Showing papers on "Decoupling (electronics) published in 2003"

Arranging language features for more robust pattern-based crosscuts

Abstract: A crosscut language is used to describe at which points an aspect crosscuts a program. An important issue is how these points can be captured using the crosscut language without introducing tight coupling between the aspect and the program. Such tight coupling harms the evolvability of the program and the reusability of the aspect. Current pattern-based capturing already offers a certain decoupling between aspects and the program but it may still suffer from what we call the arranged pattern problem. In this paper, we discuss this problem and present a logic-based crosscut language from which we distill what language features are beneficial to avoid this problem.

Optimal decoupling capacitor sizing and placement for standard-cell layout designs

Abstract: With technology scaling, the trend for high-performance integrated circuits is toward ever higher operating frequency, lower power supply voltages, and higher power dissipation. This causes a dramatic increase in the currents being delivered through the on-chip power grid and is recognized in the 2001 International Technology Roadmap for Semiconductors as one of the difficult challenges. The addition of decoupling capacitances (decaps) is arguably the most powerful degree of freedom that a designer has for power-grid noise abatement and is becoming more important as technology scales. In this paper, we propose and demonstrate an algorithm for the automated placement and sizing of decaps in application specific integrated circuit (ASIC)-like circuits. The problem is formulated as one of nonlinear optimization and is solved using a sensitivity-based quadratic programming (QP) solver. The adjoint sensitivity method is applied to calculate the first-order sensitivities. We propose a fast convolution technique based on piecewise linear (PWL) compressions of the original and adjoint waveforms. Experimental results show that power grid noise can be significantly reduced after a judicious optimization of decap placement, with little change in the total chip area.

Power-bus decoupling with embedded capacitance in printed circuit board design

Abstract: This paper experimentally investigates the effectiveness of embedded capacitance for reducing power-bus noise in high-speed printed circuit board designs. Boards with embedded capacitance employ closely spaced power-return plane pairs separated by a thin layer of dielectric material. In this paper, test boards with four embedded capacitance materials are evaluated. Power-bus input impedance measurements and power-bus noise measurements are presented for boards with various dimensions and layer stack ups. Unlike discrete decoupling capacitors, whose effective frequency range is generally limited to a few hundred megahertz due to interconnect inductance, embedded capacitance was found to efficiently reduce power-bus noise over the entire frequency range evaluated (up to 5 GHz).

Sliding modes in power electronics and motion control systems

Abstract: In this paper the concepts, design aspects and application of Sliding Mode Control (SMC) systems to power electronics and motion control systems are discussed. The salient features of the Variable Structure Systems (VSS) with sliding modes are order reduction, decoupling in the design procedure, insensitivity in plant parameter changes and disturbances rejection. Simple implementation makes concepts of SMC very attractive in power electronics and motion control systems. Application to problems like control of DC and AC converters, the control of electrical machines and the design of the observers for electrical machines are discussed.

Decoupling based Cartesian impedance control of flexible joint robots

Abstract: This paper addresses the impedance control problem for flexible joint manipulators. An impedance controller structure is proposed, which is based on an exact decoupling of the torque dynamics from the link dynamics. A formal stability analysis of the proposed controller is presented for the general tracking case. Preliminary experimental results are given for a single flexible joint.

Pipeline muffling and a priori current ramping: architectural techniques to reduce high-frequency inductive noise

Abstract: While circuit and package designers have addressed microprocessor inductive noise issues in the past, multi-gigahertz clock frequencies and billion-transistor-level integration are exacerbating the problem, necessitating microarchitectural solutions. The large net on-die decoupling capacitance used to address this noise throughout the chip consumes substantial area and can cause a large leakage current. This paper proposes microarchitectural techniques to reduce high-frequency current variability, reducing the need for decoupling capacitors. We observe that we can control inductive noise by reducing current variability either in space (i.e., variability in usage of circuit blocks) or in time (i.e., variability within a circuit block across clock cycles). We propose pipeline muffling, a novel technique to reduce changes in the number of resources being utilized by controlling instruction issue, trading off some energy and performance to control di/dt in space. We also extend a previous technique, which incurs performance and energy degradation, and propose a priori current ramping to allow the current of a resource to ramp up ahead of usage, with virtually no performance loss, and ramp down immediately after usage, with little energy loss. Our techniques guarantee a worst-case bound on the di/dt, which is required to reduce the demand for decoupling capacitors, saving area and reducing leakage.

Flaw detection in objects and surfaces

Abstract: The invention relates generally to the simultaneous acquisition of superimposed color dark-field and light-field images with a camera followed by decoupling of the images into monochrome components for further analysis of surface defects.

Method for bus capacitance reduction

Abstract: Data bus capacitance is reduced by decoupling unaccessed memory circuits from a data bus during data transfers to or from other memory circuits.

Pipeline damping: a microarchitectural technique to reduce inductive noise in supply voltage

Abstract: Scaling of CMOS technology causes the power supply voltages to fall and supply currents to rise at the same time as operating speeds are increasing. Falling supply voltages cause noise margins to decrease, while increasing current and frequency makes supply noise injection larger, especially noise caused by inductance in the supply lines. Creating power distribution systems is one of the key challenges in modern chip design. Decoupling capacitance helps reduce inductance effects, but there is often a peak in the supply impedance that occurs at a resonant frequency caused roughly by the package inductance and the chip decoupling capacitors. This frequency is on the order of 100MHz, which is much lower than the operating frequency of the processor. We propose pipeline damping, an architectural technique which controls instruction issue to guarantee bounds on current variation around the frequency of the supply resonance, thus reducing the resulting supply noise. Damping is a cheaper alternative to expensive, circuit-based noise-reduction techniques. We make the fundamental observation that limiting the current flow change (di) within resonant time period (dt) controls di/dt without large performance loss. Damping guarantees bounds on current variation while allowing processor current to increase or decrease to the magnitude required to maintain performance. Our results show that a damped processor guarantees a 33% reduction in the worst-case current variation with an average performance degradation of 7% and average energy delay of 1.09 compared to an undamped processor.

On-chip decoupling capacitor optimization for noise and leakage reduction

Abstract: The on-chip decoupling capacitors are widely used in today's high-performance microprocessor design to mitigate the power supply noise problem. The continued reduction of oxide thickness in advanced nanotechnology, however, also significantly increases the tunneling current and leakage power of thin-oxide capacitors. This paper describes the modeling and simulation of a complete chip and package power supply distribution network, and the optimization of the placement of thin-oxide and thick-oxide capacitors to reduce the tunneling current, leakage power, and burn-in cost, while limiting the power supply noise within noise margin.

Surge protection device and method

Abstract: A device and method are disclosed for protecting a wireless communication system from impulse surges occurring in the system under the impact of lightning discharges. The device includes a high frequency line, and a first decoupling filter formed as a λ/4 section and a gas arrestor, sequentially connected to the high frequency line, in which the gas arrestor is connected between the first decoupling filter and the ground. A low frequency line and a second decoupling filter are connected in series between an output terminal, through which a signal flows into a circuit, and a contact point between the first decoupling filter and the gas arrestor. The low frequency line includes a low voltage limiter and a low pass filter. A T-shaped high pass filer is connected to the high frequency line.

Encoded recoupling and decoupling: An alternative to quantum error-correcting codes applied to trapped-ion quantum computation

Abstract: A recently developed theory for eliminating decoherence and design constraints in quantum computers, ``encoded recoupling and decoupling,'' is shown to be fully compatible with a promising proposal for an architecture enabling scalable ion-trap quantum computation [D. Kielpinski et al., Nature (London) 417, 709 (2002)]. Logical qubits are encoded into pairs of ions. Logic gates are implemented using the S\o{}rensen-M\o{}lmer (SM) scheme applied to pairs of ions at a time. The encoding offers continuous protection against collective dephasing. Decoupling pulses, that are also implemented using the SM scheme directly to the encoded qubits, are capable of further reducing various other sources of qubit decoherence, such as due to differential dephasing and due to decohered vibrational modes. The feasibility of using the relatively slow SM pulses in a decoupling scheme quenching the latter source of decoherence follows from the observed $1/f$ spectrum of the vibrational bath.

Interference signal decoupling on a printed circuit board

Abstract: A decoupling circuit on a printed circuit board is disclosed. The decoupling circuit comprises an electrical filter circuit electrically connected between an interconnect post and a ground land of the printed circuit board. The ground land is connected to a ground plane in the printed circuit board. The electrical filter shunts conducted interfering signals received at the interconnect post to the ground plane. Components of the electrical filter circuit and ground plane form a first receiver loop in which induced interfering signals can be generated. The decoupling circuit also comprises a second receiver loop comprising a conductive coating of an EMI shield conformingly adhered to surfaces of the decoupling circuit, and a conductive path of the first receiver loop. The second receiver loop is adapted to have induced therein a signal having a direction and magnitude sufficient to cancel interfering signals induced in the first receiver loop.

Cross-coupling of the oscillation modes of vibratory gyroscopes

Abstract: This paper reports for the first time on the results of the advanced gyroscope design of HSG-IMIT with the double decoupling mechanism. In connection with the measurement results, particularly to characterize the effectiveness of the decoupling, the cross-coupling of the driven oscillation and the detection oscillation is investigated, discussed and evaluated in detail by theoretical modeling. A description of the measurement signal and the so-called quadrature signal is deduced and a comparison with the gyroscopes of HSG-IMIT realized according to the single decoupling principle DAVED is accomplished.

Nonlinear control and disturbance decoupling of an HVAC system via feedback linearization and back-stepping

Abstract: In this paper a backstepping controller for a nonlinear, MIMO HVAC system is introduced Feedback linearization method with introduction of a feedback of states and disturbances is used for the purposes of disturbance decoupling and nonlinear model linearization The backstepping controller is applied to the linearized model of the system It is shown that by this method, heat and moisture loads can be compensated, considering them as measurable disturbances In this way the system can adapt itself to load variations fast and without any offset Finally the simulation results are brought to show the ability of the method to present a controller with high disturbance decoupling and good tracking properties

On-package decoupling optimization with package macromodels

Abstract: Suppressing clock-gating-induced noise at the chip-package interface is one of the most challenging power distribution integrity issues. In this paper, accurate and efficient assessment of the effectiveness of on-package decoupling is facilitated by package macromodels which compactly represent packaging parasitics among multiple on-package decoupling and on-chip ports. Based on such assessment, a simulated-annealing-based optimization procedure is developed with the goal of finding the most cost-effective on-package decoupling while meeting the noise budget.

Methods and apparatus for current control of a three-phase voltage source inverter in the overmodulation region

Abstract: A drive system that is suitable for high bandwidth current control of a three-phase voltage source inverter in the overmodulation region includes a feedback path that has a harmonic decoupling block that subtracts selected harmonic components from signals representative of a corresponding motor phase current signal. The harmonic decoupling block thereby generates corrected feedback signals. The drive system also includes subtractor blocks that subtract the corrected feedback signals from signals representative of open-loop magnetizing reference currents to generate difference signals. Also included is a modulation block that utilizes the difference signals to produce signals to drive a three-phase voltage source inverter in an overmodulated six-step mode.

Decoupling economic activity and transport growth: the state of play in New Zealand

Abstract: The Ministry of Transport's December 2002 New Zealand Transport Strategy states that "in the long run, economic development and transport growth need not be directly related". That is, it suggests that in the long run, there may be some 'decoupling' of economic growth and transport growth. This paper aims to 'start the ball rolling' on decoupling issues amongst the New Zealand research community. This paper comprises two key sections. First the authors examine the international literature on decoupling in order to gain an understanding of how this issue has been addressed overseas. The key conclusions from the literature review are that decoupling is poorly defined and that quantitative analysis surrounding the topic is scant. They then move on to analyse some possible measures of decoupling in New Zealand. Whilst the results are interesting, they highlight the need to clearly define decoupling before attempting to develop measures to accurately monitor it. The paper concludes by suggesting one possible definition and monitoring measure of decoupling. (a) For the covering entry of this conference, please see ITRD abstract no. E210413.

Decoupling element of deformable material in a power transmission system

Abstract: The invention seeks to improve the transfer function of drive devices such as pulleys and other coupling means, and it proposes creating zones of shear in the inserted deformable material forming a decoupling element. In an embodiment, the decoupling element is made in the form of a ring ( 2 ) presenting at least one meshing face ( 21 e , 21 i ) complementary to a corresponding meshing face ( 31, 41 ) formed on the facing support ( 3, 4 ), the meshing projections ( 2 e , 2 i , 3 e , 4 i ) engaging in one another to take up power transmission torque by working in shear by being blocked against each other during rotation. The invention is applicable to all drive devices including a filtering, damping, or absorbing element, e.g. for use in the automotive industry.

Decoupling capacitance estimation and insertion flow for ASIC designs

Abstract: A method for estimating decoupling capacitance during an ASIC design flow is disclosed. The method includes precharacterizing a set of power grid structures to model their respective noise behaviors, and storing the respective noise behaviors as noise factors in a table. During the ASIC design flow for a current design that includes at least one of the precharacterized power grid structures, the corresponding noise factor from the table is used to calculate decoupling capacitance for the current design.

Optimized design of MOS capacitors in standard CMOS technology and evaluation of their Equivalent Series Resistance for power applications

Abstract: An analytical study of the MOSFET-based capacitor is presented. This highly dense capacitive structure, suited to integrated circuits, is studied specifically for power applications by providing design guidelines for achieving minimum equivalent series resistance (ESR). The work includes layout strategies in standard digital CMOS technologies to provide optimal ESR, a design procedure for a target impedance at a given frequency, as well as a performance comparison with other on-chip capacitive structures such as poly-poly and metal-metal capacitors. The results are applicable for on-chip power circuits such as output filter stages in future integrated switching power converters, switched capacitor power converters, or decoupling circuits in high-performance on-chip power distributing networks.

Dynamically adjustable decoupling capacitance to reduce gate leakage current

Abstract: A new method to reduce switching noise on an integrated circuit device is achieved. The method comprises providing an integrated circuit device comprising a power supply, a ground, and a plurality of switchable capacitors. Each switchable capacitor is connected from the power supply to ground. The operating mode of the integrated circuit device is tracked. An optimal capacitance value is selected based on the operating mode. A set of switchable capacitors from the plurality of switchable capacitors is selected to thereby connect the optimal capacitance value from the power supply to ground.

Control of a pressure tank system using a decoupling control algorithm with a neural network adaptive scheme

Abstract: The design of a multivariable adaptive decoupling controller and its application to a real-time pressure tank system is presented. The pressure tank is highly coupled and nonlinear. The developed algorithm allows the noise disturbance to be coloured and uses a modification of the Hopfield neural network to identify and track the system parameters. The control algorithm is tested, first in a simulation using an identified model and secondly in a real-time application to a pressure tank system. A very good control performance is reported.

Method for controlling plate sizes of middle or thin plate planks in continuous casting and rolling processes

Abstract: An integrated control method for the shape of medium-thin plate in conticasting and tandem rolling includes finishing shape setting control model, automatic thickness control AGC, the affection of laminar flow cooling to plate shape, and use of new roller technique. The roller bending force and the positions of serial rollers are set up and regulated by plate shape controlling model, which consists of presetting control model, dynamic control model and plate shape and thickness decoupling model.

Parallel decoupling mechanism with 6 degree of freedom

Abstract: A 4-freedom-parallel decoupling mechanism has 3 same drive units which are orthogonal and connected between the supporting plates of frame and the movable platform, and another drive unit different from the first three in their single-freedom rotation sets. The said drive unit is composed of guide track fixed to supporting plate, slide table equipped to said guide track, driver fixed to guide track and connected to slide table, a planar 2-freedom moving set fixed to another end of slide table, and a single-freedom rotation set connected between said planar 2-freedom moving set and movable platform. Its advantages are simple structure, easy control, unconditional decoupling and high precision.

High-Density, Low-loss MOS Decoupling Capacitors integrated in a GSM Power Amplifier

Abstract: High-density MOS capacitors have been fabricated with ∼ 30 nF/mm2 specific capacitance on highly-doped Si-wafers with arrays of macropores with ∼ 2 μm diameter. Using the Bosch process [1] these pores were dry-etched to depths of ∼ 30 μm or more. The enlarged Si-surface thus obtained serves as a substrate for capacitors fabricated by fully MOS-compatible processing. Wafers were fabricated with a top electrode of poly-Si and Al and ‘ONO’ (i.e. oxide / nitride / oxide) dielectric stacks showing 7–10 MV/cm electrical breakdown field and leakage < 1 nA/mm2 @ 20 V. These wafers were thinned to 380 μm and sawn into dies, representing 40 nF capacitors. Typically low loss factors such as ESR < 50 mΩ and ESL < 20 pH and resonance frequencies of ∼ 0.1 GHz were found for 40 nF capacitor dies. Next, 40 nF dies were mounted by wire bonding on Al2O3 or laminate substrate as supply-line decoupling capacitors in complete GSM power amplifier test modules. RF decoupling and transmission were measured and compared to identical test modules with conventional discrete ceramic capacitors. The MOS capacitors showed very efficient decoupling, resulting in superior signal stability as measured in the 0 – 1 GHz range (less noisy, free from oscillations). The new capacitor is very suitable for integrated decoupling purposes, e.g. supply-line decoupling in RF wireless communication and analog and mixed-signal systems.