A toroidal inductor integrated in a standard CMOS process

Vandi, Luca; Andreani, Pietro; Temporiti, Enrico; Sacchi, E.; Bietti, I.; Ghezzi, Cesare; Castello, R.

doi:10.1007/s10470-006-9153-y

Cited by 6 publications

(3 citation statements)

References 5 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…3. In (18), S yT and S zT denote thê y-directed lateral span and theẑ-directed path of the winding, respectively, as it carries the toroidal currents on its outer surface. S yT includes the surfaces in Regions 1, 3, and 5 in Fig.…”

Section: Equivalent Circuitmentioning

confidence: 99%

Modeling and Measured Verification of Stored Energy and Loss in MEMS Toroidal Inductors

Araghchini

Kim

et al. 2014

IEEE Trans. on Ind. Applicat.

View full text Add to dashboard Cite

This paper presents the derivation and verification of a sinusoidal steady-state equivalent-circuit model for microfabricated inductors developed for use in integrated power electronics. These inductors have a low profile, a toroidal air core, and a single-layer winding fabricated via high-aspect-ratio molding and electroplating. Such inductors inevitably have a significant gap between winding turns. This makes the equivalent resistance more difficult to model. The low profile increases the significance of the energy that is stored in the winding, which together with the winding gap makes the equivalent inductance more difficult to model. The models presented here account for these effects. Finally, the models are verified against results from 2-D and 3-D finiteelement analysis (2-D FEA and 3-D FEA) direct measurement, and from in-circuit experimentation. In all cases, the equivalent-circuit model is observed to be accurate to within several percentage.

show abstract

Section: Equivalent Circuitmentioning

confidence: 99%

Modeling and Measured Verification of Stored Energy and Loss in MEMS Toroidal Inductors

Araghchini

Kim

et al. 2014

IEEE Trans. on Ind. Applicat.

View full text Add to dashboard Cite

show abstract

“…Planar spiral and solenoidal air-core inductors produce significant external fields which may cause losses in nearby conductors and electromagnetic interference problems, but toroidal geometries can mitigate these concerns. Microfabricated toroidal inductors have been fabricated above substrates [45], [46], as well as embedded in substrates, most commonly in printed circuit boards in which toroidal magnetics are formed using copper traces and plated-through vias [47], [48]. Similar inductors and transformers have also been successfully electroplated in copper on Pyrex substrates [49], [50].…”

Section: A Toroidal Air-core Inductorsmentioning

confidence: 99%

A Technology Overview of the PowerChip Development Program

Araghchini

Chen

Doan-Nguyen

et al. 2013

IEEE Trans. Power Electron.

View full text Add to dashboard Cite

Abstract-The PowerChip research program is developing technologies to radically improve the size, integration, and performance of power electronics operating at up to grid-scale voltages (e.g., up to 200 V) and low-to-moderate power levels (e.g., up to 50 W) and demonstrating the technologies in a high-efficiency light-emitting diode driver, as an example application. This paper presents an overview of the program and of the progress toward meeting the program goals. Key program aspects and progress in advanced nitride power devices and device reliability, integrated highfrequency magnetics and magnetic materials, and high-frequency converter architectures are summarized.Index Terms-Gallium nitride, high frequency (HF), integrated magnetics, integrated power converter, light-emitting diode (LED) driver, PwrSoC.

show abstract

“…A challenge of this geometry for power applications is that the flux cross-sectional area and therefore the thickness of these inductors should be substantial. Previous miniaturized toroidal air-core inductors, including copperwinding toroids fabricated using printed circuit boards (PCB), silicon and Pyrex substrates have been demonstrated [14][15][16][17][18]. Often, however, these geometries possess fabrication or resolution limitations on the ultimate size and value of achievable inductance.…”

Section: Introductionmentioning

confidence: 99%

Microfabrication of air core power inductors with metal-encapsulated polymer vias

Kim

Herrault²,

Yu³

et al. 2013

J. Micromech. Microeng.

View full text Add to dashboard Cite

This paper reports three-dimensional (3-D) microfabricated toroidal inductors intended for power electronics applications. A key fabrication advance is the exploitation of thick metal encapsulation of polymer pillars to form a vertical via interconnections. The radial conductors of the toroidal inductor are formed by conventional plating-through-mold techniques, while the vertical windings (up to 650 µm in height) are formed by polymer cores with metal plated on their external surfaces. This encapsulated polymer approach not only significantly reduces the required plating time but also exploits the relative ease of fabricating high-aspect-ratio SU-8 pillars. To form the top radial conductors, non-photopatternable SU-8 is introduced as a thick sacrificial layer. Two toroidal inductor geometries were fabricated and tested. The first inductor had an inner diameter of 2 mm, an outer diameter of 6 mm, 25 turns and a vertical via height of 650 µm. The second inductor had an inner diameter of 4 mm, an outer diameter of 8 mm, 50 turns and a vertical via height of 650 µm. Both inductor geometries were successfully fabricated and characterized in the frequency range of 0.1−100 MHz. Characterization results of the 25-and 50-turn inductors showed an average inductance of 76 and 200 nH, a low frequency (0.1 MHz) resistance of 0.2 and 1 and a quality factor of 35 and 24 at 100 MHz, respectively. Finite-element simulations of the inductors were performed and agreed with the measured results to within 8%. The turn-to-turn breakdown voltage was measured to be in excess of 800 V and currents as high as 0.5 A could be successfully carried by the inductor windings.

show abstract

A toroidal inductor integrated in a standard CMOS process

Cited by 6 publications

References 5 publications

Modeling and Measured Verification of Stored Energy and Loss in MEMS Toroidal Inductors

Modeling and Measured Verification of Stored Energy and Loss in MEMS Toroidal Inductors

A Technology Overview of the PowerChip Development Program

Microfabrication of air core power inductors with metal-encapsulated polymer vias

Contact Info

Product

Resources

About