High Speed Power Efficient CMOS Inverter Based Current Comparator in UMC 90 nm Technology

A novel power-speed efficient current comparator is proposed in this paper. It comprises of only CMOS inverters in its structure, employing a simple biasing method. The structure offers simplicity of design. It posesses the very desirable features of high speed and low power dissipation, making this structure a highly desirable one for various current mode applications. The simulations have been performed using UMC 90 nm CMOS technology and the results demonstrate the propagation delay of about 3.1 ns and the average power consumption of 24.3 µW for 300 nA input current at supply voltage of 1V

Modelling and Design of Inverter Threshold Quantization based Current Comparator using Artificial Neural Networks

Performance of a MOS based circuit is highly influenced by the transistor dimensions chosen for that circuit. Thus, proper dimensioning of the transistors plays a key role in determining its overall performance.  While choosing the dimension is critical, it is equally difficult, primarily due to complex mathematical formulations that come into play when moving into the submicron level. The drain current is the most affected parameter which in turn affects all other parameters. Thus, there is a constant quest to come up with techniques and procedure to simplify the dimensioning process while still keeping the parameters under check. This study presents one such novel technique to estimate the transistor dimensions for a current comparator structure, using the artificial neural networks approach. The approach uses Multilayer perceptrons as the artificial neural network architectures. The technique involves a two step process. In the first step, training and test data are obtained by doing SPICE simulations of modelled circuit using 0.18μm TSMC CMOS technology parameters. In the second step, this training and test data is applied to the developed neural network architecture using MATLAB R2007b

On the occurrence of feulgen positive nucleoli in adrenocortical cells of the pigeon

This article does not have an abstract

Role of B-ring of colchicine in its binding to Zn(II)-induced tubulin-sheets

Colchicine-tubulin dimer complex, a potent inhibitor of normal microtubule assembly undergoes extensive self-assembly in the presence of 1 X 10-4 M zinc sulphate. Polymers assembled from colchicine-tubulin dimer complexes are sensitive to cold. Although colchicine can be accomodated within the polymeric structure, the drug cannot bind to tubulin subunits in the intact polymers. This is evidenced by the fact that (a) the colchicine binding activity of tubulin is lost when allowed to polymerize with zinc sulphate, (b) the loss in colchicine binding could be prevented by preincubation of tubulin with 1 X 10-3 M CaCl2 or 1 X 10-5 M vinblastine sulphate and finally (c) no loss in colchicine binding activity is found when tubulin is kept at a concentration far below the critical concentration for polymerization. Unlike colchicine, its B-ring analogues desacetamido colchicine (devoid of the B-ring subtituent) and 2-methoxy-5-(2', 3', 4'-trimethoxyphenyl) tropone (devoid of the B-ring) can bind to tubulin subunits in the intact polymers. Thus we conclude that the colchicine binding domain on the tubulin molecule is mostly (if not completely) exposed in the Zn(II) -induced polymers and the B-ring substituent plays a major role in determining the binding ability of a colchicine analogue to tubulin in the intact Zn(II) -induced sheets

Tubulin and its assembly promoting factor(s) during maturation of avian erythrocytes

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The Design of a High Speed Nonlinear Feedback-based Current Comparator

In this paper a new current comparator architecture is presented, which utilizes the concept of nonlinear feedback to speed up the operation. The analytical formulation for quantifying the effect of the feedback is put forward. The functionality of the proposed comparator is verified using simulations carried out on an Orcad Pspice tool using Taiwan Semiconductors Manufacturing Company (TSMC) 0.18 µm technology parameters. The resolution and delay are found to be ± 10 nA and 1.48 ns, respectively at a reference current of 1µA. The effects of parameter variations on the performance of the proposed comparator at different design corners is also studied. The usefulness of the proposed comparator is demonstrated through a 3-bit current mode flash Analog to Digital Converter (ADC) and its performance parameters are also calculated using simulations. The simulation results show that the 3-bit current mode flash Analog to Digital Converter exhibits no missing codes and has Differential Non-Linearity (DNL) of -0.25 Least Significant Bit (LSB) and Integral Non-Linearity (INL) of -0.19 LSB

Cellular modification of interrenal tissue induced by corticoid therapy and stress in three avian species

Corticotropic regulation of the interrenal tissue was explored in three avian species (quail, parakeet and myna) by application of dexamethasone therapy and stress. In response to corticoid administration, atrophy of all cortical layers from periphery to center was pronounced and no regional differences could be detected by histology and histometric analysis. Following exposure to acute formalin stress at the termination of chronic corticoid therapy, the interrenal tissue regularly responded by hypertrophy in all three types of birds. The absence of zonation in experimental atrophy in these species merits consideration in view of the zonal response observed in other avian species. The prompt response of the atrophic interrenal gland to stress indicates that the hypothalamo-hypophyseal regulation of the interrenal gland is qualitatively different from mammals