Showing papers on "Filter capacitor published in 2001"

Analog characteristics of metal-insulator-metal capacitors using PECVD nitride dielectrics

Abstract: The frequency dependence of PECVD nitride and LPCVD oxide metal-insulator-metal (MIM) capacitors is investigated with special attention for precision analog applications. At measurement frequencies of 1.0 MHz, nitride MIM capacitors show capacitance linearity close to that of oxide MIM capacitors, indicating potential for precision analog circuit applications. Due to dispersion effects, however, nitride MIM capacitors show significant degradation in capacitor linearity as the frequency is reduced, which leads to accuracy limitations for precision analog circuits. Oxide MIM capacitors are essentially independent of frequency.

Integrated emi filter-DC blocking capacitor

Abstract: An integrated electromagnetic interference (EMI) filter capacitor and DC blocking capacitor is provided in a single monolithic casing of ceramic dielectric material. First and second sets of electrode plates are disposed within the monolithic casing to form the DC blocking capacitor, and ground electrode plates are disposed between selected portions of the first and second sets of electrode plates to form the EMI filter. In several of the embodiments, the first and second sets of electrode plates form a plurality of distinct DC blocking capacitors. The ground electrode plates cooperatively form, with the first and second sets of electrode plates, EMI filters for each of the distinct DC blocking capacitors. Discontinuous lead wires may be provided which extend at least partially into the casing, wherein a first segment of the lead wire is conductively coupled to the first set of electrode plates, and a second set of the lead wire is conductively coupled to the second set of electrode plates. Grounded shields also may be co-planarly disposed between adjacent components of the first and second sets of electrode plates to reduce cross-talk therebetween.

Electronic package having embedded capacitors and method of fabrication therefor

Abstract: An electronic package (302, Figure 3) includes one or more capacitors (308) embedded within one or more layers (310) of the package. The embedded capacitors are discrete devices, such as integrated circuit capacitors (Figures 17-18) or ceramic capacitors. During the package build-up process, the capacitors are mounted (410, Figure 4) to a package layer, and a non-conductive layer is applied (412) over the capacitors. When the build-up process is completed, the capacitor's terminals (604, 608, Figure 6) are electrically connected to the top surface of the package. The embedded capacitor structure can be used in an integrated circuit package (1904, Figure 19), an interposer (1906), and/or a printed circuit board (1908).

Pulse power capability of high energy density capacitors based on a new dielectric material

Abstract: A new dielectric composite consisting of a polymer coated onto a high-density metallized Kraft has been developed for application in pulse power capacitors. The polymer coating is custom formulated for high dielectric constant and strength with minimum dielectric losses. The composite can be wound and processed using conventional wound film capacitor manufacturing equipment. This new system has the potential to achieve 2 to 3 J/cm/sup 3/ whole capacitor energy density at voltage levels above 3.0 kV, and can maintain its physical properties to temperatures above 175/spl deg/C. The technical and manufacturing development of the composite material and fabrication into capacitors are summarized in this paper. Energy discharge testing, including capacitance and charge-discharge efficiency at normal and elevated temperatures, as well as DC life testing were performed on capacitors manufactured using this material. TPL (Albuquerque, NM) has developed the material and Aerovox (New Bedford, MA) has used the material to build and test model capacitors. The results of the testing will focus on pulse power applications specifically those found in electromagnetic armor and guns, high power microwave sources and defibrillators.

Optimal design of interleaved synchronous buck converter at high slew-rate load current transients

Abstract: An interleaved synchronous-buck converter for powering future microprocessors is analyzed at high slew-rate load-current transients. Optimal design procedure is suggested based on derived equations for any number of channels. Output filter design example for popular 12-V input, 1.5-V, 50-A regulator is presented to illustrate analysis and compare different number of channels and type of capacitors for this application.

Sensor and sigma-delta converter

Abstract: A sensor for determining at least one parameter with a sigma-delta converter ( 1 ) comprises switched input capacitors and feedback capacitors (Cf 1, Cf 2, Crefc 1, Crefc 2, Creff 1, Creff 2, Crt 1, Crt 2, Cr 1, Cr 2, Ctemp 1, Ctemp 2, Cs 1, Cs 2 ). At least one of the capacitors is designed such that its capacitance depends on the parameter to be determined. In this way, the change of capacitance can be directly determined by means of the sigma-delta converter. Due to a symmetric design of the converter a higher accuracy can be reached.

Hold-up-time extension circuits

Abstract: The stored energy in the energy-storage capacitors of a power supply during the hold-up time is improved by providing two groups of energy storage capacitors, and by connecting one group of capacitors to the input of a hold-up-time extension circuit that has its output connected to the other group of energy-storage capacitors. Each group of energy-storage capacitors may consist of a single capacitor, or a number of capacitors connected in parallel. The hold-up-time extension circuit is designed so that its output is regulated at a voltage that is lower than the minimum regulation voltage of the output-stage dc/dc converter. As a result, the hold-up-time extension circuit is inactive during the normal operation mode. i.e., when the input voltage is present. In fact, during the normal operation mode both groups of capacitors are effectively connected in parallel so that their voltages are equal.

Electrical behavior of decoupling capacitors embedded in multilayered PCBs

Abstract: We describe the modeling of prototype capacitors embedded in multilayered printed circuit boards. We present the design of these devices. We also report measurement and characterization results. The emphasis is on the modeling of via hole connections to the embedded capacitor, not on the technology of buried capacitors. Several designs have been compared with respect to their electrical behavior. In particular, several via hole configurations have been studied, because they are the main cause of parasitic behavior. With these buried capacitors, we obtained a reduction of the parasitic inductance of 80% compared to an equivalent discrete capacitor. This work has been carried out under a European Brite-EuRAM funded project COMPRISE (BE 96-3371). The objective of this project was to develop new materials and manufacturing processes to embed passive components (R, L, and C) within printed wiring structures fabricated from laminate materials. This technology enables the manufacture of space efficient and radio frequency (RF) optimal performing types of modules or board assemblies particularly suited to the market domain of portable and handheld communication and information technology products.

Sensing method and apparatus for resistance memory device

Abstract: An MRAM memory integrated circuit is disclosed. Resistance, and hence logic state, is determined by discharging a first charged capacitor through an unknown cell resistive element to be sensed at a fixed voltage, and a pair of reference capacitors. The rate at which the parallel combination of capacitors discharge is between the discharge rate associated with a binary ‘1’ and ‘0’ value, and thus offers a reference for comparison.

Novel soft-switching DC-DC converter with full ZVS-range and reduced filter requirement. II. Constant-input, variable-output applications

Abstract: For pt.I see ibid., vol.16, no.2, p.184-92 (2001). The performance of the hybrid converter featuring zero-voltage-switching (ZVS) down to no-load and significant reduction in the filter requirement, proposed in Part I of this paper, is analyzed here for constant-input, variable-output applications. For these applications, the main drawback of the hybrid converter, namely the increased transformer rating is eliminated. The advantages of the hybrid configuration like the reduction in filter rating and full-load ZVS with negligible penalty on conduction loss, are retained. An extension of the basic hybrid converter-a combination of two full-bridges using six switches is proposed. This configuration is well suited for applications above a few kilowatts, and results in significant reduction in the ripple current rating of the input filter capacitor. Experimental results obtained from a 1 kW/100 kHz prototype are presented.

High frequency model for power electronics capacitors

Abstract: The study of metallized capacitor behavior at high frequencies points out the presence of series and parallel resonances that could lead to oscillations, perturbations and additional losses in power electronics apparatus. Starting from an already established analytical model of this resonance, we propose a method to elaborate equivalent circuits suiting circuit simulators. These models should help further investigations on high frequency properties of decoupling and snubber capacitors in commutation cells.

High-dielectric constant insulators for feol capacitors

Abstract: Methods of forming front-end-of the line (FEOL) capacitors such as polysilicon-polysilicon capacitors and metal-insulator-silicon capacitors are provided that are capable of incorporating a high-dielectric constant (k of greater than about 8) into the capacitor structure. The inventive methods provide high capacitance/area devices with low series resistance of the top and bottom electrodes for high frequency responses. The inventive methods provide a significant reduction in chip size, especially in analog and mixed-signal applications where large areas of capacitance are used.

Comparative evaluation of modulation methods for a three-phase/switch buck power factor corrector concerning the input capacitor voltage ripple

Abstract: For a three-phase three-switch buck-type PWM rectifier with unity power factor, the RMS value of the input filter capacitor voltage ripple is calculated for different modulation methods. A modulation method being optimal concerning the occurring switching losses and the RMS value of the capacitor voltage ripple is identified and guidelines for the dimensioning of the input filter are derived.

Structure and method for embedding capacitors in z-connected multi-chip modules

Abstract: A chip module element having an array of capacitors, a planar interconnect structure coupled to the array of capacitors, and a multilayer circuit structure coupled to the planar interconnect structure. The planar interconnect structure includes a plurality of conductive elements (e.g., z-connections and conductive posts) electrically communicating the capacitors and the multilayer circuit structure. A plurality of conductive pins is coupled to the multilayer circuit structure. The array of capacitors is capable of being charged by providing an electrical current which passes from the pins, through the multilayer circuit structure, through the conductive elements, and to the capacitors. A method for making a chip module element comprising forming an array of capacitors, electrically testing the capacitors in the array to determine which capacitors are defective and which are acceptable, and storing data of the defective capacitors in an information storage medium. The method further includes forming an interconnect structure on the array of capacitors, wherein the interconnect structure includes a plurality of conductive elements, and wherein the conductive elements are electrically coupled to the acceptable capacitors.

Distributed SPICE circuit model for ceramic capacitors

Abstract: Discrete ceramic capacitors are used to achieve a low power supply impedance in the MHz range. The traditional series RLC circuit model for discrete capacitors is inadequate for low ESR capacitors when mounted on low ESL pads. When combined with other capacitors or power plane models, the simple RLC model does not correctly predict the magnitude or frequency of the anti-resonant peak formed by the parallel components. Discrete capacitors have higher ESR and lower inductance than expected at frequencies above series resonance. A new distributed circuit model is proposed for high Q, low ESR capacitors. The distributed model correlates well with hardware measurements. Both simulated and measured results indicate that anti-resonant peaks are higher in frequency and lower in magnitude than predicted by the traditional series RLC model. Low ESR capacitors do not create the high impedance peak expected from simulation of the traditional series RLC circuit model.

Apparatus and process for the control of electromagnetic fields on the surface of EMI filter capacitors

Abstract: In a feedthrough terminal assembly, a guard electrode plate is disposed within the ceramic casing and adjacent to a surface of an electromagnetic interference (EMI) filter capacitor for reducing electromagnetic field stress on that surface. In a related process, the ground electrode plate is optimized utilizing computer generated electrostatic field modeling. The guard electrode plate may be grounded, either to external capacitor surface metallization or internal capacitor surface metallization. Alternatively, the guard electrode plate may float within the casing in a manner where it is electrically isolated from both the active and ground sets of electrode plates of the EMI filter capacitor. A second guard electrode plate may also be disposed within the casing adjacent to an opposite axial surface of the capacitor casing for reducing electromagnetic field stress on that adjacent surface of the casing.

A new VRM topology for next generation microprocessors

Abstract: Modern computing devices, featuring extremely fast load current transients, impose severe issues to the design of voltage regulation modules (VRM) interfacing the microprocessor power bus with the main board power supply. Using conventional design techniques bulk and expensive high quality output filter capacitors are required to cope with load current slew rates higher than 10 A//spl mu/s. This paper proposes an alternative approach to improve the performance of voltage regulation modules, without requiring impractical output filter capacitors. The proposed approach is based on introducing a very low inductance current path on a voltage regulation module based on a multiphase converter.

Copper MIM structure and process for mixed-signal and Rf capacitors and inductors

Abstract: In many mixed-signal or radio frequency Rf applications, inductors and capacitors are needed at the same time. For a high performance inductor devices, a thick metal layer is needed to increase performance, usually requiring an extra masking process. The present invention describes both a structure and method of fabricating both copper metal-insulator-metal (MIM) capacitors and thick metal inductors, simultaneously, with only one mask, for high frequency mixed-signal or Rf, CMOS applications, in a damascene and dual damascene trench/via process. High performance device structures formed by this invention include: parallel plate capacitor bottom metal (CBM) electrodes and capacitor top metal (CTM) electrodes, metal-insulator-metal (MIM) capacitors, thick inductor metal wiring, interconnects and contact vias.

Wireless communication system

Abstract: A wireless communication system, which is provided with a PLL circuit having a plurality of oscillators and is capable of processing two or more transmit and receive signal different in frequency band from one another according to the switching between the oscillators, has a reset means which resets a voltage applied to each of filter capacitors lying within the PLL circuit to a predetermined voltage when the switching between the oscillators is performed.

A 1.8-V MOSFET-only /spl Sigma//spl Delta/ modulator using substrate biased depletion-mode MOS capacitors in series compensation

Abstract: A low-voltage high-linearity MOSFET-only /spl Sigma//spl Delta/ modulator for speech band applications is presented. The modulator uses substrate biased MOSFETs in the depletion region as capacitors, linearized by a series compensation technique. A second-order fully differential single-loop architecture has been realized in a conventional 0.25-/spl mu/m digital n-well CMOS process without extra layers for capacitors. An SNDR of 72 dB and an SNR of 77 dB is obtained with 8-kHz signal bandwidth at an oversampling ratio of 64. The circuit consumes about 1 mW from a single 1.8-V power supply and occupies a core area of 0.08 mm/sup 2/.

Current measurement circuit

Abstract: The present invention is connected across a sense resistor which carries a current of interest. A first pair of cross-coupled switches are connected between the sense resistor and respective input capacitors, and a second pair of cross-coupled switches are connected between the input capacitors and the inputs of an amplifier having differential inputs and outputs. Feedback capacitors are connected between each of the amplifier's outputs and inputs. A control circuit operates the cross-coupled switches in accordance with a switching cycle, during which the connections between the sense resistor and the input capacitors are interchanged, after which the connections between the input capacitors and the differential amplifier are interchanged. When so arranged, the sensed voltage is sampled on the input capacitors and transferred to the feedback capacitors to produce a differential output voltage V out from the differential amplifier which is proportional to the current of interest.

Considerations for the application of series capacitors to radial power distribution circuits

Abstract: This paper summarizes many of the considerations in the application of series capacitors on radial distribution circuits. The effects of series capacitors on receiving end voltages are illustrated via phasor diagrams and power-voltage characteristics. The unique voltage profile of the compensated distribution circuit is presented. Discussed are the various types of distribution circuit problems that series capacitors typically used to solve. Application guidelines are presented to help minimize oscillatory interactions with transformers and motors. The various protection schemes used in practical series capacitor banks are discussed. The information required to specify distribution series capacitor banks is outlined.

High current filter feed-through capacitor

Abstract: An improved monolithic multilayer ceramic filter capacitor for use with implanted medical devices such as pacemakers and defibrillators The capacitor includes a parallel stack of positive electrode plates that have sufficient current carrying capability to be directly connected in series with a lead wire from an implanted medical device Therefore, the capacitor may be used for both filtering and pulsed energy transmission High current capability is achieved through the use of interleaved electrode plates where the positive electrodes are connected in parallel, and where at least one of the positive electrodes is of sufficiently high conductor density to carry a majority of the current transmitted by the implantable medical device lead

MEMS-based series and shunt variable capacitors for microwave and millimeter-wave frequencies

Abstract: This article describes design and modeling of MEMS-based variable capacitors with rf performance acceptable for microwave and millimeter-wave applications. Appropriately designed thermal actuators are used to move the MEMS capacitor plate vertically to change the air gap between the MEMS plate and the signal line of a coplanar waveguide (CPW). Both series- and shunt-mounted capacitors have been demonstrated. Effect of actuator design on rf performance is investigated by electromagnetic simulation. Experimental results show an air gap change resulting in a capacitance variation with a ratio of 2.7:1. For the shunt-mounted capacitor, the capacitance showed no self-resonance and the equivalent resistance is less than 0.5 Ω in the frequency range up to 40 GHz. The MEMS-based variable capacitors are described with an emphasis on rf design and characterization. In particular, the effects of actuator design on rf performance are discussed in details.

Package capacitors impact on microprocessor maximum operating frequency

Abstract: This paper discusses the behavior of microprocessor (CPU) maximum operating frequency (FMAX) under various conditions. In specific, the impact of voltage and temperature on the CPU FMAX for a gate delay dominated design vs. an RC-interconnect delay dominated design are described. As voltage tolerance is reduced through proper design placement of package capacitors, and using the optimal amount of capacitance and resistance (ESR) for the package capacitors, the CPU FMAX increases.

RFI filter for a frequency converter

Abstract: The invention relates to an RFI filter used for avoidance of mains retro-action in the form of radio noise. RFI filters are connected to frequency converters in order to reduce radio noise transmitted via conductors. These filters comprise large noise-decoupling capacitors which are connected to earth, and during start up of the frequency converter the capacitors cause leakage currents to earth. This gives rise to problems in those circumstances, where a circuit breaker is connected to a frequency converter and an RFI filter, because the leakage current is higher than the trigger current for the circuit breaker. The solution to this problem is to place a resistor in series with the noise-decoupling capacitor and parallel with the resistor to place a switch, which can be opened or closed with a control signal from a controller. The invention also concerns a method for activation of an RFI filter.

Voltage drop DC-DC converter

Abstract: A voltage drop DC-DC converter includes a switch circuit including a plurality of switches for alternately connecting a first and second capacitors in series and in parallel in response to an output signal of an oscillator circuit oscillating at a constant frequency. An efficient voltage dropping conversion is possible by deriving a voltage divided by the first and second capacitors when the first and second capacitors are connected in series and deriving terminal voltages of the first and second capacitors when the first and second capacitors are connected in parallel. When the derived voltage is increased beyond an aimed reference output voltage, the oscillation of the oscillator circuit is stopped.

An ultra-compact Marx-type high-voltage generator

Abstract: This paper discusses the design of an ultra-compact, Marx-type, high-voltage generator. This system incorporates high-performance components that are closely coupled and integrated into an extremely compact assembly. Low profile, custom ceramic capacitors with coplanar extended electrodes provide primary energy storage. Low-inductance, spark-gap switches incorporate miniature gas cavities imbedded within the central region of the annular shaped capacitors, with very thin dielectric sections separating the energy storage capacitors. Carefully shaped electrodes and insulator surfaces are used throughout to minimize field enhancements, reduce fields at triple-point regions, and enable operation at stress levels closer to the intrinsic breakdown limits of the dielectric materials. Specially shaped resistors and inductors are used for charging and isolation during operation. Forward-coupling ceramic capacitors are connected across successive switch-capacitor-switch stages to assist in switching. Pressurized SF/sub 6/ gas is used for electrical insulation in the spark-gap switches and throughout the unit. The pressure housing is constructed entirely of dielectric materials, with segments that interlock with the low-profile switch bodies to provide an integrated support structure for all of the components. This ultra-compact Marx generator employs a modular design that can be sized as needed for a particular application. Units have been assembled with 4, 10, and 30 stages and operated at levels up to 100 kV per stage.

The feedforward method of controlling three-level diode clamped converters with small DC-link capacitors

Abstract: This paper introduces a control method, which enables the distortion-free operation of a three-level converter in the presence of significant neutral point voltage ripple Application of this control method allows a trade-off between the voltage capacity of the switching devices and the size of the DC-link capacitors