Digital data compression techniques for analogue blocks in mixed signal devices

Novel Built-In Self-Test (BIST) approaches for integrated optoelectronic systems are presented The methods are compatible with scan chain design and allow testing the internal functionality of the device, the interconnection between modules, the analog characteristics of the transmitters and receivers and the Bit Error Rate (BER) of the channels. The proposed approaches enable system evaluation under realistic operating conditions (including crosstalk degradation) through BER testing. They can speedup both circuit-level and system-level testing by providing means for accessing different parts of the circuit easily and allowing time-consuming performance tests to be run in parallel with boundary-scan tests. Some preliminary experimental results are presented to confirm the proposed approaches for analog and mixed-signal methods.

Built-in self-test (BIST) approaches are suitable for in-field testing since they do not require a tester for storage and application of test data. They also reduce the security vulnerabilities associated with loading and unloading of external test data into scan chains. As technologies evolve, in-field testing needs to address more complex defect and aging mechanisms that require specific deterministic tests. This can be addressed by BIST approaches that store test data on-chip and use the data for on-chip generation of both random and deterministic tests. In this case, there is a tradeoff between the amount of stored test data and the comprehensiveness of the test set that can be applied. This article explores this tradeoff in a specific context that has the following main features: 1) the initial stored test data is based on a stuck-at test set; 2) the target faults are single-cycle gate-exhaustive faults; and 3) the stored test data is enhanced gradually by test data based on a gate-exhaustive test set to increase the coverage of gate-exhaustive faults.

Electrical noise sensitive systems using mixed signal devices such as data converters and transceivers are prone to performance degradation due to switching regulator output ripple. Often switching regulator is used as power supply due to high efficiency performance it can offer. However, due to its undesirable output artefact, problems arise on powering these analog mixed signal devices directly from this regulator. Reducing the fundamental output ripple to a miniscule level is the main objective of this research. A novel concept using coupled magnetics or coupled inductors incorporated in a two-stage LC low pass filter was developed. This provides significant reduction on the fundamental frequency of switching regulator output ripple through the formation of a notch filter. However, to fully maximize the effect of the notch filter, the notch frequency should be tuned near the fundamental frequency location of the output ripple. The notch filter is created through resonance that provides better reduction of the fundamental output ripple in comparison to a conventional two-stage LC low pass filter with less volume and component count. A single package off the shelf coupled inductor can be used representing the inductors in the two-stage LC low pass filter. The resonance is formed by the mutual inductance created by the two coupled inductance and the series capacitor. Design imperfections such as the component tolerances, capacitance drift due to temperature and part-to-part coupling variations of the magnetic components are some factors that make the notch frequency hard to control. A phase-lock feedback circuit has been developed to overcome these design imperfections wherein it provides the loop correction and tuning control. A variable capacitor is used as a tuning element to align the resonant frequency with the switching frequency of the switching power supply therefore maximizing the notch filter effect to the fundamental frequency of the output ripple. Barium Strontium Titanate (BST) dielectric capacitor and off the shelf ceramic capacitor are the variable capacitors that can be used to make resonant tuning achievable. The coupled magnetics in a two stage LC low pass filter in combination with the automatic resonant tuning concept was filed as a patent last November 6, 2017 and was issued last June 11, 2019 entitled “LC filters including coupled inductors for reducing ripple in switching power supplies” with patent no. US 10,320,280 B2. The author of this thesis is the co-inventor of the issued patent with Analog Devices Global Unlimited Co. as patent assignee.

Data compression techniques in IoT-enabled wireless body sensor networks: A systematic literature review and research trends for QoS improvement

Summary Recent studies highlight the significant role of drilling fluid elasticity in particle suspension and hole cleaning during drilling operations. Traditional methods to quantify fluid elasticity require the use of advanced rheometers, which are not suitable for field applications. The main objectives of this study were to investigate the factors influencing drilling fluid viscoelasticity in the field and develop generalized models for determining the viscoelasticity of a drilling fluid using standard field testing equipment. Ninety-three fluid formulations used in this study included field samples of oil-based drilling fluids as well as laboratory samples of water-based, invert emulsion and other oil-based fluids. Basic rheological characterizations of these fluids were done by using a funnel viscometer and a rotational viscometer. Elastic properties of the drilling fluids (quantified in terms of the energy required to cause an irreversible deformation in the fluid’s structure) were obtained from oscillatory tests conducted by using a research-grade rheometer with double gap concentric cylinder geometry. Using an empirical approach, two noniterative models for quantifying drilling fluid elasticity were developed (one for unweighted and the other for weighted drilling fluids) by correlating test results from a funnel viscometer and a rotational viscometer to energy required to cause an irreversible deformation of the fluid’s elastic structure. The generalized models for the unweighted and weighted viscoelastic drilling fluids were able to predict the elasticity of drilling fluids with a mean absolute error of 4.67 and 5.28%, respectively. In addition, the models offer practical versatility by requiring only standard drilling fluid testing equipment to predict viscoelasticity. Experimental results showed that nonaqueous fluid viscoelasticity is inversely proportional to the oil-water ratio (OWR), and the presence of clay greatly debilitates the elasticity of the drilling fluids while enhancing their viscosity. In this paper, we present models for estimating unweighted and weighted drilling fluid elasticity using standard drilling fluid field testing equipment. Furthermore, we proposed a prudent approach for quantifying the viscoelastic property of a drilling fluid by measuring the amount of energy required to irreversibly deform a unit volume of viscoelastic fluid. The new models, combined with the recommended use of the energy dissipation (ED) concept, provide practical tools that can be used for developing optimum drilling fluid formulations and hydraulic programs for effective hole cleaning operations, improved equivalent circulating density (ECD) management, and mitigating barite sag problems.

New developments in tape backup include the use of Digital Audio Tape (DAT) and data compression techniques but, before we take a look at these new features — and some of the available tape units that make use of them — a discussion of tape backup itself seems appropriate. Readers who are thoroughly familiar with tape backup can skip directly to the paragraph headed ‘Data compression for low cost units’.

Integrated Circuit (IC) manufacturing processes have been successful in introducing complex high speed analog and mixed signal devices. The paper presents a novel method of testing analog ICs using periodic input stimuli and wide band undersampling. In its simplest form, the testing procedure can be implemented in a design by adding two simple components on-chip: an analog switch to sample the response signal at a particular node under test, and a buffer to bring the sampled values off-chip. Using a sequential undersampling algorithm to control the switch allows high frequency signals to be mixed down in frequency and driven off-chip using a low bandwidth buffer.

Virtual prototyping of pressure driven microfluidic systems with SystemC-AMS extensions

This paper presented a failure analysis methodology to overcome the difficulties of fault location encountered by pin leakage and some testing parameter failures in a mixed signal device. These types of failure generally cannot be solved by traditional electrical failure analysis methods.

We present an application of Defect Oriented Testing (DOT) to an industrial mixed signal device to reduce test time and maintain quality. The device is an automotive IC product with stringent quality requirements and a mature test program that is already in volume production. A complete flow is presented including defect extraction, defect simulation, and test selection. A major challenge of DOT for mixed signal devices is the simulation time. We address this challenge with a new fault simulation algorithm that provides significant speedup of over 100x in the DOT process. Moreover, a number of methods are presented to improve the accuracy of this algorithm. Based on the fault simulations, we determine a minimal set of tests which detects all defects. The proposed minimal test set is compared with the actual test results of more than a million ICs. We prove that the analyzed production tests of the device can be reduced by at least 50%.

This chapter focuses on the design and implementation of grounding on printed circuit boards (PCBs), particularly as it pertains to the three aspects of signal integrity, power integrity, and electromagnetic compatibility (EMC). It discusses the design and implementation of signal- and power-return paths (grounding) on PCBs and their interactions, and the role of planes in accomplishing the EMC and signal integrity design goals. The chapter also addresses the question of grounding design in mixed signal circuits and of data converters (analog-to-digital converters and digital-to-analog converters). It discusses the nature of the currents flowing in these devices, the vulnerabilities of precision data converters to internal and external noise, and the effects of various grounding schemes on their performance. The chapter further develops and provides justification for a general grounding philosophy that should be suitable for most mixed signal devices in the vast majority of cases.

This paper introduces some practical BIST solutions as a basis for a future self-testable MEMS-based magnetic field sensor. It is demonstrated that slight modifications of the system architecture can be used to allow both on-chip generation of electro-thermal stimuli and preprocessing of the sensor response. The external response analysis and thus the test procedure are then strongly simplified and require only a standard digital automatic test equipment.

Views Icon Views Article contents Figures & tables Video Audio Supplementary Data Peer Review Share Icon Share Twitter Facebook Reddit LinkedIn Tools Icon Tools Reprints and Permissions Cite Icon Cite Search Site Citation William E. Glenn, Henry Helmken; Satellite distribution of digital compressed video audio and data. AIP Conf. Proc. 25 January 1995; 325 (1): 83–89. https://doi.org/10.1063/1.47256 Download citation file: Ris (Zotero) Reference Manager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentAIP Publishing PortfolioAIP Conference Proceedings Search Advanced Search |Citation Search

Differential input-ouput buffers are frequently utilized in high-speed communication systems. Often, a transmit buffer is connected to a 100-Ω differential receive buffer through a passive interconnect link with no means of verifying the true differential signal quality of the transmitter. Additionally, many electrical protocol specifications are defined assuming differential transmitter termination into 100 Ω with no common-mode reference. Commercially available, active probe test equipment can be cost prohibitive or have limited functionality due to unwanted parasitics inherent in the active devices. This paper describes a passive high-bandwidth 100-Ω differential termination device for characterizing high-speed differential buffers using standard test equipment.

An engine head cover gasket in automobile engines is constantly exposed to high temperature and pressure conditions. The life time of an engine head cover gasket is important due to the increasing demand for more reliable automobile parts. The main failure mechanism of rubber gaskets, which is the aging due to temperature, can be determined using standard test equipment. The highly accelerated life test (HALT) is generally used for predicting the life time of rubber materials for a long period. Polyacrylate (ACM) with chlorine cure sites has been generally used for engine head gaskets. In order to improve the life time of such gaskets, ACM with carboxyl cure sites has been developed recently. In this study, we applied a mathematical model to obtain the recovery function of a rubber gasket, and utilized the fortran program in order to obtain the optimized recovery function by using the successive zooming genetic algorithm (SZGA). Comparisons of the mean squared error (MSE) between the function data and the experimental data have been made. The life times of ACM with carboxyl cure sites rubber gaskets for different compression rates were obtained using the Arrhenius model. More accurate quantitative predictions considering the maximum compression rate would be realized.