Digitally programmable second generation current conveyor‐based FPAA

The work concerns the problem of switching processes in VLSI technology, reprogrammable analog arrays technology, and nanotechnology. Informatics is a discipline of science exploring the laws of processes of coding, processing, storing and transferring information or data. The movement and processing of Information is indissolubly connected with the switching of states of Structures carrying the data. In general, the changes of structure state can be forced through the changes of carried data parameters with unchanged structure configuration, through the switching of structure configuration or switching of the structure conformation. Switching is exhibited in different technologies by different basic elements (basic Structures or building blocks) and specified operations performed on them in order to obtain the object or product with desirable properties including also the dynamic changes of those properties. Dealing in turn with so different cases as VLSI Structures, FPAA (Field Programmable Analog Array) Structures and nanostructures, it is possible to notice, that the common feature takes a stand in solving the tasks related with them, rely on choice of certain basic elements critical for structure behavior as e.g. multicon-ductor transmission lines (MTL), configurations of FPAA substructures or whole FPAA systems, molecule conformations, and it is operated on them analyzing the internal switching processes. The design of interconnects in a high-speed integrated circuits and systems requires analysis and computer simulation based on interconnects models in the form of coupled, multiconductor transmission lines. The fundamental parameters for matrix description (or modeling, simulation and design) of MTL include the capacitance matrices. Precisely, these are the matrices per-unit of length, the capacitance coefficients matrix called Maxwell matrix of MTL and the two-terminal capacitance matrix. If the two-terminal matrix is known, the Maxwell matrix used for MTL switching characteristics estimation, can be computed from the two-terminal matrix. In the work, two methods of determination of the Maxwell matrix from measurements are presented: passive, indirect measurements and measurements with active separation. The measurements were performed basing on fabricated VLSI test structures named ST2 and AF4. The measurement results arę complemented with the accuracy analysis. Scaling of structures is conformed to fast switching, high-speed integrated YLSI/ULSI integrated circuits design. In case when the geometrical dimensions decrease, multiconductor interconnections between parts of a system become strongly coupled MTL, which in switching moments have to be recharged with smali geometry devices. In the work the method and numerical computations of scaled (in geometrical sense) MTL for its energetical characterization is presented. This can be used for proper design of MTL geometrical parameters in a YLSI/ULSI structures working with a high-speed switching. The results of measurements of the switching delay in the scaled in dimensions VLSI gates, are also included. Poor matching of the switched MTL reveals with reflections extending the time of switching and can be source of switching noises. The method of so called diagonal matching is presented in the work. The time of switching in the high-speed planar VLSI structures (driver and receiver gates connected via the long microstrip line) depends on dielectric properties of substrate under the signal and ground microstrip lines. Most important for fast switching is recharging of dielectric in the presence of the dielectric absorption phenomenon. In the work, the model of dielectric absorption and its identification algorithm based on the experimental data is presented. This model can be used for simulation of switching transients in the interconnections of different length for given technology, taking into account the dielectric absorption. Nowadays, it is apparent that many designs are evolving towards mixed-signal systems. In these kind of circuits in CMOS technology, the analog part of a system and an interface are composed frequently basing on switched capacitor (SC) technology and in the newest solution basing on field programmable analog arrays. There are two main weak points in fast switching of reconfigurable FPAA: firstly, the time of download of the configuration from supporting program or EEPROM memory with the time of transients in a FPAA chip when the download is finished and the chip undertakes its function, and secondly, for recently accessible FPAAs, there is no possibility of switching its parameters values and a part of active structure on-the-fly (during FPAA operation). In the work, the solution of fast switching of the part of working FPAA for adaptive operation is presented. The solution is based on external control of one or few CAB (Configur-able Analog Błock) in the working FPAA. The solution of the download time problem in FPAA chip operating in continuous time fashion is based on parallelization of the FPAAs and "hiding" of the download time and time of transients after download. Finally, the applications of the modified, fast switched FPAAs systems for adaptive and predictive control with possible application in the microreactors control have been presented. In the nanonetworks, an information is transferred through the state of moving molecules. In a short-distance communication (inside the closed area determined by the borders of nano-process) the state of the signaling molecules is forced through the binding via hydrogen or covalent bonds of another molecul or through the interaction of the environment's parameters.These processes in biological nanonetworks are performed in the signal transduction cascades and the same procedures are applied in the nanotechnical system of informatics. We considred these process with emphasis on the fusion of cascades. In general, these interactions lead to the switching of conformations of the molecule. In the work, we focused on biocompatible nanostructure introducing the standard, formal description of molecular structures , methodology of modeling and simulation of the conformation changes, and hierarchical description of nanonetworks useful in the switching conformation studies. The simulation methodologies based on the dynamic programming, Monte Carlo and Nascent Protein Folding algorithms are investigated. Moreover, nanotechnological, two-stage production processes based on the "gluey matrix" concept are discussed.

A field programmable analogue array (FPAA) for biomedical applications is introduced in this paper. The proposed FPAA is based on operational transconductance amplifier (OTA). The FPAA consists of configurable analogue blocks (CABs) arranged in three sections. Each section implements an OTA-C filter of reconfigurable order with variable gain, and bandwidth. Direct connections between CABs within a section, and between sections are present. The proposed reconfigurable FPAA permits different connections between its sections, providing a wide range of possible applications. Allowing the implementation of full biomedical systems, such as the analogue front-end (AFE) for biopotential signal acquisition. Reconfigurability and functionality of the proposed FPAA architecture is demonstrated through mapping of low power filters and AFE on FPAA. Simulations results for a 90 nm CMOS technology are given. The simulation results of filter and AFE on FPAA are compared to off- FPAA simulations.

In this paper, the prototyping of 3rd order, 4th order, 5th order, and 6th order sigma-delta analog to digital converters (Σ∆ ADCs) has been presented. It summarily portrays the method implemented for configuration and reconfiguration of the proposed circuits by using Field Programmable Analog Array (FPAA). Their function was determined in the time domain at a constant 1 V supply voltages which is a sinewave input signal of 20 kHz frequency. The sampling frequency is fs = 4 MHz and the Oversampling ratio is OSR = 50 which yields a bandwidth of 40 kHz. Practical experimentation of the circuits was carried out using the AN221E04 FPAA device from Anadigm. Circuit realization of 3rd order, 4th order, 5th order, and 6th order sigma-delta analog to digital converters (Σ∆ ADCs) using FPAA are shown in figures. Also, sinusoidal input and output waveforms of implemented architectures are shown. A comparison of the proposed designed circuits with the various sigma-delta modulators published in the previous paper is also shown. The proposed sigma-delta modulators can be applied in the investigation and practical study of designing programmable analog devices and systems based on FPAA.

This paper presents the results obtained in the simulation and implementation of adaptive and matched filters using the new technology of FPAA (Field Programmable Analog Arrays). The proposed filter structures are intended to be used in conditioning of signals from radiation sensors but can be also used in any application that necessitates signal extraction from noise. For the implementation of the filter were used configurable analog blocks (CABs) from Anadigm AN221E04 dynamically reconfigurable chip. The most important advantage of the proposed design is represented by the possibility to reconfigure the filter characteristics in order to meet application specific requirements.

Although chaotic signals are considered to have great potential applications in radar and communication engineering, their broadband spectrum makes it difficult to design an applicable amplifier or an attenuator for amplitude conditioning. Moreover, the transformation between a unipolar signal and a bipolar signal is often required. In this paper, a more intelligent hardware implementation based on field programmable analog array (FPAA) is constructed for chaotic systems with complete amplitude control. Firstly, two chaotic systems with complete amplitude control are introduced, one of which has the property of offset boosting with total amplitude control, while the other has offset boosting and a parameter for partial control. Both cases can achieve complete amplitude control including amplitude rescaling and offset boosting. Secondly, linear synchronization is established based on the special structure of chaotic system. Finally, experimental circuits are constructed on an FPAA where the predicted amplitude control is realized through only two independent configurable analog module (CAM) gain values.

The use of the oscillation test strategy to test configurable analog blocks of field programmable analog arrays (FPAAs) has been proposed previously, solving the complex problem of test stimuli generation. An improvement to that technique is presented in this paper, using the resources of the FPAA to build an output response analyzer. This new approach offers a full built-in self-test scheme with no area overhead and requiring a low cost automatic test equipment. Experiments show the efficiency of the approach in detecting parametric faults of the tested components.

The design details and test results of a field-programmable analog array (FPAA) prototype chip in 1.2- mu m CMOS are presented. The analog array is based on subthreshold circuit techniques and consists of a collection of a homogeneous configurable analog blocks (CABs) and an interconnection network. Interconnections between CABs and the analog functions to be implemented in each block are defined by a set of configuration bits loaded serially into an onboard shift register by the user. Macromodels are developed for the analog functions in order to simulate various neural network applications on the field-programmable analog array.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>

A new wideband BiCMOS current conveyor is presented. It has an advantage of low input resistance at port X. It is therefore used to design high frequency applications such as the high frequency programmable filter presented in this paper. PSPICE simulations promise good performance. The voltage supply is /spl plusmn/2.5 V.

This paper presents a new programmable universal filter and quadrature oscillator based on single output operational transconductance amplifiers (OTAs). The proposed universal filter and quadrature oscillator can be achieved into single topology by programming using analog switches. When the circuit programs as a universal filter, it can realize low-pass, high-pass, band-pass, band-stop and all-pass filters with orthogonal and electronic controls of the natural frequency and the quality factor. When the circuit programs as a quadrature oscillator, it provides three-phase quadrature output signals which the condition of oscillation and the frequency of oscillation can be controlled orthogonally and electronically. The proposed structure can be realized based on single output OTAs which is easily implemented both commercially available integrated circuits as OTAs and complementary metal-oxide semiconductor and bipolar junction transistor OTA as IC forms. The performance of the proposed circuit is investigated by SPICE simulation using standard 0.18 μm CMOS process and experiment test using LM13600 discrete component integrated circuit as OTAs is used to confirm the workability of the new circuit.

This paper aims to represent a proposition of an innovative and novel methodology applicable in detecting and classifying the power quality disturbances present in the supply to the induction motor. In all practicality, considering circumstantial real world applications, induction motors are usually operated on load. If the supply voltage is varied in any way, it would adversely affect the normal operation of the motor. In the present work, a healthy induction motor is subjected to power quality disturbances like balanced voltage sag, balanced voltage swell, unbalanced voltage sag and unbalanced voltage swell. For the purpose of detecting these power quality disturbances, discrete wavelet transform is applied to the stator current of the induction motor. The stator current wavelet coefficients are fed as input to the neural network for the classification purpose. Radial basis neural network and feed forward neural network have been independently trained and tested. The observation about the feedforward network having higher performance efficiency as compared to the radial basis network, has been seen.

In real world applications, induction motors are normally operated on load. Any variation in the supply voltage, would adversely affect its normal operation. Hence it is important to detect any power quality disturbance and identify the nature of the disturbance. A major issue is to find the motor parameter which can satisfactorily identify and classify the disturbance. This paper proposes a novel method for the detection and classification of PQ disturbances in the supply to induction motor using the signature of the stator current. The tools used for the analysis are wavelet transforms and neural network. In the first stage the stator current is sampled and DWT is applied to it to capture the feature of the disturbance. The DWT co-efficients so obtained are used as input to a feed forward neural network, in the second stage, to classify the disturbance. This method has been tested for different PQ disturbances such as balanced voltage sag, balanced voltage swell, unbalanced voltage sag and unbalanced voltage swell (or simply called as unbalance in the magnitude of the supply). The method has been found to be effective for varying degrees of disturbance. It is observed that the proposed network has performance efficiency greater than 97%.

In this paper, an approach for reducing the torque ripple in a two phase unsymmetrical induction motor is analyzed. A single phase induction motor is basically a two phase induction motor and generally, the windings on the stator are not identical. Hence, it is called unsymmetrical two phase induction motor. If an unsymmetrical motor is supplied by two phase balanced supply voltages then the ripples in the electromagnetic torque are unavoidable. However, if the supply voltages are made unbalance to counter the unbalance in the windings the torque ripple can be reduced. The mathematical model of the machine in stator attached reference frame is used to derive the torque expression in terms of stator currents. The torque expression consists of a constant term and a pulsating term. These terms used together unable finding the conditions on stator currents and hence stator voltages so that the ripples in the torque produced can be mitigated.

Design and simulation of a digitally controlled CMOS fully differential current conveyor (DCFDCC) is presented. A novel current division network (CDN) is used to provide the digital control of the current gain between terminals X and Z of this DCFDCC. The proposed DCFDCC operates under low supply voltage of /spl plusmn/1.5 V. The realization of the DCFDCC using the new CDN is presented by two approaches. First approach has linearly proportional current gain with the digitally controlled parameter of the CDN, while the second approach exhibits current gain between terminals X and Z greater than, or equal to, one. Applications of the DCFDCC in realizing second order universal active filter and variable gain amplifier are given. PSPICE simulation confirms the performance of the proposed blocks and its applications.

Bi-stable displays form the foundation of a novel and attractive LCD technology. From now on, images can be maintained on the LCD after driving voltages have been withdrawn from the electrodes. In low frame-rate applications such as e-books, e-labels, smartcards etc., this offers a major improvement in power consumption and battery life. However, bi-stable displays require high driving voltages and complex waveforms. Furthermore, the nature of some applications doesn't allow the use of relatively large passive components. This rules out more traditional approaches for high-voltage generation with external coils or capacitors. This paper describes the design of completely integrated and programmable high-voltage generators capable of generating output voltages up to 50V out of a 3 V supply voltage. Features like 8-bit output voltage programmability and stabilisation were implemented to make this type of high-voltage generator suitable for bi-stable display drivers. Design aspects and simulation results are discussed, as well as measurements on prototype generators implemented in the 0.7μm 100 V I 2 T100 technology from AMI Semiconductor.

In the literature, a modified Nauta's OTA has been proposed for achieving higher PSRR and CMRR. In this paper, a modified Nauta's OTA with double CMOS pair is proposed and is used for implementing a programmable Gm-C filter. The double CMOS pair enables the transconductance to be varied by varying the bias voltages at high impedance nodes. This in turn results in programmability of the filter (F-tuning). For the purpose of comparison, the proposed OTA and Nauta's OTA reported in the literature are implemented in UMC-0.18μm CMOS process and studied through simulation. The proposed OTA results in 11 dB increase in the PSRR and 21 dB increase in the CMRR compared to the Nauta's OTA. The tunable second order Gm-C band pass filter using the proposed OTA is implemented and studied. Simulation of filter is done with BSIM3V3 parameters under (±0.9V) supply voltage and (±1.4V) supply voltage for biasing of double CMOS pair. It is verified from the post-layout simulation that the filter can be tuned over the range (10MHz-300MHz).