Showing papers on "Decoupling (electronics) published in 1990"

Internally decoupled integrated circuit package

Abstract: A decoupling scheme is presented which is well suited for use with any type of integrated circuit package. In accordance with the present invention, a flat decoupling capacitor is attached directly to the top of an IC die and is electrically connected to the IC by means of raised conductive bumps provided either on the surface of the decoupling capacitor or on the IC die surface. These conductive bumps interconnect the internal electrodes of the capacitor to the power and ground circuits of the IC. The resulting decoupling scheme provides a decoupling loop with an inductance which is significantly lower than previously disclosed decoupling loops.

Molded integrated circuit package incorporating thin decoupling capacitor

Abstract: A decoupling scheme which is particularly well suited for use with molded integrated circuit packages incorporating lead frames is presented. In accordance with the present invention, a thin decoupling capacitor is used which is comprised of a ceramic or like substrate having printed or otherwise applied thereon conductive layers, dielectric layers (e.g., glass/ceramic dielectric paste or dielectric sol-gel) and protective layers. Mounted on this thin capacitor is an integrated circuit chip. This thin capacitor/IC chip assembly is attached directly to the IC lead frame and thereafter encapsulated within the molded package resulting in a decoupling scheme which is internal to the molded IC package. Printed conductors on the thin capacitor's ceramic substrate are attached to appropriate fingers of the lead frame by welding, soldering or the like to effect strong mechanical and electrical contact.

Adaptive decoupling control of induction motor drives

Abstract: A novel control approach for a robust induction motor drive system with a voltage source inverter has been developed. In the scheme, the induction motor and its corresponding inverter gating signal are controlled using the decoupling control theory. In addition, an adaptive optimal speed regulator employing the model reference adaptive control (MRAC) is incorporated into the drive system to compensate for unfavorable errors. The principles and special features of the control scheme are discussed, and the configuration of the drive system is presented. Comparison is made between conventional proportional plus integral (PI) control and the MRAC. Test results show the robustness and superior dynamic performance of the proposed control system. >

Stably suspended organic peroxy bleach in a structured aqueous liquid

Abstract: An aqueous based structured heavy duty liquid detergent formulation is disclosed, which contains selected bleaches, surfactant combinations, borate polyol pH jump systems, and selected decoupling polymers.

Packaged integrated circuit with in-cavity decoupling capacitors

Abstract: An integrated circuit package is disclosed which has decoupling capacitors mounted within the cavity. A first embodiment has a thin-film capacitor mounted to the die attach of the header, with a first wire bond connecting the top surface to a lead finger of the header, and with a second wire bond connecting the top surface to the semiconductor chip mounted in the package. A second embodiment allows for decoupling of the power supply to a reference voltage other than that of the substrate, by providing a stacked capacitor where the top capacitor has a smaller cross-sectional area than the lower capacitor. Bond wires connect the top surface of the top capacitor to a first power supply lead, such as V cc , and to the V cc bond pad of the chip. The top surface of the lower capacitor, and consequently the lower surface of the top capacitor, are connected by bond wires to the reference supply (V ss ) lead of the package and bond pad of the chip.

Integrated circuit package having an internal cavity for incorporating decoupling capacitor

Abstract: A decoupling scheme is presented which is particularly well suited for use with integrated circuit packages having internal cavities for receiving an integrated circuit chip such as Pin Grid Array (PGA) packages, ceramic dual-in-line packages, ceramic flat packs and ceramic leadless chip carriers. In accordance with the present invention, a decoupling capacitor (which preferably comprises a very thin high capacitance layer made by a thick film or thin film process sandwiched between an inner and outer electrode layer) is positioned within the internal cavity of an integrated circuit package such as a PGA package and electrically connected to the IC chip within the cavity. In a particularly preferred embodiment, the decoupling capacitor has a novel configuration for improved heat transfer. This novel configuration includes a pair of parallel plate electrodes wherein the upper electrode has extended flaps which wrap around the top surface of the decoupling capacitor.

Magnetically releasable target lock

Abstract: A magnetically releasable pin lock which comprises catch elements mounted to pivot about axes perpendicular to and displaced from the pin axis and elongated magnetizable actuation elements which extend from the catch elements along the pin axis to be acted upon by applied magnetic decoupling fields and to move in response to such fields to pivot the catch elements and release the pin.

Robust design of cascade control

Abstract: A design concept for cascade control that ensures enhanced robustness by minimizing the mutual influence among the cascaded loops is proposed. This is achieved by complete decoupling of the design and performance of two (or more) cascaded control loops. The decoupling applies not only to static aspects (windup and saturations) but also to possible degradation of dynamic performance. The practical impact of the design is illustrated by both analytic and numerical examples. >

Shared BiCMOS sense amplifier

Abstract: A switching circuit for SRAM memory cells is disclosed. The circuit electronically decouples input lines to sense amplifiers from unselected arrays of memory cells. The decoupling results in a large decrease in the amount of parasitic capacitance that the selected inputs would encounter.

Direct adaptive decoupling control for general stochastic multivariable systems

Abstract: This paper presents a novel adaptive decoupling controller for general stochastic multivariable systems with arbitrary time delay structure. The decoupling controller is constructed using a diagonal dynamic precompensator to diagonalize the system interactor matrix and then combining the feedforward control strategy and the generalized minimum variance approach. It cannot only control unstable and'or non-minimum phase processes but also decouple the closed-loop systems both dynamically and in the static state. It is adaptively implemented in direct form. The global convergence properties and parameter estimate consistency for this adaptive decoupling algorithm are also discussed. It is shown that this adaptive controller not only has globally convergent properties but also generates strongly consistent parameter estimates. The results of simulations and an application are proposed to demonstrate the effectiveness of the algorithm.

Development and optimization of multipulse propagators: Applications to homonuclear spin decoupling in solids

Abstract: We introduce a new class of semi‐windowless pulse sequences for homonuclear decoupling in solids. The development and optimization of the multiple‐pulse sequences relies on the definition of quality factors that reflect the proximity of the created effective Hamiltonian to the desired Hamiltonian. A quality factor based on the average Hamiltonian theory gives a global view of the existing solutions. However, the sequences were optimized using a quality factor based on exact numerical solutions of the Liouville von Neumann equation. The new decoupling sequences are stable over a wide range of coupling constants and chemical shifts.

Flux and torque decoupling control for field-weakened operation of field-oriented induction machines

Abstract: One of the primary advantages of field-oriented induction machines for high-performance applications is the capability for easy field weakening and thus full utilization of the voltage and current ratings of the invertor to obtain a wide dynamic speed range. This attribute has not been widely developed, however, because of the difficulty in actually knowing the flux magnitude and the effective rotor time constant at each operating point as needed for indirect field-oriented controllers. A straightforward approach is presented for estimating and fully decoupling the rotor flux and rotor time constant terms in indirect field-oriented controllers. This approach is based on a combination of both the intrinsic magnetic linearity of the field-weakened machine and the fully decoupled stator current and voltage equations which result from the use of delta-modulator current regulators. >

Control structures for disturbance rejection and decoupling of distillation

Abstract: The process gains for different distillation control structures can be calculated through transformations from known gains of one arbitrary structure. In this paper the transformation is utilized for calculation of a two-point distillation control structure which, in the steady state, simultaneously rejects disturbances in the feed composition and in the feed flow rate and results in implicit decoupling between the two product control loops. This disturbance rejecting and decoupling (DRD) structure is tested on a model of a 15-plate pilot-plant distillation column. It compares favorably with standard structures for dual composition control. Experimental results agree with the simulation results.

Input-Output Decoupling with Stability for Hamiltonian Systems

Abstract: The input-output decoupling problem with stability for Hamiltonian systems is treated using decoupling feedbacks, all of which make the system maximally unobservable. Using the fact that the dynamics of the maximal unobservable subsystem are again Hamiltonian, an easily checked condition for input-output decoupling with (critical) stability is deduced.

Advanced decoupling using ceramic MLC capacitors

Abstract: The author traces the evolution of early decoupling methods to present uses and some future directions. He tries to present a broad awareness that might reduce repetition and introduce a possible solution to the decoupling problem, noting that recent developments in high-speed decoupling have been in multiple simultaneous directions. The refinement of one design or technique has not necessarily led to the discovery of the next; rather, the developments in the different methods have usually been parallel, specific-application dictated. It is the multiple specific requirements that have led to the varied venues in design and technology. Attention is given to the development and utilization of the following devices: the four-terminal power entry capacitor, the power-plane decoupling capacitor, the 10- mu F 20-pH capacitor, and interdigitated leads. >

Effects of oxygen removal in superconducting ErBa2Cu3Ox

Abstract: Neutron diffraction, magnetization and υSR experiments were carried out with the aim to study the effects of oxygen removal in superconducting ErBa2Cu3Ox. Two main effects increase when approaching the oxygen concentration x=6.4 where superconductivity is suppressed: (i) the electron transfer from the Cu(1)-O chains to the Cu(2)-O planes and (ii) the decoupling of these superconducting planes.

Very large scale integrated circuit package, integrated circuit carrier and resultant interconnection board

Abstract: The package (10) of the integrated circuit (11) includes a TAB carrier (12), the supply conductors (15b) of which comprise shielding elements between groups of signal conductors and have a length that is largely shunted via a corresponding potential conductor plane (26b) of the decoupling device (24) of the package.

Photodecoupling of cross-links in polymeric gels

Abstract: Poly(butyl methacrylate) gels with photolabile cross-linked acyloxime units were prepared. The acyloxime moieties are scissioned on exposure to UV radiation, the cross-links decouple, and the solid material is thereby solubilized. The quantum yield of cross-link decoupling is about Φ=0.03. The physicochemical consequences of cross-link decoupling are investigated

Circuit arrangement for switching of rf signals

Abstract: A circuit arrangement for switching-through (transit switching) of RF-signals is provided. The signals from several RF-signal sources are switched via controlled diode paths (D1-D3, D6-D8) wherein capacitance diodes (D4, D5, D9, D10) are used for achieving a high value of decoupling between sources in the unenergized state.

Decoupling technique for transmit coils in NMR spectroscopy and imaging.

Abstract: A decoupling structure using an additional LC resonant configuration for NMR transmit coils is analysed and the probe sensitivity of the receive coil with the decoupled transmit coil is calculated using simple circuit models. An adjustment-free technique for the decoupling circuit under different loading conditions is proposed using the calculated results and demonstrated by experiments. The proposed method can simplify the probe operation.

Robust Nonlinear Control of Flexible Space Structures

Abstract: In this paper we describe results on the robust implementation of decoupling control for multibody systems with flexible interactions. Requirements for decoupling control arise in input-output linearization of certain principal system outputs with respect to available controls. In many applications it is desired to decouple multibody dynamic interactions from critical system outputs using available controls. For decoupling control implementation to be robust it should be insensitive to model perturbations Here we consider parasitic dynamics arising from flexible interactions and consider the role of reduced order modeling and the implementation of Partial (input-output) Linearizing Feedback control. We highlight the importance of model reduction based on time scaling of the decoupled or zero dynamics.

Control of induction motors via singular perturbation technique and nonlinear feedback control

Abstract: A description is given of a design for controlling induction motors with high dynamic performance by decoupling control over rotor speed and motor flux. The singular perturbation technique and nonlinear feedback control technique are utilized. Three different decoupling control schemes based on rotor flux, stator flux and air-gap flux are developed. The proposed controllers consist of three subcontrollers: a saturation current controller, a nonlinear feedback controller, and a flux simulator. Simulation and experimental results are presented to verify that these control schemes provide decoupling control of rotor speed and motor flux with excellent dynamic behavior. A microprocessor-based drive system was implemented to demonstrate the decoupling control of induction motors. >

High performance decoupling control techniques for various rotating field machines

Abstract: A comparative study of different field-oriented rotating-field machines is presented, including squirrel-cage induction machines, series-connected wound rotor induction machines, and synchronous machines. Evaluation of various field-oriented rotating-field machines for high-performance applications is presented. The concepts of torque linearization and decoupling control are studied and compared for various field-oriented motors. Computer simulations, experimental results, and space phasor diagrams are employed to illustrate the dynamics of decoupling control for the various field-oriented-control (FOC) systems. The control complexities and parameter sensitivities of various FOC drive motors are compared. >

Novel decoupled power flow

Abstract: A novel decoupled power flow method is reported, based on a novel decoupling form, and is developed for the purpose of obtaining best convergence. It is therefore referred to as the best in the novel decoupling form. The proposed method converges well not only on normal r/x ratio systems, but also on systems with high r/x ratio lines; the difficulties in convergence of decoupled power flow methods caused by high r/x ratio lines are overcome by the method proposed. Numerical results are presented to demonstrate the efficiency of the proposed method.

Parametrization of all decoupling compensators and all achievable diagonal maps for the unity-feedback system

Abstract: Decoupling in a linear, time-invariant (LTI), multi-input, multi-output (MIMO) unity-feedback system is considered. A parameterization is given of all stabilizing compensators which achieve decoupling in the unity-feedback system. It is assumed that the plant transfer-function, matrix is full row-rank and does not have unstable poles coinciding with zeros. >

Uncoupling the differential equations arising from a technique for evaluating indefinite integrals containing special functions or their products

Abstract: A previous article by Piquette and Van Buren [1] described an analytical technique for evaluating indefinite integrals involving special functions or their products. The technique replaces the integral by an inhomogeneous set of coupled first-order differential equations. This coupled set does not explicitly contain the special functions of the integrand, and any particular solution of the set is sufficient to obtain an analytical expression for the indefinite integral. It is shown here that the coupled set arising from the method always occurs in normal form. Hence, it is amenable to the method of Forsyth [6] for uncoupling such a set. That is, the solution of the set can be made to depend upon the solution of a single differential equation of order equal to the number of equations in the set. Any particular solution of this single equation is then sufficient to yield the desired indefinite integral. As examples, the uncoupled equation is given here for integrals involving (i) the product of two Bessel functions, (ii) the product of two Hermite functions, or (iii) the product of two Laguerre functions, and a tabulation of integrals of these types is provided. Examples involving products of three or four special functions are also provided. The method can be used to extend the integration capabilities of symbolic-mathematics computer programs so that they can handle broad classes of indefinite integrals containing special functions or their products.