Showing papers on "RLC circuit published in 2002"

Automatic phase-shift method for islanding detection of grid-connected photovoltaic inverters

Abstract: The traditional frequency-shift methods for islanding detection of grid connected PV inverters (the active frequency-drift method and the slip mode frequency-shift method) become ineffective under certain paralleled RLC loads. The automatic phase-shift method is proposed in this paper to alleviate this problem. The method is based on the phase shift of the sinusoidal inverter output current. When the utility malfunctions, the phase-shift algorithm keeps the frequency of the inverter terminal voltage deviating until the protection circuit is triggered. Simulation and experiments are performed for verification.

Frequency-independent equivalent circuit model for on-chip spiral inductors

Abstract: A wide-band, physical and scalable 2-/spl Pi/ equivalent circuit model for on-chip spiral inductors is developed. Using frequency-independent RLC elements, it accurately captures R(f) and L(f) characteristics beyond the self-resonant frequency. This new model is fully compatible with both AC and transient analysis. Verification with measurement data demonstrates excellent scalability for a wide range of inductor configurations.

Analysis of on-chip inductance effects for distributed RLC interconnects

Abstract: This paper introduces an accurate analysis of on-chip inductance effects for distributed RLC interconnects that takes the effect of both the series resistance and the output parasitic capacitance of the driver into account. Using rigorous first principle calculations, accurate expressions for the transfer function of these lines and their time-domain response have been presented for the first time. Using these, a new and computationally efficient performance optimization techniques for distributed RLC interconnects has been introduced. The new optimization technique has been employed to analyze the impact of line inductance on the circuit behavior and to illustrate the implications of technology scaling on wire inductance. It is shown that reduction in driver output resistance and input capacitance with scaling can make deep submicron designs increasingly susceptible to inductance effects if global interconnects are not scaled. For scaled global interconnects with increasing line resistance per unit length, as prescribed by the International Technology Roadmap for Semiconductors, the effect of inductance on interconnect performance actually diminishes.

Design and implementation of an inverter output LC filter used for dv/dt reduction

Abstract: This paper presents the design and analysis of a LC output filter for use with IGBT-based motor drive inverters. The LC filter is used to limit the rate of rise of the inverter output voltage and reduce common mode noise to the motor. In typical applications where dv/dt is limited to 100-500 V//spl mu/s, the resonant frequency of the filter is above the switching frequency. A diode bridge must therefore be used to clamp the resonant voltage. Resistors are also used to help dissipate the energy stored in the resonant circuit. Crucial to the design of the filter is the handling of the additional losses in the filter. The paper describes the design considerations for such a filter for use in a 460 V induction motor drive. The losses in the circuit are estimated to show the limitations of the filter. Experimental results illustrate the control of dv/dt at the inverter terminals, and the reduced peak voltage at the motor end of a long cable.

Comparison of low-frequency piezoelectric switching shunt techniques for structural damping

Abstract: In this paper, the performances of two novel low-frequency piezoelectric switching shunt techniques for structural damping are compared to the traditional passive tuned resonant shunt circuit technique. The first novel technique, state switching, is a semi-active variable stiffness technique in which bonded piezoelectric elements are switched from the short circuit to open circuit states. This technique changes the stiffness of the structure for two quarters of its vibration period, thus dissipating energy. The second novel technique, pulse switching, is a semi-active continuous switching technique in which a resistor/inductor shunt circuit is periodically connected to the bonded piezoelectric elements. This technique applies charges to the piezoelectric elements in a manner similar to the direct velocity feedback and bang-bang time optimal control techniques. A brief description of each of the damping techniques is given. Numerical simulations of the switching techniques are shown and compared to the resonant shunt damping technique. Finally, preliminary experimental results are presented for the resonant shunt, state switching, and pulse switching techniques on a simply supported beam.

Wireless, passive, resonant-circuit, inductively coupled, inductive strain sensor

Abstract: This paper presents a non-contact, wireless, passive, inductively coupled strain sensor. The sensor itself is a parallel-connected LC tank circuit. Small geometric changes in a stressed solenoidal inductor were predicted to affect its inductance and as a consequence the resonant frequency of the LC circuit. Using a gate dip meter as a sensitive detector, this was experimentally confirmed. There was found to be a consistent relationship between relative strain with shifted resonant frequency independent of whether the sensor was embedded or not.

Power Shaping: A New Paradigm for Stabilization of Nonlinear RLC Circuits

Abstract: It is well known that arbitrary interconnections of passive (possibly nonlinear) resistors, inductors, and capacitors define passive systems, with port variables the external source voltages and currents, and storage function the total stored energy. In this note, we prove that for a class of RLC circuits with convex energy function and weak electromagnetic coupling it is possible to "add a differentiation" to the port terminals preserving passivity - with a new storage function that is directly related to the circuit power. The result is of interest in circuits theory, but also has applications in control as it suggests the paradigm of power shaping stabilization as an alternative to the well-known method of energy shaping. We show in this note that, in contrast with energy shaping designs, power shaping is not restricted to systems without pervasive dissipation and naturally allows to add "derivative" actions in the control. These important features, that stymie the applicability of energy shaping control, make power shaping very practically appealing. To establish our results we exploit the geometric property that voltages and currents in RLC circuits live in orthogonal spaces, i.e., Tellegen's theorem, and heavily rely on the seminal paper of Brayton and Moser in 1964.

Simultaneous switching noise in on-chip CMOS power distribution networks

Abstract: Simultaneous switching noise (SSN) has become an important issue in the design of the internal on-chip power distribution networks in current very large scale integration/ultra large scale integration (VLSI/ULSI) circuits. An inductive model is used to characterize the power supply rails when a transient current is generated by simultaneously switching the on-chip registers and logic gates in a synchronous CMOS VLSI/ULSI circuit. An analytical expression characterizing the SSN voltage is presented here based on a lumped inductive-resistive-capacitive RLC model. The peak value of the SSN voltage based on this analytical expression is within 10% as compared to SPICE simulations. Design constraints at both the circuit and layout levels are also discussed based on minimizing the effects of the peak value of the SSN voltage.

A novel electrode power profiler for dimmable ballasts using DC link voltage and switching frequency controls

Abstract: A novel electrode power profiler for dimmable ballasts using a series-resonant parallel-loaded inverter is presented. Dimming of fluorescent lamps and control of the electrode power are achieved by simultaneously adjusting the DC link voltage and the switching frequency of the inverter. The current gradient along the electrode, which is due to the distributed lamp current property on the electrode, is deliberated in formulating the power and voltage models of the electrode. As the electrode heating relies on two near-orthogonal current components including the lamp current and the resonant tank circuit current, a simple feedback control is developed to derive the electrode power. Reduction of the electrode power (due to the decrease in the lamp current) during dimming is compensated by increasing the switching frequency of the inverter, in order to increase the resonant tank circuit current. Experimental results of a T8 36 W prototype are verified with theoretical predictions.

Design of defected ground structures for harmonic control of active microstrip antenna

Abstract: Photonic bandgap (PBG) structures are usually periodic structures in which propagation of a certain band of frequencies is prohibited. PBG structures for microwave frequencies are applied in planar circuits such as microstrip line and CPW (coplanar waveguide). In this case, they are more frequently termed defected ground structures (DGS). Most of the research performed on DGS has been based on the equivalent circuit consisting of lumped elements, L and C, extracted from EM simulations (see D. Ahn et al., IEEE MTT, vol.49, 2001). In addition, we also consider radiation effects by including resistance, R, in the equivalent circuit. The general 1D periodic structures with N unit cells are analyzed using an ABCD matrix formulation. The effects of the RLC elements of the unit cell, the spacing between the unit cells, and the cell number, N, are investigated in detail. For a design example, a simple 1D DGS with N=2 is designed for harmonic control through a modeling using transmission line theory. This 1D DGS with N=2 is much simpler than the one proposed by Y. Horii and M. Tsutsmi (see IEEE MGWL, vol.9, no.1. p.1895-8, 1999). The proposed approach enables us to design the required DGS quite easily and quickly.

Computation of design values for Class E amplifiers without using waveform equations

Abstract: This paper presents a novel design procedure for Class E amplifiers without using waveform equations. By the proposed design procedure, Class E amplifiers can be designed regardless of the Q factor of resonant circuit, existence of the switch on resistor, and so on. The proposed design procedure requires only circuit equations and design specifications. All design procedures reported until now require deriving waveform equations which requires a lot of work. The benefits of the proposed design procedure is that it is to deriving waveform equations is no longer necessary. When the circuit equations are obtained, the other procedures for computation of design values are carried out with aid of computer. Therefore, we can design Class E amplifier more easily than the conventional design procedure. The authors design Class E amplifiers by using the proposed design procedures and carry out the circuit experiments, and find that the experimental results agree with calculation results, and show the validity of the proposed design procedure.

Pressure sensor, pressure measuring apparatus, and pressure measurement system using them

Abstract: PROBLEM TO BE SOLVED: To provide a pressure measurement system using a pressure detection sensor that has a simple configuration and is inexpensive and a pressure measuring apparatus. SOLUTION: The pressure measurement system 1 comprises the pressure sensors 50a-50d and the pressure measuring apparatus 10. The pressure sensors 50a-50d are composed as a radio tag having a resonance circuit, where a resonance frequency changes depending on pressure. The pressure measuring apparatus 10 detects the resonance frequency of the resonance circuit and specifies the pressure of the radio tag, based on the detected resonance frequency, by transmitting or receiving radio waves to and from the pressure sensors 50a-50d. COPYRIGHT: (C)2004,JPO

Analysis of high-frequency induction cooker with variable frequency power control

Abstract: This paper presents an analysis of a high frequency induction cooker, using a half-bridge series resonant inverter. The circuit operation is first analyzed, using the Thevenin short-open circuit method, in order to develop an equivalent circuit of simple RLC series connection. Then, by this simplified circuit, voltage and current equations with their spectra can be easily obtained and consequently leading to the calculation of various electrical quantities, which are also verified by experiment, using a prototype cooker of 2 kW 30 kHz with variable power and variable frequency. This cooker also shows that at the same power level of 1.5 kW, its boiling performance is faster than that of the conventional one, 5 and 10 minutes, respectively.

Adaptive piezoelectric shunt damping

Abstract: Piezoelectric shunt damping systems reduce structural vibration by shunting an attached piezoelectric transducer with an electrical impedance. Current impedance designs result in a coupled electrical resonance at the target modal frequencies. In practical situations, variation in structural load or environmental conditions can result in significant changes in the structural resonance frequencies. This variation can severely reduce shunt damping performance as the electrical impedance remains tuned to the nominal resonance frequencies. This paper introduces a method for online adaption of the shunting impedance. A reconstructed estimate of the RMS\ strain is minimized by varying the component values of a synthetic shunt damping circuit. The presented techniques are applied in real time, to tune the component values of a randomly excited beam.© (2002) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.

Method and apparatus providing a dual mode VCO for an adaptive receiver

Abstract: An RF VCO (260A) forms, in the preferred embodiment, a part of a dual mode mobile station (100). Also disclosed is a method for operating the VCO. The VCO is operated in a first frequency band using a first inductance (300A) that forms part of a first resonant circuit (parallel resonance), and the VCO is switched for operation to a second frequency band by the closing a switch (M5) that causes a second resonant circuit (serial resonance) to be inductively coupled to the first resonant circuit. The second resonant circuit includes a second inductance (300B), and preferably includes at least one frequency tunable component, such as a varactor (VR3, VR4), for adjusting the resonant frequency of the second resonant circuit. The second inductance is center tapped, and the switch, such as a MOS transistor, is coupled in series between two ends of the center tapped inductance. The first frequency band may include 3.6 GHz (a double frequency GSM band) and the second frequency band may include 4.3 GHz (a double frequency WCDMA band). Additional operational bands can be also be used. In the preferred embodiment the first inductance forms part of a transformer primary fabricated in an integrated circuit, and the second inductance forms part of the transformer secondary that is fabricated in the integrated circuit so as to underlie the first inductance. A signal detector (D1, D2) may be provided that is responsive to a signal induced in the transformer secondary, and the signal detector has an output coupled to a closed loop control circuit (310) for controlling a magnitude of a signal output from the VCO. A further input to the closed loop control circuit may be a signal that is indicative of communication channel conditions, and the current consumption of the VCO circuit is maintained at a level that is adequate to ensure operation with the communication channel conditions. A passive buffering circuit (320) is provided for coupling an output of the VCO circuit to a further circuit, such as a mixer, thereby reducing the total VCO current considerably.

Diplexer, and high-frequency switch and antenna duplexer using the same

Abstract: A diplexer capable of passing signals of a high frequency band without being attenuated over a wide frequency band, and a high-frequency switch using the diplexer are provided The diplexer includes a low-pass filter 82 having a parallel resonant circuit formed by a first capacitor C 1 and a first inductor L 1 and a serial resonant circuit formed by a second capacitor C 2 and a second inductor L 2 With this structure, two attenuation poles are provided in the low-pass filter 82 Thus, a passband of a high-pass filter 83 can be widened

A new ZVCS resonant push-pull DC/DC converter topology

Abstract: A new ZVCS resonant DC/DC converter is presented in which the resonant circuit is located at the secondary side of the transformer and using the secondary leakage inductance as the resonant inductor. The proposed converter topology is suitable for unregulated low-voltage to high-voltage power conversion, as in battery-powered systems. The MOSFET primary switches and the output rectifiers turn-on and turn-off operate under zero-voltage and zero-current switching conditions. The measured efficiency is more than 94.5% from 20% loaded to full loaded.

Electromagnetic induction heating cooker

Abstract: PROBLEM TO BE SOLVED: To solve the problem that the power consumed in a pan can not be accurately controlled in performing constant input power control of a conventional technique since loss values of an inverter circuit and a controlling circuit are contained in input power. SOLUTION: In this electromagnetic induction heating cooker controlling an output power frequency of the inverter circuit according to a value of comparison operation of an induction heating coil forming a series resonant circuit with a resonant capacitor, the inverter circuit supplying a high frequency current to the induction heating coil, an input power operation circuit calculating the input power of the inverter circuit, and a power-control differential amplification circuit performing a comparison operation of the input power and a power set value, an output power operation circuit calculating the output power of the inverter circuit with the phase difference generated between voltage generated at ends of the induction heating coil, the output current of the inverter circuit, the output voltage of the inverter circuit and the output currents is replaced with the input power operation circuit, and the output power frequency of the inverter circuit is controlled according to the value obtained by the comparison operation of the output power and the power set value. COPYRIGHT: (C)2005,JPO&NCIPI

Effective on-chip inductance modeling for multiple signal lines and application to repeater insertion

Abstract: /sup A/ new approach to handle inductance effects for multiple signal lines is presented. The worst-case switching pattern is first identified. Then a numerical approach is used to model the effective loop inductance (L/sub eff/) for multiple lines. Based on a look-up table for L/sub eff/, an equivalent single line model can be generated to decouple a specific signal line from the others to perform static timing analysis. Compared to the use of full RLC netlists for multiple lines, this approach greatly improves the computational efficiency and maintains accuracy for timing and signal integrity analysis. We apply these models to repeater insertion in critical paths and find that, for a single line, the RLC model minimizes delay with fewer number of repeaters than RC model. However, for multiple lines, we find that same number of repeaters is inserted for optimal delay according to both the RC and RLC models.

Radial mode piezoelectric transformer design for fluorescent lamp ballast applications

Abstract: In a ballast circuit, the piezoelectric transformer (PT) is used to replace the conventional inductor-capacitor resonant tank saving valuable space and cost. During circuit operation, a very high voltage is required to initially ignite the lamp while during sustained operation the voltage requirements are significantly reduced. With ballast in mind, a design process has been developed to optimize a radial mode piezoelectric transformer or Transoner/sup /spl reg// to fit a specific application while simultaneously providing highly efficient performance and the capability to provide ZVS to the switches. The design procedure was verified by a custom-designed PT operating in a 32-watt ballast.

Device and method for contactless transmission of power or data

Abstract: A device and a method for contactless transmission of data or power include an impedance which is connected into an LC resonant circuit only in a phasewise manner, in order to match a resonant frequency of the resonant circuit to an excitation frequency. This is realized by measuring a difference between the resonant frequency and the excitation frequency and connecting the impedance into the resonant circuit as a function thereof in a manner controlled by a charging current. In this case the charging current is phase-gating-controlled, and consequently only an effective component of the impedance is connected into the resonant circuit.

Generalized traveling-wave-based waveform approximation technique for the efficient signal integrity verification of multicoupled transmission line system

Abstract: As very large scale integration (VLSI) circuit speed rapidly increases, the inductive effects of interconnect lines strongly impact the signal integrity of a circuit. Since these inductive effects make the signal integrity problems much more serious as well as intricate, they become one of the critical issues in today's high-speed/high-density VLSI circuit design. In this paper, a generalized traveling-wave-based waveform approximation (TWA) technique is presented which can be accurately as well as efficiently employed for the signal integrity verification of the inductively dominated (moderate Q) multicoupled RLC transmission line system. The technique is composed of three steps. First, the signals in the multicoupled (n-coupled) transmission line system are decoupled into n-isolated eigen-modes (i.e., basis vectors). Next, the slow-transient low-frequency characteristics of the system response are determined, approximately, in the frequency-domain by using the dominant poles of the basis vectors. Finally, the fast-transient high-frequency characteristics of the system response are calculated in the time domain by using the traveling wave characteristics of the basis vectors. It is shown that the time-domain responses of the multicoupled RLC transmission line system can be accurately as well as efficiently modeled with the generalized TWA technique. Then, in inductance-dominant multicoupled interconnect networks, switching-dependent signal integrity, i.e., signal delay, crosstalk, ringing, and glitches are investigated extensively with the proposed technique.

A traveling-wave-based waveform approximation technique for the timing verification of single transmission lines

Abstract: Today's high-speed very large scale integration interconnects are becoming inductively dominated (moderate Q) resistance-inductance-capacitance (RLC) transmission lines. The time-domain system responses of RLC interconnect lines driving load capacitances cannot be accurately represented by using a finite number of poles with exception for a particular case of RC-time-constant-dominant (low Q) RLC systems. In this paper, a new traveling-wave-based waveform approximation technique is presented. The method suggests that a steady-state traveling wave is approximately determined by a three-pole approximation technique. Then the time-domain response of the system can be accurately determined by using the traveling waves that are modeled by multiple reflections. The signal delay models of the RLC interconnect lines are derived as a closed form. The technique is verified by varying the source resistance, load impedance, and transmission line circuit model parameters of several RLC lines. The results show excellent agreement with HSPICE simulation results. That is, approximately 5% error in a 50% delay calculation can be achieved.

DTT: direct truncation of the transfer function - an alternative to moment matching for tree structured interconnect

Abstract: A method is introduced to evaluate time domain signals within RLC trees with arbitrary accuracy in response to any input signal. This method depends on finding a low frequency reduced-order transfer function by direct truncation of the exact transfer function at different nodes of an RLC tree. The method is numerically accurate for any order of approximation, which permits approximations to be determined with a large number of poles appropriate for approximating RLC trees with underdamped responses. The method is computationally efficient with a complexity linearly proportional to the number of branches in an RLC tree. A common set of poles is determined that characterizes the responses at all of the nodes of an RLC tree which further enhances the computational efficiency. Stability is guaranteed by the DTT method for low-order approximations with less than five poles. Such low-order approximations are useful for evaluating monotone responses exhibited by RC circuits.

Window-Based Susceptance Models for Large-Scale RLC Circuit Analyses

Abstract: Due to the increasing operating frequencies and the manner in which the corresponding integrated circuits and systems must be designed, the extraction, modeling and simulation of the magnetic couplings for final design verification can be a daunting task. In general, when modeling inductance and the associated return paths, one must consider the on-chip conductors as well as the system packaging. This can result in an RLC circuit size that is impractical for traditional simulators. In this paper we demonstrate a localized, window-based extraction and simulation methodology that employs the recently proposed susceptance (the inverse of inductance matrix) concept. We provide a qualitative explanation for the efficacy of this approach, and demonstrate how it facilitates pre-manufacturing simulations that would otherwise be intractable. A critical aspect of this simulation efficiency is owed to a susceptance-based circuit formation that we prove to be symmetric positive definite. This property, along with the sparsity of the susceptance matrix, enables the use of some advanced sparse matrix solvers. lye demonstrate this extraction and simulation methodology on some industrial examples.

AC-type plasma display panel having energy recovery unit in sustain driver

Abstract: Disclosed is an apparatus of a sustain driver in an AC-type plasma display panel having an energy recovery unit, comprising: a first drive unit for driving one electrode of a panel capacitor to a sustain voltage or a ground voltage; a second drive unit for driving another electrode of the panel capacitor to a sustain voltage or a ground voltage; and a common energy recovery unit. The common energy recovery unit includes: an inductor connected to the one electrode of the panel capacitor and form a L-C resonance circuit with the panel capacitor; a first and second external capacitors connected in series between the power source of the sustain voltage and the ground; and a switch unit for selectively switching the L-C resonance circuit and the first and second external capacitors during the charge and discharge operation of the panel capacitor.

Series-parallel resonant UPS with capacitive output DC bus filter for powering HFC networks

Abstract: This paper presents a single high-frequency transformer full isolated uninterruptible power supply based on series-parallel resonant converters for powering hybrid fiber-coaxial networks. The proposed UPS provides galvanic isolation for the load and the battery, and operates with high input power factor while producing a trapezoidal output voltage waveform either at 60 Hz or at 1 Hz. Small size and light weight are achieved without penalizing the overall efficiency by operating at high frequency and by ensuring zero voltage switching (ZVS) under the different operating conditions. In addition, it is demonstrated that by using a capacitive output DC bus filter it is possible to reduce the current stresses during the backup mode by the appropriate selection of the transformer turns ratio. A design procedure for the selection of the key resonant circuit parameters is developed and exemplified. Experimental results obtained from a laboratory prototype demonstrate the overall performance of the system.

Low-loss tunable ferro-electric device and method of characterization

Abstract: A tunable ferroelectric component and a narrowband resonant circuit for measuring the loss of the ferroelectric component. The ferroelectric component may be a capacitor integrated in the resonant circuit. The testing method eliminates other sources of loss to isolate the loss due to the ferroelectric material and to demonstrate that this loss is low.

An Interconnect-Aware Methodology for Analog and Mixed Signal Design, Based on High Bandwidth (Over 40 Ghz) On-Chip Transmission Line Approach

Abstract: This paper presents an on-chip, interconnect-aware methodology for high-speed analog and mixed signal (AMS) design which enables early incorporation of on-chip transmission line (T-line) components into AMS design flow. The proposed solution is based on a set of parameterized T-line structures, which include single and two coupled microstrip lines with optional side shielding, accompanied by compact true transient models. The models account for frequency dependent skin and proximity effects, while maintaining passivity requirements due to their pure RLC nature. The signal bandwidth supported by the models covers a range from DC to 100 GHz. The models are currently verified in terms of S-parameter data against hardware (up to 40 GHz) and against EM solver (up to 100 GHz). This methodology has already been used for several designs implemented in SiGe (silicon-germanium) BiCMOS technology.

High-frequency oscillation type proximity sensor

Abstract: A high-frequency oscillation proximity sensor with an improved detection sensitivity uses, as a detection coil 11 , a two-thread coil formed of substantively two coil conductors joined together at their first ends to form a joint connection end and twisted together, one of the two coil conductors being used as a resonance circuit coil L 1 and the other as a copper resistance compensation coil L 2 , and comprises a drive circuit 12 for supplying a drive current to the joint connection end of the two-thread coil to thereby drive the detection coil to oscillate, a buffer 13 for taking out an oscillating output voltage generated at the joint connection end of the two-thread coil, and a phase shift circuit 15 for turning the phase of the oscillating output voltage taken out by the buffer by a predetermined angle and feeding it back to the copper resistance compensation coil to thereby negate the copper resistance of the two-thread coil. The drive circuit comprises a nonlinear amplifier 21 for changing the amplitude of the oscillating voltage generated at the two-thread coil in multiple stages to thereby impart a soft oscillation characteristic to a high-frequency oscillation circuit comprising the nonlinear amplifier and the two-thread coil.