English title

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In this paper, α and β parameters and gating variables equations of Hodgkin-Huxley neuron cell have been studied. Gating variables show opening and closing rate of ion flow of calcium and potassium in neuron cell. Variable functions α and β, are exponential functions in terms of u potential that have been obtained by Hodgkin and Huxley experimentally to adjust the equations of neural cells. In this study, using FGMOS transistors to model these equations has been reduced cost, complexity, voltage and power. The transistors work in the sub threshold region, hence the proposed circuit consumes less power. Hspice simulation software with 0.18 μ technology has been carried out and silicon area for the designed circuit of gating variables is 115μm×60μm.
 

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A new structure is presented for digital delta-sigma modulator (DDSM). Novel architecture decreases hardware consumption, output quantization noise and spurs in Comparison to previous architectures. In order to reduce the delay, power consumption and increase maximum working frequency, the pipelining technique and the carry skip adder are used. Simulation proposed architecture shows that the quantization noise is declined as 15dB compared to 13-bit conventional third-order modulator. Furthermore, the results of digital implementation report significant reduction in the hardware consumption, the power consumption and increase 3 times in the maximum working frequency.

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In energy supply applications for low-power sensors, there are cases where energy should be transmitted from a low-power battery to an output stage load capacitor. This paper presents an adiabatic charging circuit with a parallel switches approach that connects to a low-power battery and charges the load capacitor using a buck converter which operates in continuous conduction mode (CCM). A gate controller of parallel switches (GCPS) is used to increase the duty-cycle of the input signal of buck converter switches, which controls the inductor current and charges the load capacitor in 256 steps. The proposed parallel switches approach is used to improve the energy efficiency under different powers transmission and comprises a current sensor, comparator, R-S latch, parallel pMOS switches, and parallel nMOS switches. For high powers transfer, the large switches are paralleled with small switches and result in conduction losses reduction. Also, for low powers transfer, the total switching losses are significantly reduced by turning off the large PMOS/NMOS switches during the charging operation. The proposed circuit was designed and simulated in a 0.18μm CMOS technology. The efficiency of the proposed circuit during the capacitor charge-up cycle is more than 80% for average input powers between 0.5mW to 30mW.

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A DC-DC converter with a quasi-active switched-inductor structure for renewable energy systems is introduced in this paper. In the presented structure, the switched inductor method is integrated with the coupled inductor. The proposed converter consists of four capacitors, four diodes, two active switches and two coupled inductors derived from the switched inductor network and can be integrated into one magnetic core. The primary side of the coupled inductors are charged/discharged in parallel/series by the input source. Two sets of diode-capacitor, in addition to increasing the voltage conversion ratio, reduces the voltage jump caused by the leakage inductor, as a result, the voltage stress on the power switches is limited. Therefore, two switches with low conduction resistance can be used to reduce conduction losses, thus increasing efficiency. Also, two diodes do not have the problem of reverse recovery due to turn off naturally, the reverse recovery problem of the output diode is also reduced by the leakage inductor. Operating principles and steady state analysis are discussed in detail. Then, the performance of the proposed converter is compared with existing converters. Finally, a laboratory prototype was created and experimental results are presented to verify its performance.