage differencing transconductance amplifiers (VDTA) and two grounded capacitors is proposed. The proposed topology realizes simultaneously low pass (LP), high pass (HP), and band pass (BP) filter functions. Band rejects (BR) and all pass (AP) filters are also realizable through appropriate connections of currents. The proposed configuration also offers independent control of natural angular frequency (ω0) and bandwidth (BW) and low active and passive sensitivities. The workability of proposed configuration has been demonstrated through PSPICE simulations with TSMC CMOS 0.18 μm process parameters.

Single-Resistance-Controlled Quadrature Oscillator Using CFOAs for GMI Magnetic Sensors

A class of single-resistance-controlled (SRC) quadrature sinusoidal oscillator using CFOAs for GMI magnetic sensors is presented in this paper. By means of state variable, the proposed circuits are designed and analyzed which has the advantages such as noninteractive control of the oscillation condition (CO) and the oscillation frequency (FO), good sensitivity performance and minimum components including grounded capacitors. Moreover, the workability of the proposed circuit has been verified by PSPICE simulations.

Additional High Input Low Output Impedance Analog Networks

This paper presents some additional high input low output impedance analog networks realized using a recently introduced single Dual-X Current Conveyor with buffered output. The new circuits encompass several all-pass sections of first- and second-order. The voltage-mode proposals benefit from high input impedance and low output impedance. Nonideality and sensitivity analysis is also performed. The circuit performances are depicted through PSPICE simulations, which show good agreement with theory.

NOVEL VOLTAGE-MODE CASCADABLE ALL-PASS SECTIONS EMPLOYING GROUNDED PASSIVE COMPONENTS

This paper presents two new first-order voltage-mode (VM) cascadable all-pass (AP) sections, employing two differential voltage current conveyors (DVCCs) and three grounded passive components. Both circuits possess high input and low output impedance, which makes them easily cascadable. Non-ideality aspects and parasitic effects are also studied. As an application, a quadrature oscillator is designed using the proposed circuit. The proposed circuits are verified through PSPICE simulations using 0.5 μm CMOS parameters.

Fractional Resonance-BasedRLβCαFilters

We propose the use of a fractional order capacitor and fractional order inductor with orders0≤α, β≤1, respectively, in a fractionalRLβCαseries circuit to realize fractional-step lowpass, highpass, bandpass, and bandreject filters. MATLAB simulations of lowpass and highpass responses having orders of(α+β)=1.1, 1.5, and 1.9 and bandpass and bandreject responses having orders of 1.5 and 1.9 are given as examples. PSPICE simulations of 1.1, 1.5, and 1.9 order lowpass and 1.0 and 1.4 order bandreject filters using approximated fractional order capacitors and fractional order inductors verify the implementations.