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Showing papers on "Inductor published in 2003"


Patent
Willem G. Odendaal1, Yushan Li1
10 Jun 2003
TL;DR: A planar resonator and method of manufacture provides contactless power transfer using at least two electrically isolated axis aligned conductive across the transfer interface in a coupled inductor or transformer configuration.
Abstract: A planar resonator and method of manufacture provides contactless power transfer using at least two electrically isolated axis aligned conductive across the transfer interface in a coupled inductor or transformer configuration. Signal or power transfer is then accomplished by coupling of magnetic flux. The coupling of electric flux is also accomplished across a same interface and driven with the same conductive spiral-wound conductors. An interface of energy transfer(IOET) has a first spiral-shaped conductor arranged on the top surface of said IOET; a second spiral-shaped conductor arranged on the bottom surface of said IOET, has a vertical axis aligned with the first spiral-shaped conductor. The IOET and the first and second spiral-shaped conductors have a predetermined self-resonant frequency. The planar power resonator stores electric energy in the IOET, and at predetermined frequencies, the arrangement of the first and second spiral-shaped conductors and the IOET permits transfers of magnetic flux and electrical energy between the first and second spirals across the IOET. The resonator facilitates contactless battery charging in devices such as cellphones and wearable electronics where the resonator can be woven into fabric or attached to a person's clothes.

489 citations


Journal ArticleDOI
TL;DR: In this article, a wideband physical and scalable 2-spl Pi/ equivalent circuit model for on-chip spiral inductors is developed based on physical derivation and circuit theory, closed-form formulas are generated to calculate the RLC circuit elements directly from the inductor layout.
Abstract: A wide-band physical and scalable 2-/spl Pi/ equivalent circuit model for on-chip spiral inductors is developed. Based on physical derivation and circuit theory, closed-form formulas are generated to calculate the RLC circuit elements directly from the inductor layout. The 2-/spl Pi/ model accurately captures R(f) and L(f) characteristics beyond the self-resonant frequency. Using frequency-independent RLC elements, this new model is fully compatible with both ac and transient analysis. Verification with measurement data from a SiGe process demonstrates accurate performance prediction and excellent scalability for a wide range of inductor configurations.

341 citations


Journal ArticleDOI
TL;DR: In this article, a review of design principles for implementation of a spiral inductor in a silicon integrated circuit fabrication process summarizes prior art in this field, and a fast and physics-based inductor model is exploited to put the results contributed by many different groups in various technologies and achieved over the past eight years into perspective.
Abstract: This review of design principles for implementation of a spiral inductor in a silicon integrated circuit fabrication process summarizes prior art in this field. In addition, a fast and physics-based inductor model is exploited to put the results contributed by many different groups in various technologies and achieved over the past eight years into perspective. Inductors are compared not only by their maximum quality factors (Q/sub max/), but also by taking the frequency at Q/sub max/, the inductance value (L), the self-resonance frequency (f/sub SR/), and the coil area into account. It is further explained that the spiral coil structure on a lossy silicon substrate can operate in three different modes, depending at first order on the silicon doping concentration. Ranging from high to low substrate resistivity, inductor-mode, resonator-mode, and eddy-current regimes are defined by characteristic changes of Q/sub max/, L, and f/sub SR/. The advantages and disadvantages of patterned or blanket resistive ground shields between the inductor coil and substrate and the effect of a substrate contact on the inductor are also addressed in this paper. Exploring optimum inductor designs under various constraints leverages the speed of the model. Finally, in view of the continuously increasing operating frequencies in advancing to new generations of RF systems, the range of feasible inductance values for given quality factors are predicted on the basis of optimum technological features.

320 citations


Patent
02 Jun 2003
TL;DR: A linear metamaterial comprises a transmission line, having a linear dimension, and is loaded with capacitors, and shunted with an inductor such that for an electromagnetic wave having a wavelength greater than the linear dimension and traveling along the axis of the transmission line is simultaneously negative as mentioned in this paper.
Abstract: A linear metamaterial comprises a transmission line, having a linear dimension, and is loaded with capacitors, and shunted with an inductor such that for an electromagnetic wave, having a wavelength greater than the linear dimension and traveling along the axis of the transmission line, the effective permeability and permittivity of the metamaterial are simultaneously negative. Applications for the metameterial are also disclosed.

232 citations


Journal ArticleDOI
TL;DR: A full-bridge converter which employs a coupled inductor to achieve zero-voltage switching of the primary switches in the entire line and load range is described.
Abstract: A full-bridge converter which employs a coupled inductor to achieve zero-voltage switching of the primary switches in the entire line and load range is described. Because the coupled inductor does not appear as a series inductance in the load current path, it does not cause a loss of duty cycle or severe voltage ringing across the output rectifier. The operation and performance of the proposed converter is verified on a 670 W prototype.

223 citations


Patent
29 Apr 2003
TL;DR: In this article, an inductive power line data coupler (10) is presented, which includes a magnetic core having a high magnetic permeability at a data communication frequency and being configured to allow a power line (100) to serve as a primary winding, a data signaling circuit that provides a secondary winding (115) through the magnetic core (105) for coupling a data signal between the power line and a communication device (130), and a choke coil (135) coupled to the data signalling circuit for creating a flux-canceling power frequency current opposite in direction and
Abstract: There is provided an inductive power line data coupler (10). The coupler (10) includes (a) a magnetic core (105) having a high magnetic permeability at a data communication frequency and being configured to allow a power line (100) to serve as a primary winding, (b) a data signaling circuit that provides a secondary winding (115) through the magnetic core (105) for coupling a data signal between the power line (100) and a communication device (130), and (c) a choke coil (135) coupled to the data signaling circuit for creating a flux-canceling power frequency current opposite in direction and comparable in magnitude to a power frequency current. The coupler (10) may also include a circuit for sensing a level of current in the power line (100).

183 citations


Journal ArticleDOI
TL;DR: In this paper, a method of canceling the common-mode EMI by using a compensating transformer winding and a capacitor was proposed, which is much simpler and requires no additional transistors and gate-drive circuitry.
Abstract: It is well known that common-mode (CM) conducted electromagnetic interference (EMI) is caused by the common-mode current flowing through the parasitic capacitance of transistors, diodes, and transformers to ground in the power circuit. Because of the potential for interference with other systems it is necessary to attenuate this noise. Ordinarily this is accomplished by using a magnetic choke across the input power lines, resulting in penalties to the overall size and cost of the completed system. In order to lessen the requirement for this magnetic choke, there has been a desire to introduce noise cancellation techniques to the area of EMI. This text introduces a method of canceling the common-mode EMI by using a compensating transformer winding and a capacitor. Compared with other cancellation techniques, it is much simpler and requires no additional transistors and gate-drive circuitry since it merely adds a small copper winding and a small capacitor. By using this technique the size of the EMI filter can be reduced, especially for applications requiring high currents. In this paper, the new method for passive noise cancellation is applied to many popular converter and inverter topologies. The method, results, and ramifications of this technique are presented in order of appearance.

171 citations


Journal ArticleDOI
TL;DR: In this paper, the design, construction, and test of an integrated flywheel energy storage system with a homopolar inductor motor/generator and high-frequency drive is presented.
Abstract: The design, construction, and test of an integrated flywheel energy storage system with a homopolar inductor motor/generator and high-frequency drive is presented in this paper. The work is presented as an integrated design of flywheel system, motor, drive, and controller. The motor design features low rotor losses, a slotless stator, construction from robust and low cost materials, and a rotor that also serves as the energy storage rotor for the flywheel system. A high-frequency six-step drive scheme is used in place of pulsewidth modulation because of the high electrical frequencies. A speed-sensorless controller that works without state estimation is also described. A prototype of the flywheel system has been demonstrated at a power level of 9.4 kW, with an average system efficiency of 83% over a 30000-60000 r/min speed range.

165 citations


Journal ArticleDOI
12 Oct 2003
TL;DR: A small-sized passive electromagnetic interference (EMI) filter for the purpose of eliminating high-frequency shaft voltage and ground leakage current from an ac motor driven by a voltage-source pulsewidth-modulation inverter is proposed.
Abstract: This paper proposes a small-sized passive electromagnetic interference (EMI) filter for the purpose of eliminating high-frequency shaft voltage and ground leakage current from an ac motor driven by a voltage-source pulsewidth-modulation inverter. The filter requires access to the neutral point of the motor. A common-mode inductor is connected between the inverter and the motor. The neutral point of the motor is connected to the dc-bus midpoint via a resistor. The dc-bus midpoint is created by using two capacitors in series across the dc positive and negative buses. This unique circuit configuration makes the common-mode inductor effective in reducing the common-mode voltage appearing at the motor terminals. The validity and effectiveness of the EMI filter is verified by experimental results obtained from a 5-kVA laboratory system.

164 citations


Journal ArticleDOI
TL;DR: In this paper, a second-order RF bandpass filter based on active inductor has been implemented in a 0.35 /spl mu/m CMOS process, which has 28dB spurious-free-dynamic-range (SFDR) and total current consumption (including buffer stage) is 17 mA with 2.7-V power supply.
Abstract: In this paper, a second-order RF bandpass filter based on active inductor has been implemented in a 0.35 /spl mu/m CMOS process. Issues related to the intrinsic quality factor and dynamic range of the CMOS active inductor are addressed. Tuned at 900 MHz with Q=40, the filter has 28-dB spurious-free-dynamic-range (SFDR) and total current consumption (including buffer stage) is 17 mA with 2.7-V power supply. Experimental results also show the possibility of using them to build higher order RF filter and voltage-controlled oscillator (VCO).

163 citations


Journal ArticleDOI
TL;DR: In this article, a semi-active energy rate multi-modal vibration control technique is developed for a piezoceramic actuator coupled to a switching resistor/inductor shunt.
Abstract: In this paper, a novel semi-active energy rate multi-modal vibration control technique is developed for a piezoceramic actuator coupled to a switching resistor/inductor shunt. The technique works by briefly connecting a resistor/inductor shunt to a piezoceramic actuator in order to apply the necessary signed charge to allow energy dissipation. The switch timing is determined by a control scheme that observes the rate of energy change in controlled modes. The control scheme is developed in the paper, and is simplified to enable practical implementation. This new multi-modal control law is applied to both a simple numerical and an experimental test structure. The results from the numerical and experimental tests show that the energy rate multi-mode control law is able to dissipate energy from one, two and three modes of the flexible structures using a single actuator.

Patent
03 Feb 2003
TL;DR: In this article, an inductor is fabricated on a substrate having a top surface and a bottom surface, where a plurality of holes extending through the substrate are used to connect the top and bottom surfaces of the substrate.
Abstract: An inductor is fabricated on a substrate having a top surface and a bottom surface. The inductor includes a plurality of holes extending through the substrate, wherein the plurality of holes interconnect the top surface and the bottom surface of the substrate. The inductor also includes a plurality of conductive posts formed in the plurality of holes and a plurality of conductive segments formed on the top surface and on the bottom surface that interconnect the conductive posts such that a continuous conductive coil is formed. The inductor also includes a magnetic core that occupies substantially the entire volume enclosed by the conductive coil.

Journal ArticleDOI
TL;DR: In this paper, a unified constant-frequency integration (UCI) controller for a three-phase star-connected switch three-level rectifier (VIENNA) with unity-power-factor-correction is proposed.
Abstract: A unified constant-frequency integration (UCI) controller for a three-phase star-connected switch three-level rectifier (VIENNA) with unity-power-factor-correction is proposed. One of advantages of this rectifier is that the switch voltage stress is one half of the total output voltage. The proposed control approach is based on one-cycle control and features great simplicity and reliability: all three phases will be power factor corrected using one or two integrators with reset along with several flips-flops, comparators and logic and linear components. It does not require multipliers to scale the current reference according to the output power level as used in many other control approaches. In addition, the input voltage sensor is eliminated. It employs constant switching frequency modulation that is desirable for industrial applications. The proposed controller can operate by sensing either the inductor currents or the switching currents. If the switching currents are sensed, the cost is further reduced because switching currents are easier to sense comparing with inductor currents. The proposed approach is supported by experimental results.

Proceedings ArticleDOI
12 Oct 2003
TL;DR: In this paper, a set of four coupled inductors is applied to a four-phase interleaved 1 kW to 42 V DC/DC converter for automotive applications, and the performance is examined through simulations and experimental measurements.
Abstract: A set of four coupled inductors is applied to a four-phase interleaved 1 kW bi-directional 14 V to 42 V DC/DC converter for automotive applications. The coupled-inductor structure is optimized, and the performance is examined through simulations and experimental measurements. Although coupled inductors offer bigger advantages in applications that require fast transient response, they also have significant advantages in this type of application.

Journal ArticleDOI
L.F. Tiemeijer1, R.J. Havens1
TL;DR: In this article, a new de-embedding strategy using a physics-based lumped-element model for the test-structure parasitics calibrated on the frequency-dependent "open" and "short" dummy impedances is described, which reduces the experimental uncertainty on the deembedded figures of merit.
Abstract: The impedance errors remaining after conventional de-embedding for a high-speed transistor and a single-loop inductor test structure are investigated. A new de-embedding strategy using a physics-based lumped-element model for the test-structure parasitics calibrated on the frequency-dependent "open" and "short" dummy impedances is described, which reduces the experimental uncertainty on the de-embedded figures of merit. Using this new "calibrated lumped-element" de-embedding technique, we have been able to increase the "worst-case" values for the quality factor Q of a 0.6-nH 10-GHz single-loop inductor from 15 to 20 and for the f/sub max/ of a high-speed SiGe bipolar transistor from 80 to 110 GHz. The de-embedding technique presented here is of great importance to develop confidence in on-wafer S-parameter measurements taken at ever increasing microwave frequencies.

Proceedings ArticleDOI
19 Feb 2003
TL;DR: In this article, several techniques for integration of magnetic components in interleaved converters are analyzed and the integration of inductors in the same core for multiphase converters is analyzed from the point of view of size, losses and coupling.
Abstract: In this paper several techniques for integration of magnetic components in interleaved converters are analyzed Magnetic components define the way the energy is transformed Several opposite approaches can be considered: from decoupled integrated inductors to tightly coupled inductors The integration of inductors in the same core for multiphase converters is especially analyzed from the point of view of size, losses and coupling

PatentDOI
TL;DR: In this paper, a micro-mechanical pressure transducer is disclosed in which a capacitive transducers structure is integrated with an inductor coil to form a LC tank circuit, resonance frequency of which can be detected remotely by imposing an electromagnetic field on the transducers.
Abstract: A micro-mechanical pressure transducer is disclosed in which a capacitive transducer structure is integrated with an inductor coil to form a LC tank circuit, resonance frequency of which may be detected remotely by imposing an electromagnetic field on the transducer. The capacitive transducer structure comprises a conductive movable diaphragm, a fixed counter electrode, and a predetermined air gap between said diaphragm and electrode. The diaphragm deflects in response to an applied pressure differential, leading to a change of capacitance in the structure and hence a shift of resonance frequency of the LC tank circuit. The resonance frequency of the LC circuit can be remotely detected by measuring and determining the corresponding peak in electromagnetic impedance of the transducer.

Journal ArticleDOI
TL;DR: In this paper, the authors developed a simple wideband inductor model that contains lateral substrate resistance and capacitance to model the decrease in the series resistance at high frequencies related to lateral coupling through the silicon substrate.
Abstract: In this paper, we developed a simple wide-band inductor model that contains lateral substrate resistance and capacitance to model the decrease in the series resistance at high frequencies related to lateral coupling through the silicon substrate. The model accurately predicts the equivalent series resistance and inductance over a wide-frequency range. Since it has frequency-independent elements, the proposed model can be easily integrated in SPICE-compatible simulators. The proposed model has been verified with measured results of inductors fabricated in a 0.18-/spl mu/m six-metal CMOS process. We also demonstrate the validity of the proposed model for shielded inductors. The proposed model shows excellent agreement with measured data over the whole frequency range.

Patent
24 Jul 2003
TL;DR: In this paper, a circuit and method for providing closed loop control using constant current switching techniques is described, where the LED arrays are connected through an inductor to a current switching control section that switches current to ground or recirculates the current to maintain LED current flow within a desired range.
Abstract: A circuit and method for providing closed loop control using constant current switching techniques is disclosed herein. By controlling the current supplied to high intensity light emitting diodes (LEDs) using the techniques and circuits described, high intensity LEDs can be operated at or near their maximum capacity without danger of overloading the LEDs, and without using excess amounts of current. A circuit as described herein, has multiple high side switches, each of which is connected to an LED array. The LED arrays are in turn connected through an inductor to a current switching control section that switches current to ground, or recirculates the current to maintain LED current flow within a desired range.

Book ChapterDOI
01 Jan 2003
TL;DR: In this article, the results of a comprehensive investigation into the characteristics and optimization of inductors fabricated with the top-level metal of a submicron silicon VLSI process are presented.
Abstract: The results of a comprehensive investigation into the characteristics and optimization of Inductors fabricated with the top-level metal of a submicron silicon VLSI process are presented. A computer program which extncts a physics-based model of microstrip components that is suitable for circuit (SPICE) simulation has been used to evaluate the effect of variations in melallization, layout geometry, and substrate parameters upon monolithic inductor performance. Three-dimensional (3-D) numerical simulations and experimental measurements of inductors were also used to benchmark the model aecuncy. It is shown in this work that low inductor Q is primarily due to the restrictions imposed by the thin interconnect metallization available in most very large scale integration (VLSI) technolocies, and that computer optimization of the inductor layout can be used to achieve a 50% improvement in component Q-factor over unoptimized designs.

Patent
25 Nov 2003
TL;DR: In this article, a dual-output buck converter and control method that facilitates power conversion by converting a single DC power source/supply into two separate DC outputs, each of which can be configured to provide a selected/desired voltage by selection of respective duty cycles is presented.
Abstract: A single-inductor dual-output buck converter and control method that facilitates power conversion by converting a single DC power source/supply into two separate DC outputs, each of which can be configured to provide a selected/desired voltage by selection of respective duty cycles. The topology of the inverter includes a pair of diodes or switches that can selectively re-circulate inductor current. The converter is generally operated at a fixed frequency with four stages of operation. A first and third stage of operation provide power to a first and second output, respectively. A second and fourth stage of operation re-circulate inductor current and can partially recharge a battery type power source. The power output for each stage (voltage and current) can be selectively obtained by computing and employing appropriate time periods for the stages of operation that correspond to appropriate duty cycles.

Journal ArticleDOI
08 Apr 2003
TL;DR: In this article, a two-cell interleaved boost converter with coupled inductors is used to match the photovoltaic system to the load and to operate the solar cell array at maximum power point.
Abstract: A photovoltaic generator exhibits nonlinear voltage-current characteristics and its maximum power point varies with solar radiation. A two-cell interleaved boost converter with coupled inductors is used to match the photovoltaic system to the load and to operate the solar cell array at maximum power point. A maximum power point tracking algorithm is developed using only load voltage information, eliminating the array current detection. The present converter system has the advantages of low ripple content, both on the load and source side, improved efficiency and reduced switch stress, as compared to noncoupled two-cell interleaved converters. As a result, a lower value of array capacitance is sufficient for smoothing the array voltage and current. Analytical expressions for the photovoltaic source and interleaved boost converter, corresponding to maximum power point operation of the SCA, are derived. Experimental results are presented to demonstrate the suitability of this converter system. Few experimental observations are also presented for partial shading conditions. Further, a comparative study of coupled and noncoupled interleaved boost converters for photovoltaic applications is made. These studies reveal that, by introducing coupling among the parallel branch inductors, it is possible to improve steady-state performance while maintaining the dynamic performance of the photovoltaic system.

Patent
03 Feb 2003
TL;DR: In this article, a ZCS discontinuous mode PFC controller with a power saving modulator is presented, where the controller turns on through the feedback resistor and the parasitic diode of the controller, thus eliminating the need for a startup resistor.
Abstract: The present invention discloses a ZCS discontinuous mode PFC controller having a power saving modulator. The controller turns on through the feedback resistor and the parasitic diode of the controller, thus eliminating the need for a startup resistor. To achieve ZCS, the inductor current is released to zero, while the switching signal is off, before the next switching cycle starts. In order to decrease the switching frequency for light load conditions, an off-time delay is inserted right before the start of every switching cycle. The off-time delay is modulated to be the function of the feedback voltage and supply voltage. When the supply voltage is lower than the limit voltage, the off-time delay will decrease to inhibit the decrease of a switching frequency therefore prevents a low supply voltage. The switching frequency is decreased in accordance with the decrease of the load. Consequently, the switching losses and power consumption for light load and no load conditions are reduced.

Journal ArticleDOI
TL;DR: In this article, a surface micro-machined inductor with its coil axis parallel to the substrate plane is presented, which exhibits record-high quality factors (Q) of over 70 at 1 GHz.
Abstract: Integrated high-Q coils are much sought after because they enable high-quality radio-frequency circuits that do not rely on off-chip discretes. We present a novel surface micro-machined inductor with its coil axis parallel to the substrate plane. Coils fabricated on standard unaltered low-resistance silicon exhibit record-high-quality factors (Q) of over 70 at 1 GHz. The devices are made by three-dimensional (3-D) self-assembly of stress-engineered structures fabricated with standard semiconductor batch processing techniques. We also designed, fabricated, and characterized silicon Bi-CMOS L-C oscillators built around these coils. Compared side by side against state-of-the-art planar spirals, they produce a 12.3 dB lower phase noise at 100 kHz offset, and 14.6 dB after normalizing to frequency and power.

Patent
20 Oct 2003
TL;DR: An induction choke in a petroleum well where a voltage potential is developed across the choke to power and communicate with devices and sensors in the well is discussed in this article, where a controllable gas lift valve, sensor, or other device is coupled to the tubing.
Abstract: An induction choke in a petroleum well where a voltage potential is developed across the choke to power and communicate with devices and sensors in the well. Preferably, the induction choke is a ferromagnetic material and acts as an impedance to a time-varying current, e.g. AC. The petroleum well includes a cased wellbore having a tubing string positioned within and longitudinally extending within the casing. A controllable gas lift valve, sensor, or other device is coupled to the tubing. The valve sensor, or other device is powered and controlled from the surface. Communication signals and power are sent from the surface using the tubing, casing, or liner as the conductor with a casing or earth ground. For example, AC current is directed down a casing or tubing or a lateral where the current encounters a choke. The voltage potential developed across the choke is used to power electronic devices and sensors near the choke. Such induction chokes may be used in many other applications having an elongated conductor such as a pipe, where it is desirable to power or communicate with a valve, sensor, or other device without providing a dedicated power or communications cable.

Journal ArticleDOI
TL;DR: In this article, a zero-current transition (ZCT) PWM DC/DC converters without additional current stress and conduction loss on the main switch during the resonance period of the auxiliary cell is presented.
Abstract: This paper presents novel zero-current-transition (ZCT) PWM DC/DC converters without additional current stress and conduction loss on the main switch during the resonance period of the auxiliary cell. The auxiliary cell consists of a resonant inductor, a resonant capacitor, an auxiliary switch and an auxiliary diode in parallel with the main switch and the zero-current-switching (ZCS) ranges of the main and the auxiliary switch of the proposed converters are entirely achieved by operating the auxiliary cell. In addition, the resonant inductor of the proposed ZCT cell helps soft turn-on of the main switch. The theoretical analysis and the operation principle of the new ZCT technique are described in detail using a boost converter as an example. To verify the validity of the proposed ZCT technique, the simulation and the experiment were performed on the nonisolated and the isolated converter, respectively. Here, the nonisolated converter is a boost converter having 100 kHz switching frequency, 1 kW rating power, and the isolated converter is a full-bridge (FB) converter having 50 kHz switching frequency, 1 kW rating power.

Patent
25 Mar 2003
TL;DR: In this article, a remote access device with a single form for the first, second and third inductors is proposed, where the first and second inductors are wound on the form.
Abstract: A remote access device which may comprise an antenna having a first inductor with a first axis, a second inductor with a second axis, and a third inductor with a third axis, where the first, second and third axes may be oriented substantially perpendicular to each other, respectively, such that the first inductor generates a first magnetic field associated with a first plane, the second inductor generates a second magnetic field associated with a second plane different than the first plane, and the third inductor generates a third magnetic field associated with a third plane different than the first and second planes. The remote access device preferably includes a single form for the first, second and third inductors, where the first, second and third inductors are each wound on the form.

Journal ArticleDOI
TL;DR: In this paper, the use of printed circuit board (PCB) integrated inductors for low power DC/DC buck converters is discussed, and a 4.7 /spl mu/H PCB integrated inductor with dc current handling of up to 500 mA is presented.
Abstract: This paper discusses the use of printed circuit board (PCB) integrated inductors for low power DC/DC buck converters. Coreless, magnetic plates and closed core structures are compared in terms of achievable inductance, power handling and efficiency in a footprint of 10 /spl times/ 10 mm/sup 2/. The magnetic layers consist of electroplated NiFe, so that the process is fully compatible with standard PCB process. Analytic and finite element method (FEM) methods are applied to predict inductor performance for typical current waveforms encountered in a buck converter. Conventional magnetic design procedures are applied to define optimum winding and core structures for typical inductor specifications. A 4.7 /spl mu/H PCB integrated inductor with dc current handling of up to 500 mA is presented. This inductor is employed in a 1.5 W buck converter using a commercial control integrated circuit (IC). The footprint of the entire converter measures 10 /spl times/ 10 mm/sup 2/ and is built on top of the integrated inductor to demonstrate the concept of integrated passives in power electronic circuits to achieve ultra flat and compact converter solutions.

Journal ArticleDOI
TL;DR: In this paper, the authors discuss the development of two types of on-chip 3D inductors, a vertical spiral inductor and a solenoid inductor, by using a 3D assembly process called plastic deformation magnetic assembly.
Abstract: On-chip inductors are critical for enabling portable power-efficient wireless communication systems. Existing on-chip spiral inductors based on conventional planar integrated-circuit fabrication technology suffer from substrate loss and parasitics, and have relatively large footprints. In this paper, we discuss the development of two types of on-chip three-dimensional (3-D) inductors-a vertical spiral inductor and a solenoid inductor-by using a 3-D assembly process called plastic deformation magnetic assembly. Prototype vertical spiral inductors and solenoid inductors have been fabricated and tested. Experimental results show that the vertical spiral inductors can achieve better performance and a smaller footprint than the in-plane ones.

Journal ArticleDOI
TL;DR: In this article, a distributed capacitance model for monolithic spiral inductors is developed to predict the equivalent coupling capacitances C/sub p/ between the two terminals and the equivalent capacitance between the metal track and the substrate c/sub sub/.
Abstract: In this paper, a distributed capacitance model (DCM) for monolithic spiral inductors is developed to predict the equivalent coupling capacitances C/sub p/ between the two terminals and the equivalent capacitance between the metal track and the substrate C/sub sub/. Therefore, the characteristics of inductors such as the S parameter, the quality factor Q, and the self-resonant frequency f/sub SR/ can be predicted by its series inductance, equivalent capacitances, and series resistance. A large number of inductors have been implemented in 0.25- and 0.35-/spl mu/m CMOS processes to demonstrate the prediction accuracy. For planar and multilayer inductors, DCM can provide a quick and accurate assessment to the design of monolithic spiral inductors.