Boonchareon Sirinaovakul

A novel balanced differential-pair multi-output CMOS CCCII

A novel structure, based on balanced differential-pair, is proposed to implement the single/multiple output CMOS second-generation current-controlled conveyors (CCCII). A balanced-output CCCII is demonstrated and its performances are simulated based on the AMSs 0.35 mu CMOS process by the HSPICE simulations. The large-signal simulations present the compatibility of the proposed structure and the theorem of CCCII. The bandwidth of transresistance up to over 600 MHz is noticed via small-signal simulations, which cause the device earns its place as one of the attractive RF analog building blocks especially to current-mode circuits. A current-mode filter based on Tow-Thomas (TT) structure is synthesized to verify the working capability and the usefulness of current-controlled transresistance.

A balanced differential-pair CMOS CCCII with negative intrinsic resistance

A novel structure, based on balanced differential-pair, is proposed to implement the CMOS CCCII with negative intrinsic resistance at port X. HSPICE simulations, based on the AMSs 0.35µ CMOS process, are conducted, which certainly confirm the occurrence of negative resistance. To demonstrate its capability, a two-phase current-mode oscillator is synthesized based on two lossless integrators. As little error in oscillated frequency is observed, the proposed structure earns its place as one of the attractive negative-resistance simulators.

Effects Of OTA's Nonidealities On Bandpass Otabased Tow-thomas Biquad And Compensation Via Simulated Annealing Algorithm

In this work, the practical response of a very compact version of OTA-based TT biquad which is not suitable to compensate with regular methods, is compensated by the use of SA algorithm. For effective compensation, the OTA nonidealities are precisely defined based on the commercially available OTA, LM13700 from National Semiconductor. The initial solution is obtained via the ordinary method of an analogue filter design based on the utilization of ideal-OTA-based transfer function which provides the response that is much deviated from the desired bandpass response especially in the pole frequency closing to the OTAs finite bandwidth. The Matlab is used as the tool for implementing the compensation process, while the results which are the circuit parameters are being verified by the OrCAD PSPICE simulation. Using the SSE based cost function; the simulation displays the significant improvement of the compensated response compared to the initial solution but still not acceptable. To retrieve the remarkable response, the weighted SSE is utilized while maintaining others parameters

The Complete Passive Equivalent Circuit Of The Practical OTA-based Floating Inductor

In this research, we have studied the practical OTA-based floating inductor and propose its complete passive equivalent circuit where the finite bandwidth effect which used to be neglected in the previous work is now included. Furthermore, we also propose the accuracy evaluation of this passive equivalent circuit by comparing it with the target active OTA-based floating inductor. Finally, we mention our further studies which are the inclusion of the mismatch among each OTA and the modelling of the passive equivalent circuit of the other type of the OTA-based floating inductor

Novel Bandpass-Biquad Evaluation Model for Computer-Based Compensation of an OTA-C Filter

The novel mathematical bandpass-biquad evaluation model based on poles/zeroes location for computer-based compensation of an OTA-C filter is proposed. In proving of models validation, the SA algorithm is utilized for searching a compensated circuits parameters of the most compact version of bandpass OTA-based TT biquad, which is not suitable for classical compensation methods of OTAs nonidealities. A CMOS OTA with non-linear transconductance and low output resistance is chosen as the based OTA for the tested circuit. Through experiments, the proposed pole-zero-based model is proved very suitable for computer-based evaluation of bandpass biquad in compensation process. The comparing experiment is also conducted to measure the performances of the proposed and the existed model. The results provide a conclusion that the proposed model is superior in the requirement of computing power, and the evaluation ability for compensation process.

A Compensation of Continuous-Time OTA-Based Bandpass Filter Employing Genetic Algorithm

The method for utilizing the GA to compensate the OTA-based bandpass filter is presented. The example structure is one of the most compact OTA-based biquad which is not suitable with the ordinary active/passive compensation methods. The compensation process results in admirable solutions within an incredibly short time. The 26 one-half fractional factorial experiment is conducted to observe the GA and biquad parameters that might significantly affected the level of compensation. Based on the experiment, the maximum number of generations, the population size, and the tournament size are roughly recommended

A heuristic compensation of OTA-C bandpass biquad based on CMOS OTA

The process of computer-based compensation of an OTA-C bandpass biquad by means of heuristic search is proposed. The SA algorithm, which is very simple and can be easily deployed by analogue designers, is selected for demonstration along with the very compact version of OTA-C TT biquad, which is not suitable to compensate with regular methods. A wideband but low and non-linear transconductance CMOS OTA is selected to be the fundamental OTA. The initial solution is obtained via the ordinary method of an analogue filter design based on the utilization of ideal-OTA-based transfer function, which provides the response that is much deviated from the desired bandpass response. Two cost functions are examined and compared based on the computing-time and quality of compensation. The MATLAB is used as the tool for implementing the compensation process, while the HSPICE simulation is verifying the results, which are the circuit parameters. The demonstration displays evidences of effective compensation via the significant improvement of the final solution compared to the initial solution.

Intelligent tutoring and knowledge base creation for the subject of computer programming

This paper presents a designed architecture of a practical dialogue-based tutoring system for the subject of computer programming and the knowledge base creation for the intelligent tutoring system. The tutoring system focuses on helping learners learn by solving programming exercises and it is dialogue-based since it processes the inputs which are natural language questions from learners and generate natural language explanation as response to questions from learners and explanation of solutions. In generating the explanation, the tutoring techniques as well as natural language techniques are incorporated to make the generated text cohesive and aggregated. All of these methods employed are to create the intelligent system which is practical and allows for collaborative learning.

Novel Conventional Standard Linear Element Based Complete Passive Equivalent Circuit Models of the Practical OTA-Based Inductors

In this research, the practical OTA-based inductors of all structures have been studied and their complete passive equivalent circuit models, where the effects of both parasitic elements and finite opened-loop bandwidth have been taken into account, also contain only the conventional standard linear elements i.e. the ordinary resistor, inductor and capacitor, without any infeasible high order element e.g. super inductor etc., have been proposed. The resulting models have been found to be excellently accurate, excellently straight forward, far superior to the previously proposed ones and completely realizable by the passive elements. Hence, the proposed passive equivalent circuit models have been found to be the convenience and versatile tools for the implementation of any analog and mixed signal processing circuits and systems.