Showing papers on "Decoupling (electronics) published in 2000"

Robust control with decoupling performance for steering and traction of 4WS vehicles under velocity-varying motion

Abstract: This paper mainly studies robust steering and traction of four-wheel steering (4WS) vehicles with varying velocity, mass, moment of inertia, and road-tire interaction. To this end, a nonlinear vehicle model is developed which both takes the acceleration and braking effects on the system dynamics into account and avoids using the complicated side force relation. Based on this model, a nonlinear input-output decoupling controller is first designed, by which the vehicle system can be decoupled into three two-order subsystems, i.e., the velocity subsystem controlled by the longitudinal acceleration/braking force, the lateral motion subsystem by the front steering angle, and the yaw motion subsystem by the rear steering angle, so that the load of the driver can be relieved. Especially, a new decoupling condition is derived. It is proved that a vehicle with the front wheel braking or rear wheel drive can always be decoupled provided it does not accelerate so fast or brake so hard that its front or rear wheels are lifted from the ground. Furthermore, in order to reduce the effects of the vehicle parameter variations on steering performance, a robust control scheme is proposed. The corresponding controller and observer gains can be obtained by solving two new Riccati algebraic equations. Meanwhile, by properly choosing the form of the observer, the robust controller does not destroy the decoupling structure of the longitudinal and yaw motions. The numerical simulation shows that the robust control with decoupling performance can improve safety and comfort of the vehicle driving.

Active suspension control of ground vehicle based on a full-vehicle model

Abstract: An active suspension control approach combining a filtered feedback control scheme and an "input decoupling transformation" is given for a full-vehicle suspension system. Motions of the sprung mass (car body) above and below the wheel frequency modes are mitigated by using active filtering of spring and damping coefficients through inner control loops (ride controller) plus skyhook damping of heave, pitch and roll velocities through outer control loops (attitude controller). The inner ride control loops and the outer attitude loops are blended with the input decoupling transformation. The performance of the active suspension control is demonstrated in simulations.

Measuring, modeling and decoupling of saturation-induced saliencies in carrier signal injection-based sensorless AC drives

Abstract: The focus of this paper is the measuring, modeling, and decoupling of saturation-induced saliencies in carrier-signal injection-based sensorless control. First, techniques for the measurement of saturation-induced saliencies are presented. The goal of these measurements is to provide useful information on the position and magnitude of the various saturation-induced saliencies. Using the results from several different experimental measurements, models are developed explaining the source and behavior of the saturation-induced saliencies. The paper concludes by presenting methods for decoupling the effects caused by the parasitic saturation-induced saliencies, eliminating the errors that they cause in rotor position or flux angle estimation.

An on-chip voltage regulator using switched decoupling capacitors

Abstract: On-chip decoupling capacitors are actively switched to suppress resonance in the power distribution system of a microprocessor. With this scheme, charge storage capacity is amplified, while instantaneous monitoring of rail activity and dynamic control of the switching response provide bandlimited on-chip voltage regulation.

Multi-functional energy conditioner

Abstract: The present invention relates to a multi-functional energy conditioner having architecture employed in conjunction with various dielectric and combinations of dielectric materials to provide one or more differential and common mode filters for the suppression of electromagnetic emissions and surge protection. The architecture allows single or multiple components to be assembled within a single package such as an integrated circuit or connector. The component's architecture is dielectric independent and provides for integration of various electrical characteristics within a single component to perform the functions of filtering, decoupling, fusing and surge suppression.

On-chip decoupling capacitor optimization using architectural level prediction

Abstract: Switching activity-generated power-supply grid-noise presents a major obstacle to the reduction of supply voltage in future generation semiconductor technologies. A popular technique to counter this issue involves the usage of decoupling capacitors. This paper presents a novel design technique for sizing and placing on-chip decoupling capacitors based on activity signatures from the microarchitecture. Simulation of a typical processor workload (SPEC95) provides a realistic stimulation of microarchitecture elements that is coupled with a spatial power grid model. Evaluation of the proposed technique on typical microprocessor implementations (the Alpha 21264 and the Pentium II) indicates that this technique can produce up to a 30% improvement in maximum noise levels over a uniform decoupling capacitor placement strategy.

Model and analysis for combined package and on-chip power grid simulation

Abstract: We present new modeling and simulation techniques to improve the accuracy and efficiency of transient analysis of large power distribution grids. These include an accurate model for the inherent decoupling capacitance of non-switching devices, as well as a statistical switching current model for the switching devices. Moreover, three new simulation techniques are presented for problem size-reduction and speed-up. Results of application of these techniques on three PowerPC/sup TM/ microprocessors are also presented.

Multi-machine multi-converter system for drives: analysis of coupling by a global modeling

Abstract: More and more electrical systems are composed of several electrical machines and several electrical and/or mechanical converters. Such systems are called multi-machine multi-converter systems (MMS) and are described by a specific formalism. Specific coupling structures are defined in order to distribute the energy. Three coupling structures are pointed out in drive applications: electrical, magnetic and mechanical coupling devices. Despite allowing a better energy distribution, these coupling structures also induce also some constraints on power components and some perturbations between the associated conversion chains. Decoupling control strategies may be developed in order to minimize these interactions. Three examples of the different couplings are presented according to this specific formalism.

Method and means for decoupling a printed circuit board

Abstract: An improved method and means for decoupling a printed circuit board are disclosed. A power plane is included having a peripheral edge. The power plane includes a first region and a second region which is separate from and contiguous to the first region. The first region is located from the peripheral edge to a middle portion of the power plane. The first region includes a peripheral portion of the power plane. The second region includes only the middle portion of the power plane. A ground plane is coupled in parallel to the power plane. The ground plane has a peripheral edge. The ground plane includes a first region, and a second region which is separate from and contiguous to the first region. The first region includes the peripheral edge and includes a peripheral portion of the ground plane. The second region includes a middle portion of the ground plane. A first plurality of decoupling elements are connected to the first region of the power plane and to the first region of the ground plane. A second plurality of decoupling elements are connected to the second region of the power plane and to the second region of the ground plane. The first and second plurality of decoupling elements are utilized to decouple the power plane and ground plane pair.

Dynamic decoupling and compensating methods of multi-axis force sensors

Abstract: Dynamic decoupling and compensating methods of multi-axis force sensors are proposed to solve simultaneously the dynamic coupling between axes and the slow dynamic response which are the two key problems in dynamic characterizing of the multi-axis force sensors and improve their dynamic quality. Four types of dynamic decoupling and compensating networks are shown, the design equations and procedures are presented, and the parameters of the networks are determined using a method based on a functional link artificial neural network (FLANN). The dynamic decoupling and compensating results for a wrist force sensor have proved the methods to be correct and effective.

A methodology for the placement and optimization of decoupling capacitors for gigahertz systems [CMOS VLSI]

Abstract: This paper discusses a method for computing the effect of decoupling capacitors on the power delivery system for gigahertz packages and boards. A fast and accurate computational method is presented that can be used to estimate the amount of decoupling required, the type of capacitor to be used and its location (on-chip, package or board).

Dashmat with an air distribution system

Abstract: A dashmat for use in a vehicle passenger compartment comprising a firewall separating the passenger compartment from an engine compartment and a floorboard extending rearwardly from the firewall. The dashmat comprises a decoupling layer shaped to span the width of the vehicle passenger compartment. The decoupling layer has a lower surface adapted to abut the firewall and floorboard, and an upper surface adapted to face an interior of the passenger compartment. A header is formed in a front portion of the decoupling layer and is adapted to connect to a supply duct from a vehicle HVAC system. An air distribution channel is formed in the decoupling layer and extends rearwardly from the header through a substantial portion of the decoupling layer for distribution of conditioned air from the header throughout at least a front portion of the vehicle passenger compartment.

Efficient and accurate modeling of power supply noise on distributed on-chip power networks

Abstract: In this paper, we propose an efficient and accurate modeling technique for power supply noise estimation over on-chip power lines which are modeled as distributed RCL networks. With this model, peak noise on the power lines that includes on-chip resistive and inductive voltage drops, switching noise on packages, and on-chip decoupling effects, can be computed very efficiently and accurately. The model is verified by SPICE simulations.

Design and performance evaluation of microprocessor packaging capacitors using integrated capacitor-via-plane model

Abstract: As clock speeds increase into the gigahertz regime and rise times decrease into the picosecond regime, the interaction between capacitors and power/ground planes of a package, interposer, or board on which they are mounted becomes vitally important to the performance of a power delivery system. To include the interaction, this paper provides an integrated model for a discrete capacitor mounted on pads over vias connected to power/ground planes with degassing holes. The mutual inductance between capacitor pads, vias, and power/ground planes are completely modeled. Through optimized via and capacitor pads placement designs, our modeling results show that the mutual inductance drastically changes the total loop inductance as compared to the self-inductance of the capacitor. To validate the integrated modeling method, a test package is built. A measurement technique is introduced to evaluate the total loop inductance of the test package with various capacitor form factors and types. The predicted results match well with the measured data. This paper discusses further the usage of the three-dimensional (3-D) integrated model for actual implementation of decoupling capacitors on packages in order to ensure the effectiveness of the capacitors. The first decoupling capacitor placement design on package that we will discuss is the Plastic Pin Grid Array (PPGA) package for Intel's CPU. Through the three-dimensional (3-D) integrated modeling, the inductance value of the power delivery system with and without capacitors are extracted. It was found that due to the pin-out constraint of CPU PPGA products, as well as unfavorable PPGA package design rules, decoupling capacitors placed in PPGA packages are not effective due to high loop inductance. The second package that we will discuss is the Flip Chip Pin Grid Array (FC-PGA) package, which is for Intel's future CPU packaging. It is found that the decoupling capacitor placement on the FC-PGA highly improves the performance of the power delivery system. For the same amount of cost, the total loop inductance for FCPGA package decoupling capacitors is found to be 1/9th the total loop inductance for the PPGA package.

Quantifying decoupling capacitor location

Abstract: The decoupling capacitor location in DC power bus design is a critical design choice for which proven guidelines are not well established. The mutual inductance between two closely spaced vias can have a great impact on the coupling between an IC and a decoupling capacitor. This coupling is a function of the spacing between the IC and capacitor, and spacing between power and ground layers. The impact of the mutual inductance on decoupling, i.e., local versus global decoupling, was studied, using a circuit extraction approach based on a mixed-potential integral equation. Modeling indicates that local decoupling has benefits over global decoupling for certain ranges of IC/capacitor spacing and power layer thickness. Design curves for evaluating local decoupling benefits were generated, which can be used to guide surface mount technology (SMT) decoupling capacitor placement.

Application of direct bias control in high-density inductively coupled plasma etching equipment

Abstract: The use of a novel method of power delivery control at the wafer chuck in a high-density inductively coupled plasma reactor has been investigated. This method involves using a peak voltage sensor mounted immediately below the chuck in a feedback loop to the rf generator such that the rf peak voltage can be set as a recipe parameter. By controlling the power delivery in this manner, it is demonstrated that the effects of power losses in the rf circuit between the generator and the chuck, especially in the match network, can be compensated for. In addition, the effect of interactions among source power, bias power and other process parameters on sheath voltage can also be eliminated. In this manner a more complete decoupling of plasma density and ion energy can be achieved than more conventional methods of power delivery allow.

Acoustic radiation from an elastic baffled rectangular plate covered by a decoupling coating and immersed in a heavy acoustic fluid

Abstract: The vibroacoustic behavior of an elastic, simply supported rectangular plate covered by a locally reacting decoupling layer supporting thickness deformation is presented. The model simulates the vibration and acoustic response of the system immersed in water and subjected to a point force disturbance. A simplified version of the theory is derived in the limiting case of a large decoupling (low mechanical impedance of the layer/high frequency). An appropriate vibratory indicator, representative of the acoustic attenuation provided by the decoupling treatment, and independent of the structure dimensions, is also investigated from the perspective of small-scale laboratory characterization

SAR and temperature changes in the leg due to an RF decoupling coil at frequencies between 64 and 213 MHz.

Abstract: Specific absorption rate (SAR) due to a butterfly surface coil in a realistic model of the leg was calculated for frequencies 64 or = 149 MHz. The corresponding maximum deltaT at 64, 128, and 213 MHz were 0.3, 1.3, and 5.0 degrees C, respectively.

Crane automation by decoupling control of a double pendulum using two translational actuators

Abstract: Modeling a crane as a double pendulum enables control of the position as well as the tilt of the load. Using the trolley motion and an additional translational actuator at the load suspension unit as system inputs, a control structure is described, that achieves damping of sway and tilt oscillations and establishes a decoupling between position and tilt angle of the load. These control features are the foundation for using the crane as a large workspace covering robot with six degrees of freedom. State space methods are used to design the decoupling control. Experimental results on a 5 ton bridge crane with workspace dimensions of 30 m/spl times/9 m/spl times/7 m show the performance of the presented concept.

Digital circuit decoupling for EMI reduction

Abstract: A printed circuit board assembly characterized by at least two decoupling capacitors for decoupling transient currents resulting from, for example, logic transitions in high-speed digital circuitry. The decoupling capacitors are physically arranged, and electrically connected between a power plane and a ground plane, so that transient currents flow in respectively opposite directions through the capacitors, thereby maximizing the capacitors' mutual inductance, and thus minimizing the electromagnetic interference generated by the capacitors.

A study of the high frequency performance of thin film capacitors for electronic packaging

Abstract: The provision of adequate decoupling capacitance in the power distribution system for integrated circuits (ICs) is an increasing concern. As clock rates and the IC gate density increase, discrete chip capacitors do not satisfy the decoupling requirements for high current switching at very high frequencies. Thin film capacitors not only exhibit better high frequency performance than discrete ceramic capacitors, but also provide the possibility for passive component integration. In this work, the high frequency performance of thin film capacitors was investigated using Maxwell Eminence, a high frequency structure simulator based on the finite element method. Good agreement between the calculated impedance and experimental results was obtained. At high frequencies, the performance of thin film capacitors is related to contact configurations, dielectric and metal layer thicknesses, and capacitor shapes. The influence of these factors on the impedance behavior was examined. Equivalent circuits of a thin film capacitor for use in a circuit simulator at high frequencies are discussed.

System and method for determining the desired decoupling components for a power distribution system having a voltage regulator module

Abstract: A system and method for determining the desired decoupling components for a power distribution system having a voltage regulator module. The system may employ a mathematical model of a voltage regulator circuit, such as a switching voltage regulator. The mathematical model may be a SPICE model, or a circuit model in another format. The method may include simulating the operation of the power distribution system to obtain a estimate of the bulk capacitance required for effective decoupling. For digital systems, the method may include a cycle-by-cycle simulation of the power distribution system, wherein the simulation occurs over a number of clock cycles. The performance of the power distribution system may then be analyzed for each simulated clock cycle. The simulation may also include analyzing the transient responses and loop stability of the power distribution. Based on the results of these various simulations, the bulk capacitance value may be refined, thus allowing the system to begin the selection of specific decoupling components from the database in order to satisfy the bulk capacitance requirements.

Bias circuit for series connected decoupling capacitors

Abstract: A semiconductor circuit for providing decoupling capacitance to an integrated circuit voltage supply that includes a decoupling capacitance comprised of an array of memory cells connected in series at a node and a source of biasing voltage connected to the array of memory cells at the node for maintaining the voltage level at the node lower than the voltage level of the voltage supply.

An optimization method for placement of decoupling capacitors on printed circuit board

Abstract: This paper investigates the optimal placement of decoupling capacitors on printed circuit boards (PCB). This method minimizes the impedance characteristics at the power supply in the specified frequency range in order to find the optimal decoupling capacitor position. In this method, the PCB is modeled via the partial element equivalent circuit (PEEC) model approach to handle the 3D structures, and the Krylov-subspace technique is used to obtain the impedance characteristics in the frequency domain efficiently.