Showing papers on "Decoupling (electronics) published in 1994"

High-performance induction motor control via input-output linearization

Abstract: We have shown that a current-command input-output linearization controller can achieve high-performance motion control, that is, the precise tracking of a fast point-to-point position reference. Specifically, this controller was shown to provide the means of decoupling the speed and flux dynamics in an induction motor. This decoupling of speed and flux was exploited to simultaneously track the position/speed reference and an optimal flux reference. This flux reference was used to obtain the optimal (max/min) motor torque at any given speed without violating voltage and current limits. Experimental results were presented to demonstrate the effectiveness of this scheme. >

Decoupling capacitor calculations for CMOS circuits

Abstract: CMOS circuits on printed circuit boards with continuous power planes require decoupling capacitors to keep power supply within specification, provide signal integrity and reduce EMC/EMI radiated noise. Capacitor values and quantities are calculated using time and frequency domain techniques.

Integrated decoupling capacitive core for a printed circuit board and method of making same

Abstract: A printed circuit board includes a planar first outer layer, a planar second outer layer, and a planar capacitive power distribution core disposed between the first and second outer layers. The capacitive core is formed from first and second electrically conductive layers with a dielectric layer disposed therebetween. The dielectric layer is made from a high dielectric constant material such as a ceramic in the form of a perforated sheet. The perforations permit the electrically conductive layers to be bound to the dielectric layer without significantly increasing the separation between the conductive layers. Each perforation allows a column of adhesive to collect therein to bond the power distribution core together. The resulting capacitance is typically sufficient to eliminate the need for decoupling capacitors.

Decoupling bandwidths for networks: a decomposition approach to resource management

Abstract: The authors consider buffer asymptotics for feed-forward networks shared by heterogeneous traffic streams. This is done by identifying the effective bandwidth of the departure processes from shared queues. They introduce the idea of decoupling bandwidths and constraints which guarantee "decoupled" asymptotics within the network. They discuss these results in the context of resource management for ATM networks. >

Adaptable wafer probe assembly for testing ICs with different power/ground bond pad configurations

Abstract: An adaptable probe card assembly for testing an IC die includes a probe card and a decoupling apparatus selectably mounted on the probe card. A different decoupling apparatus is used for each IC die to be tested having a different power and ground bond pad configuration. Each decoupling apparatus includes a conductive ground bus connected to ground, a nonconductive support structure, and a plurality of chip capacitors sandwiched between the conductive ground bus and nonconductive support structure in such positions that they are each connected at one end to the ground bus and at another end to one of the power or ground bond pads of the IC die being tested via a conductive contact extending through a hole in the nonconductive support structure down to a signal contact formed on the probe card, which signal contact is in turn, connected to a needle making touch contact with the appropriate power or ground bond pad of the IC die being tested.

Acoustical barrier with decoupler

Abstract: An acoustic barrier for mounting to a barrier wall, such as a barrier wall between an engine compartment and a passenger compartment of a vehicle. The barrier wall has multiple indentations forming an uneven surface. The acoustic barrier comprises a decoupling layer and a mass layer. The mass layer has a series of projections formed on a rear surface, which coincide with the indentations of the barrier. When the decoupling layer is mounted to the rear wall of the mass layer, the projections alter the shape of the decoupling layer to conform with the shape of the barrier layer.

Modeling power bus decoupling on multilayer printed circuit boards

Abstract: Power bus decoupling designs on multilayer printed circuit boards must adequately account for the power bus interplane capacitance and its consequences for the design. Lumped element models for a power bus on a multilayer printed circuit board where an appreciable or entire portion of a layer is devoted to power and ground have been developed. The models are applicable below the distributed resonances of the board. Analytical, circuit simulation, and experimental studies have been conducted to test the models, investigate the effects of the distributed interplane capacitance of the power bus, and the effect of interconnect inductance associated with surface-mount decoupling capacitors. >

Method and apparatus for repair of memory by redundancy

Abstract: A method of, and apparatus for, decoupling a defective or otherwise non-operational memory block from the power lines of a memory device is disclosed. Defects which cause excessive current consumption in defective memory blocks can be repaired through this approach. Mass-production yields can be improved significantly.

Robust Crossfeed Design for Hovering Rotorcraft

Abstract: Control law design for rotorcraft fly-by-wire systems normally attempts to decouple angular responses using fixed-gain crossfeeds. This approach can lead to poor decoupling over the frequency range of pilot inputs and increase the load on the feedback loops. In order to improve the decoupling performance, dynamic crossfeeds may be adopted. Moreover, because of the large changes that occur in rotorcraft dynamics due to small changes about the nominal design condition, especially for near-hovering flight, the crossfeed design must be 'robust.' A new low-order matching method is presented here to design robost crossfeed compensators for multi-input, multi-output (MIMO) systems. The technique identifies degrees-of-freedom that can be decoupled using crossfeeds, given an anticipated set of parameter variations for the range of flight conditions of concern. Cross-coupling is then reduced for degrees-of-freedom that can use crossfeed compensation by minimizing off-axis response magnitude average and variance. Results are presented for the analysis of pitch, roll, yaw, and heave coupling of the UH-60 Black Hawk helicopter in near-hovering flight. Robust crossfeeds are designed that show significant improvement in decoupling performance and robustness over nominal, single design point, compensators. The design method and results are presented in an easily-used graphical format that lends significant physical insight to the design procedure. This plant pre-compensation technique is an appropriate preliminary step to the design of robust feedback control laws for rotorcraft.

Noise-free analog islands in digital integrated circuits

Abstract: An integrated circuit chip has both digital and analog circuit functions, with one or more islands for isolating the analog functions from noise caused by the digital functions. An island is defined by a surrounding heavily-doped region in the face of the chip. The voltage supplies for an analog island are isolated from the digital supply voltage for high frequencies by using resistive decoupling in series along with capacitive coupling to ground. Similarly, series resistive decoupling and capacitive coupling to ground are employed for the analog input signal lines going to the island. Analog signals generated within the island are coupled to the area outside the island on the chip face by either converting to digital in an A-to-D converter, or by a differential arrangement which accounts for differences that may exist between digital and analog supply voltages. The differential circuit may have a pair of matched inputs, one side supplied by the analog voltage supply and the other by the digital voltage supply, and a differential amplifier generating the output signal and also fed back to the one side of the matched input.

Multi-cylinder internal combustion engine valve actuator

Abstract: In an apparatus for valve actuation in a multi-cylinder internal combustion engine, a valve is actuated by two actuation levers which can be coupled together by coupling elements. The actuation levers are driven by two cams with different cam protrusions. In order to avoid wear-causing incomplete coupling for all the coupling elements when the cam protrusions become effective, their triggering for coupling and decoupling only takes place within an interval of time fixed with respect to the camshaft position. When the cam protrusions become effective, the coupling or decoupling procedure is either concluded or at least a sufficient overlap of the coupling elements is produced.

Linear multichannel control: a system matrix approach

Abstract: Linear matrix equations fractional representations internal stability disturbance decoupling problem regulator problem decentralized stabilization problem non-interacting control problem almost decoupling and non-interacting control.

Mixed-signal noise-decoupling via simultaneous power distribution design and cell customization in RAIL

Abstract: An important and largely unexplored aspect of power distribution synthesis is cell customization. Through cell customization, power I/O cell assignments and local substrate and power supply decoupling may be tailored to reduce deleterious noise effects on analog circuits in mixed-signal environments. In this paper, we describe techniques for simultaneous power grid design (topology and sizing) and cell configuration/customization which allow designers to handle more difficult chip-level noise problems. We have incorporated this new approach in the power distribution synthesis tool RAIL and demonstrate its effectiveness on an industrial mixed-signal example. >

Low jitter ring oscillators

Abstract: Low jitter ring oscillators are disclosed. The oscillators obtain their low jitter through the use of gates (100) and interpolators (160) having time delays of superior stability. The stability is obtained with decoupling networks (140) and delay replica generators (222) that isolate power supply noise from critical circuit parameters.

Decoupling of linear systems with delays

Abstract: The aim of this paper is to exhibit necessary and sufficient conditions for the decoupling problem of linear systems with commensurate delays, under static nonpredictive state feedbacks. Moreover we give the only possible design of the physically realizable control law that satisfies the problem. >

The nonlinear interactor and its application to input-output decoupling

Abstract: The solvability of the input-output decoupling problem via pure dynamic state feedback, a special type of dynamic compensator without zeros at infinity, is investigated. A necessary and sufficient condition for the solvability of this problem is established in terms of a nonlinear interactor, a new concept in the theory of nonlinear control. >

Transfer Function Approach to Disturbance Decoupling Problem

Abstract: We give a necessary and sufficient condition for existence of a controller which decouples the disturbance signal. The condition is based on state space computations. If it is satisfied, we parametrize the set of all disturbance decoupling controllers.

Power electronic design and layout techniques for improved performance and reduced EMI

Abstract: This paper describes how the physical layout and routing of power electronic circuits affects circuit performance, and influences EMI/RFI generation. Three categories of common circuit board layout effects are presented: impedance effects, capacitively induced effects, and inductively coupled effects. Guidelines are presented to determine the bandwidth of the signals of interest, along with methods for determining appropriate conductor geometries. Capacitor selection for decoupling, bypassing, and snubbing is also discussed.

CMOS integrated circuit having improved power-supply filtering

Abstract: An important problem in large integrated circuits is constituted by noise superimposed on the supply. This noise is particularly caused by switching of switching elements such as flipflops, and by heavily loaded output stages. These elements cause current peaks which may give rise to comparatively great fluctuations in voltage. This problem is solved at least to a great extent in CMOS circuits with standard cells or with custom layout blocks by means of an additional decoupling capacitance in the form of an extra well in the routing channels. The decoupling capacitance may be positioned immediately adjacent the switching element, which is favorable for suppressing the supply noise. Since the routing channels are generally not used for providing circuit elements, the chip surface area is not or substantially not increased by this extra capacitance.

Modelling and simulation of integral decoupling capacitors in single and multichip module electronics packaging

Abstract: In high-end packaging structures, switching currents of short pulse width and high clock rate generate significant Delta-I noise which can cause malfunctions of IC circuits. The trend of increasing packing density makes the integral decoupling capacitor preferable than the conventional discrete capacitor. Although integral decoupling capacitors have been proposed and already used in some packaging structures, their electrical performance has not been accurately modeled. This paper presents an efficient and accurate numerical technique for the simulation of Delta-I noise in multi-layer power and ground plane packaging structures containing integral decoupling capacitors. Various factors that determine the effectiveness of integral decoupling capacitors, such as their geometries and locations in packaging structures, are also studied. >

Storage case for computer cards

Abstract: A multiple section card case for storing computer cards, such as PCMCIA cards. The multiple section card case includes a top piece, a bottom piece, and a plurality of intermediate pieces interchangeably coupled to each other. When coupled together, the top, bottom, and intermediate pieces form a plurality of card storage sections that may be independently accessed. Each case section may be opened or closed by rotating adjacent pieces forming the section away from or toward each other. Case sections may be removed or added by decoupling an intermediate piece and then adding or removing intermediate pieces.

EMI test system and decoupling network therefor, the decoupling network having series connected resonators with torroidal cores formed from a ferrite Composition

Abstract: Development of worst case operating environment, interfering parameters of a test item, is effected by a decoupling device. The device includes a series of resonators configured and interconnected in a particular manner along with a shunt capacitance. Each resonator has a torroidal core formed from a ferrite composition. When connected between the test item and its support system, the device provides such an impedance to signals other than those needed for normal operation, that the highest noise voltage levels emit from the test item. These levels permit developing repeatable worst case interference parameters which provide a guide for modifying the test item circuit components and connectors so as to minimize the effects of generating EMI sources or to immunize susceptible receptors within the test item.

Decoupling Sales Law from the Acceptance- Rejection Fulcrum

Abstract: 1. BURDEN OF PROOF AND THE ACCEPTANCE-REJECTION FULCRUM .......... 135 A. Decoupling Burden-of-Proof fron Salvage Rules ................. 138 B. An Efficiency Analysis of the Code's Allocation of Burden of Proof .... 141 1. The Access-to-Evidence Rationale for Allocating Burden of Proof . . 142 a. Access to Evidence as Access to the Goods .............. 143 b. Access to Evidence as Access to Inspection Evidence ........ 144 2. Allocating Burden of Proof to the Cheapest Producer of Cost-Effective Evidence ............................... 146 3. Allocating Burden of Proof Against the Party Likely To Be Asserting a False Claim .......................... 148 4. Summary ........................................... 150 C. Conclusion ............................................ 152

Circularly polarised local antenna arrangement for nuclear spin tomography appts. - has array of three or more linearly polarised coils overlapped to achieve geometric decoupling.

Abstract: The antenna arrangement consists of an array of at least three linearly polarised local coils (20-23) which overlap each other to the extent that they are geometrically decoupled. Each local coil is separately connected to a combination network (36). The network performs a complex combination of the output signals of the three local coils resulting in high frequency output signals (b5,b6) which represent circular polarisations. USE/ADVANTAGE - For nuclear spin tomography device. Antenna arrangement is designed for problem-free decoupling between individual elements.

Fuel line disconnect tool

Abstract: A semi-cylindrical tool for decoupling telescoping tubular members includes two companion, opposed semi-cylindrical engaging sections each joined to an elongated arm which, in turn, is attached to a single handle. The elongated arms are flexible and permit access of the tool into difficult to reach places.