Costin Miron

Multiobjective optimization method for analog circuits design based on fuzzy logic

The paper presents a new method for optimizing analog circuit design. The method performs a multiobjective optimization, the parameter modification taking into account the degrees of unfulfilment for all the requirements. For the optimization problem formulation, it uses fuzzy sets to define fuzzy objectives and for the optimization strategy, it uses a fuzzy system to compute new parameter values. The solution of the multiobjective optimization is a set of Pareto optimal points and we try to find it by means of a population of solutions. After introducing our optimization method, we validate our method by optimizing the design of a basic two stage CMOS op-amp. As expected, the results prove that the method is efficient and supplies very good final optimal solutions.

A fuzzy optimization method for CMOS operational amplifier design

The aim of the paper is to present a fuzzy method for the optimization of the CMOS operational amplifier design. Our method uses fuzzy systems or fuzzy sets in all stages involved in the optimization process. In order to reduce the time spent for circuit performance evaluation, we use fuzzy system to model each circuit performance. The optimization problem formulation is accomplished in a flexible manner using fuzzy sets to define fuzzy optimization objectives. We use qualitative design knowledge to modify the design parameters in each iteration. This is done using a fuzzy system for each parameter. After introducing our fuzzy optimization method we design a basic two-stage CMOS operational amplifier.

Adaptation platform for autonomic context-aware services

Most context-aware services are not autonomic because of two main reasons. The first one is that a context-aware service reacts only to context states that are entirely predicted by the developer. The second reason is that the adaptation control is based on predefined, application and context-specific policies. In this paper we propose a solution based on an application-context description, which allows the machine to autonomously discover the context structure and the adaptation strategies. We have tested our model using a simple scenario where a forum service is adapted to the user language.

A unitary analysis of voltage mode and current feedback op-amp circuits

This paper presents a unitary analysis method for voltage mode (VM) and transimpedance-current feedback (CFB) op-amp circuits. This methods uses a unified model for both op-amps; thus it permits a direct comparison for the circuit parameters. The point of the presented method is the separation of the signal graph of the analyzed circuit in two different paths: one that controls the gain and another that determines the circuit bandwidth. Thus one obtains a direct sight on the circuit elements that control this parameters. We extend the analysis method on differential current feedback (DCFB) op-amps circuits. Symbols for CFB and DCFB were introduced to simplify the circuit descriptions. As an application we analyze some high precision and large bandwidth amplifiers.

A method to design ternary multiplexers controlled by ternary signals based on SUS-LOC

In this paper, a method to design ternary multiplexers with any number of inputs is presented. The basic circuit used to design all ternary multiplexers is the 3-to-1 multiplexer. Starting from the basic multiplexer in binary, we design and simulate the 3-to-1 multiplexer. The multiplexer is built with the basic ternary functions such minimum and maximum. The control circuit of the 3-to-1 multiplexer is design with ternary circuits too, called indicators of logical level. Using one or more 3-to-1 ternary multiplexers, the ternary multiplexers with any number of inputs can be designed. All multiplexers are realized using Supplementary Symmetrical LOgic Circuit Structure (SUS-LOC). The operation of the multiplexers was proved by simulation in the Orcad environment.

Master-Slave ternary D flip-flap-flops with triggered edges control

The paper is dedicated to Master-Slave ternary D flip-flap-flops with triggered edges control. First, the flip-flap-flops with binary clock are implemented. Next, the C0, C1 and C2 ternary gates are used to improve the control of triggered edges for flip-flap-flops with ternary clock. The 3-trits shift register realized with both types of flip-flap-flops (with binary and ternary clocks) is also presented. The correct operation of the flip-flap-flops was demonstrated by simulations in the Simulink environment.

Software minimization of ternary functions using Matlab

In this paper a minimization algorithm for ternary function based on the Hurst method is presented. The algorithm minimizes ternary functions with two, three and four input variables and was implemented using the Matlab environment. Both, the partial results and final expressions are provided. The final expressions are obtained by combining two different partial results and are with respect to the truth table for the ternary input function. The friendly and intuitive interface makes the implemented algorithm easy to use, without requiring any background in the field of ternary minimization.

A Top-down Approach to Gaining an Insight into a Transistor Circuit in CS Connection

This paper explains why and how the very same circuit (a transistor circuit in CS connection) is able to perform multiple applications depending on the use of the transistor in different operating regions. Families of transfer characteristics of the circuit are used to deduce the possible applications. In this way, the emphasis is transferred to understanding the intrinsic operation of a circuit, which opens the perspective for multiple applications, as opposed to the traditional approach, where the emphasis is placed on circuit applications.

‘On Optimising the Feedback Components in a Voltage-Feedback Amplifier’: A Simpler Derivation of the Final Expression

The open-loop gain of a typical two-stage transistor voltage-feedback amplifier is put in the form of a ratio between its value in the absence of feedback components and the product of two gain-degrading factors. Minimising this product results in maximising the open-loop gain, and the corresponding algebra is much less laborious than the one in the paper referred to in the title.1