Novel planar PCB integrated transformer

Abstract

A planar integrated transformer structure has been proposed. The transformer structure may include a top core, a bottom core, and one or more center posts interposed between the top core and the bottom core. The transformer structure may also include a transformer having a primary winding and a secondary winding, each of the primary winding and the secondary winding surrounding at least one of the one or more center posts. One of the primary winding or the secondary winding may be configured to function as an inductor. At least one of the one or more center posts may be shared between the transformer and the inductor.

Description

[Technical Field]

[0001] [CROSS-REFERENCE TO RELATED APPLICATIONS] This application claims priority to U.S. Provisional Patent Application No. 63 / 483,418, entitled "NOVEL PLANAR PCB INTEGRATED TRANSFORMERS," filed February 6, 2023, the disclosure of which is incorporated herein by reference in its entirety.

[0002] The present disclosure relates to a novel planar printed circuit board (PCB) integrated transformer. [Background technology]

[0003] PCB-based transformers can be used in low-power and signal processing applications. They utilize PCB processes to achieve low-cost windings. Traditional PCB transformers can use discrete components. Discrete resonant inductors are generally required for most magnetic-based power converter topologies, such as LC resonant converters. While journal publications exist on integrated transformer structures (e.g., listed below), this structure does not solve the problem of stray magnetic fields (either from the magnetic structure or passive shielding). Summary of the Invention

[0004] Each of the embodiments disclosed herein has several aspects, no single one of which is solely responsible for the desirable attributes of the present disclosure. Without limiting the scope of the present disclosure, its more prominent features will now be briefly described. After considering this description, and particularly after reading the section entitled "Detailed Description of the Invention," you will understand how the features of the embodiments described herein provide advantages over existing transformers.

[0005] One aspect is an integrated magnetic structure comprising a top core, a bottom core, one or more posts interposed between the top core and the bottom core, a center post different from and spaced apart from the one or more posts, an inductor portion comprising a first portion of a primary winding and a first portion of a secondary winding, and a transformer integrated with the inductor portion by sharing one or more of the posts.

[0006] In the above integrated magnetic structure, the transformer includes a second portion of the primary winding and a second portion of the secondary winding.

[0007] In the above integrated magnetic structure, the second portion of the primary winding and the second portion of the secondary winding overlap each other vertically.

[0008] In the integrated magnetic structure described above, the primary winding surrounds the secondary winding.

[0009] In the above integrated magnetic structure, at least one of the primary winding or the secondary winding includes an interleaved winding structure.

[0010] In the above-described integrated magnetic structure, the center post is disposed perpendicular to the center position of the bottom core of the inductor portion.

[0011] In the above-described integrated magnetic structure, the one or more posts, the transformer, the inductor portion, and the center post are disposed within a completely sealed housing.

[0012] In the above-described integrated magnetic structure, a flux-forming air gap is formed at each post of the one or more posts and the center post.

[0013] In the above integrated magnetic structure, a flux forming air gap is formed on the center post.

[0014] In the above integrated magnetic structure, two or more symmetrical air gaps are formed in the inductor portion.

[0015] In the above-described integrated magnetic structure, the integrated magnetic structure further comprises a metallic shielding plate disposed adjacent to the one or more posts and configured to at least partially shield stray magnetic fields.

[0016] Another aspect is an integrated magnetic structure including a top core, a bottom core, one or more posts interposed between the top core and the bottom core, an inductor portion having a center post and a flux shaping plate disposed on top of the center post, and a transformer integrated with the inductor portion by sharing one or more of the posts.

[0017] In the above integrated magnetic structure, the inductor portion further comprises a first portion of the primary winding and a first portion of the secondary winding.

[0018] In the above integrated magnetic structure, the transformer includes a second portion of the primary winding and a second portion of the secondary winding.

[0019] In the integrated magnetic structure described above, the primary winding surrounds the secondary winding.

[0020] In the above integrated magnetic structure, the second portion of the primary winding and the second portion of the secondary winding overlap each other vertically.

[0021] In the above-described integrated magnetic structure, a flux-forming air gap is formed at each post of the one or more posts and the center post.

[0022] In the above integrated magnetic structure, a flux forming air gap is formed on the center post.

[0023] Another aspect is an integrated magnetic structure comprising: a top core including a first portion and a second portion, wherein the first portion and the second portion of the top core are positioned at different heights; a bottom core; an inductor portion comprising: one or more posts interposed between the top core and the bottom core; a center post; a first portion of a primary winding; and a transformer disposed between the second portion of the top core and the bottom core, wherein the transformer comprises a second portion of the primary winding and a second portion of the secondary winding.

[0024] In the above-described integrated magnetic structure, a flux-forming air gap is formed at each post of the one or more posts and the center post.

[0025] In the above integrated magnetic structure, a flux forming air gap is formed on the center post.

[0026] In the above integrated magnetic structure, the first portion of the top core is disposed on top of the transformer, and the second portion of the top core is disposed on top of the inductor portion.

[0027] Any of the features of an embodiment may be applicable to all embodiments identified herein. Furthermore, any of the features of an embodiment may be combined in any way independently, partially, or in whole with other embodiments described herein, e.g., one, two, or three or more embodiments may be combined in whole or in part. Furthermore, any of the features of an embodiment may be made optional with respect to other embodiments. [Brief explanation of the drawings]

[0028] The foregoing and other features of the present disclosure will become more fully apparent from the following description and appended claims, taken in conjunction with the accompanying drawings, in which: The present disclosure will be described with additional specificity and detail through the use of the accompanying drawings, with the understanding that these drawings illustrate only some embodiments in accordance with the present disclosure and should not be considered limiting of its scope.

[0029] [Figure 1A] FIG. 1 shows a Litz-based transformer and inductor. [Figure 1B] FIG. 1 shows a Litz-based transformer and inductor. [Figure 1C] FIG. 1 shows a Litz-based transformer and inductor.

[0030] [Figure 2A] FIG. 1 illustrates a non-planar magnetic structure.

[0031] [Figure 2B] FIG. 1 illustrates an example of a planar magnetic structure according to some embodiments.

[0032] [Figure 3A] FIG. 10 illustrates another example of a non-planar magnetic structure.

[0033] [Figure 3B] FIG. 1 illustrates another example of a planar magnetic structure according to some embodiments.

[0034] [Figure 4A] FIG. 10 is a diagram showing a circuit model in which a transformer and an inductor have discrete structures.

[0035] [Figure 4B] FIG. 1 illustrates a circuit model in which a transformer portion and an inductor portion are integrated, according to some embodiments.

[0036] [Figure 5]1A-1C illustrate examples of integrated transformer structures according to some embodiments.

[0037] [Figure 6A] FIG. 1 illustrates an example of a fully enclosed pot core integrated planar design according to some embodiments.

[0038] [Figure 6B] A comparison diagram is shown in which a discrete transformer / inductor section is compared to an integrated transformer.

[0039] [Figure 6C] FIG. 10 illustrates another example of a fully enclosed pot core integrated planar design according to some embodiments.

[0040] [Figure 6D] FIG. 6D is a perspective view of the fully enclosed pot core integrated planar structure of FIG. 6A or FIG. 6C according to some embodiments.

[0041] [Figure 6E] FIG. 10 illustrates near-field reduction of a pot core structure compared to an EE core structure according to some embodiments.

[0042] [Figure 6F] 1 shows the current density distribution in a closed pot core structure without flux shaping plates.

[0043] [Figure 6G] 1 shows the current density distribution in a closed pot core design with flux shaping plates.

[0044] [Figure 7A] FIG. 1 illustrates an example of a hybrid pot core integrated planar design according to some embodiments.

[0045] [Figure 7B] FIG. 10 illustrates another example of a hybrid pot core integrated planar structure according to some embodiments.

[0046] [Figure 8A] FIG. 1 illustrates the concept of core lamination to minimize eddy currents.

[0047] [Figure 8B] 1A-1C illustrate an example structure for improving magnetic flux density sharing in a split core by using an air gap on the center post in the magnetization flux path, according to some embodiments.

[0048] [Figure 8C] 1A-1C illustrate exemplary structures for improving magnetic flux density sharing in split cores by using consistent bond wire thickness control in each laminated core, according to some embodiments.

[0049] [Figure 8D] FIG. 10 shows an example of an alternative structure.

[0050] [Figure 9A] FIG. 1 illustrates high current termination in a non-planar magnetic with wire windings.

[0051] [Figure 9B] FIG. 1 illustrates high current termination in a non-planar magnetic with busbar windings.

[0052] [Figure 9C] FIG. 1 illustrates an example of a low-loss high-current PCB winding termination. [Figure 9D] FIG. 1 illustrates an example of a low-loss high-current PCB winding termination.

[0053] [Figure 10A] FIG. 1 shows PCB winding terminations (in and out) placed side by side.

[0054] [Figure 10B] FIG. 1 shows overlapping PCB winding terminations (in and out).

[0055] [Figure 11A] 1A-1C illustrate a fully enclosed pot core integrated planar structure according to some embodiments. [Figure 11B] 1A-1C illustrate a fully enclosed pot core integrated planar structure according to some embodiments.

[0056] [Figure 12A] 10A-10C illustrate an open EE 3-leg structure with and without flux forming according to some embodiments. [Figure 12B] 10A-10C illustrate an open EE 3-leg structure with and without flux forming according to some embodiments. [Figure 12C] 10A-10C illustrate an open EE 3-leg structure with and without flux forming according to some embodiments. [Figure 12D] 10A-10C illustrate an open EE 3-leg structure with and without flux forming according to some embodiments. [Figure 12E] 10A-10C illustrate an open EE 3-leg structure with and without flux forming according to some embodiments.

[0057] [Figure 12F] FIG. 10 shows simulation results of inductive losses in an adjacent metal heat sink.

[0058] [Figure 13A] FIG. 10 illustrates an open EE4-leg structure without flux shaping, according to some embodiments.

[0059] [Figure 13B] FIG. 1 illustrates an open EE 4-leg structure with flux shaping and symmetric air gap according to some embodiments.

[0060] [Figure 13C] FIG. 1 illustrates an open EE 4-leg structure with flux shaping and asymmetric air gap according to some embodiments.

[0061] [Figure 14] FIG. 1 illustrates near-field reduction of an open EE core structure with a metal shield, according to some embodiments.

[0062] [Figure 15A] FIG. 1 illustrates an example of an EE core structure with a metal shield according to some embodiments.

[0063] [Figure 15B] FIG. 1 illustrates an example of a metal shielding application according to some embodiments.

[0064] [Figure 15B] FIG. 10 illustrates another example of an EE core structure with a metal shield according to some embodiments.

[0065] [Figure 16A] FIG. 1 illustrates the concept of a partially interleaved winding structure between two power stages. [Figure 16B] FIG. 1 illustrates the concept of a partially interleaved winding structure between two power stages. [Figure 16C] FIG. 1 illustrates the concept of a partially interleaved winding structure between two power stages. [Figure 16D] FIG. 1 illustrates the concept of a partially interleaved winding structure between two power stages.

[0066] [Figure 16E] FIG. 16D is a diagram showing an example of an induced current density distribution in a winding structure without winding interleaving between the two stages shown in FIG. 16C.

[0067] [Figure 16F] FIG. 16E shows an example of an induced current density distribution for a partially interleaved winding structure having winding interleaving between two stages as shown in FIG. 16D.

[0068] Embodiments of the present disclosure and their advantages are best understood by reference to the following detailed description: It should be understood that like reference numerals have been used to identify like elements shown in one or more of the drawings, and that the designations therein are intended to illustrate, but not to limit, embodiments of the present disclosure. DETAILED DESCRIPTION OF THE INVENTION

[0069] Various embodiments of novel planar PCB-integrated transformers are provided herein. Magnetic components, such as inductors and transformers, generally include conductors (e.g., windings) wound around a magnetic core. They come in many shapes and sizes and can perform different functions (such as voltage transformation, isolation, and electromagnetic interference (EMI) mitigation). Various embodiments provide novel planar PCB-integrated transformer structures that use PCB traces as transformer windings to achieve low profiles and high power densities for high-frequency power converter applications. Planar structures generally cost less than their wire-wound counterparts and can significantly minimize supply chain constraints by reducing the number of unique suppliers for assembling magnetic components, for example, from six or more to approximately one or two.

[0070] An example of an integrated transformer structure can include an inductor integrated into the transformer structure. The integration of the inductor and transformer results in reduced winding losses and reduced footprint compared to using separate inductors and transformers. These structures allow the flexibility to have inductance either throughout the primary or on the secondary. In addition, some structures also allow the flexibility to distribute inductance symmetrically or asymmetrically across both the primary and secondary windings. The proposed integrated transformer structure also includes flux shaping features to minimize conduction losses.

[0071] Various embodiments can be used in electric vehicles, stationary storage, powered walls, megapacks, battery chargers, or on-board chargers for autonomous driving hardware. Power electronic converters requiring isolation / voltage step ratios and / or energy storage require magnetic components. Various embodiments cover all different concepts / structures that can be used in any power converter designed for any of the above applications. In some embodiments, the core structure can be made of magnetic materials such as ferrite and powder core.

[0072] High-power, high-frequency applications result in large-sized integrated transformer structures. These high-power integrated transformer structures may require core lamination to minimize eddy current losses within the core. Splitting the core can be used in high-power integrated transformer structures, but these split cores can pose technical challenges regarding the magnetic flux density distribution between the various core split structures. Some embodiments disclosed herein can improve the magnetic flux density distribution between different split cores. For example, providing an air gap in the center post can improve the magnetic flux density distribution. As another example, the magnetic flux density distribution can be improved by providing a uniform bond wire thickness between the top and bottom core halves.

[0073] Integrated transformer structures can potentially generate large stray magnetic fields, which can cause electromagnetic compatibility (EMC) issues for nearby components. To address these shortcomings, the present disclosure provides various integrated inductor and transformer structures that can minimize existing stray magnetic fields and confine strong magnetic fields within the core structure. The present disclosure also provides other structures with metal shielding covers. Various embodiments can provide novel shielding structures to minimize near-fields from planar transformer structures with integrated resonant inductors.

[0074] Various embodiments provide novel winding design techniques that overlap incoming and outgoing current carrying PCB traces of the same winding to minimize stray magnetic fields / termination losses. Various embodiments also provide the concept of overlapping windings from parallel power converter stages to achieve magnetic flux cancellation, reduce losses in heat sinks, and / or reduce overall footprint.

[0075] According to various embodiments, power converters designed using high-power planar magnetics can significantly increase power capability at low cost. Some embodiments can completely eliminate parts of the supply chain (e.g., suppliers that assemble different components such as cores, windings, and bobbins to manufacture transformers / inductors). This can be essential to reaching mass production speeds at lower costs.

[0076] Various embodiments may also provide manufacturing improvements: for example, LV termination using bolted joints requiring precise micro-resistance measurements has proven difficult, but with planar magnetics, conductors on a PCB can be integrated directly onto the PCB (e.g., printed circuit board assembly, PCBA).

[0077] Various embodiments provide a fully enclosed pot core integrated planar design that can minimize stray fields compared to an open EE core design. Various embodiments also provide a hybrid pot core integrated planar design that can further reduce weight and cost compared to a fully enclosed pot core design while maintaining the benefits of minimized stray fields.

[0078] Various embodiments provide a sealed pot core structure (e.g., a fully sealed pot core integrated planar structure) that can reduce the number of required PCB layers compared to other structures with overlapping winding sections that can integrate and distribute resonant inductors. Various embodiments provide open EE core structures, including three-legged open EE cores and four-legged open EE core structures. The three-legged open EE core structure can minimize core size and footprint. The four-legged open EE core structure can have a lower stray magnetic field compared to the three-legged open EE core structure and can also provide an integrated resonant inductor that is symmetrically or asymmetrically distributed on the primary or secondary side.

[0079] 1A-1C illustrate high-frequency power magnetics such as Litz-based transformers and inductors. Specifically, FIGS. 1A-1C illustrate conventional DC-DC (DC-DC) converters and chargers including inductors and transformers that can be used in various applications, such as electronic vehicles and chargers. For example, FIG. 1A illustrates a DC-DC converter that can include a transformer and an inductor. FIG. 1B illustrates a charger that can include a transformer and an inductor. Furthermore, FIG. 1C illustrates an example of a DC-DC converter that can include a transformer and an inductor.

[0080] Conventional converters and / or chargers utilize litz wire-based magnetics (transformers and inductors) and can offer low losses in certain frequency ranges, such as the 100-500 kHz frequency range and low proximity / skin effect losses in litz wire. However, several technical challenges can exist, including higher cost, high thermal resistance in the core and windings, a limited supply chain (e.g., limited certified litz wire suppliers), power density (typically the highest component in a converter), and / or complexity / loss in winding terminations (for high current litz wire terminations).

[0081] 2A shows an example of an exploded view of a conventional non-planar magnetic structure 200. Generally, a non-planar magnetic structure 200, such as a Litz wire-based magnetic, can have many bits and pieces that can result in a complex manufacturing assembly process. For example, the non-planar magnetic structure 200 can include a housing 202, a core 204, windings 206, 208, terminals 210, and a bobbin 212.

[0082] 2B illustrates an example of a planar magnetic structure 250 according to some embodiments. Planar magnetic structure 250 can generally include relatively few parts compared to non-planar magnetic structures 200 (e.g., Litz wire-based magnetics) and can eliminate manufacturing process complexities such as terminations and windings. For example, planar magnetic structure 250 can include core 252, insulator 254, and PCB windings 256. Thus, windings 206, 208, terminals 210, and bobbin 212 included in conventional non-planar magnetic structures 200 can be integrated into PCB windings 256 of planar magnetic structure 250.

[0083] FIG. 3A is a diagram illustrating another example of a non-planar magnetic structure 300. In some embodiments, the non-planar magnetic structure 300 can include a non-planar magnetic structure 302, a film capacitor 304, a PCB 306, a transistor (e.g., a MOSFET) 308, a thermal interface material 310, a base on a heat sink 312, and a heat sink 314. FIG. 3B is a diagram illustrating another example of a planar magnetic structure 350, in some embodiments. In some embodiments, the planar magnetic structure 350 can include a non-planar magnetic structure 352A / 352B, a film capacitor 354, a PCB 356, a transistor (e.g., a MOSFET) 358, a thermal interface material 360, a base on a heat sink 362, and a heat sink 364. As shown in FIGS. 3A and 3B, the height of the non-planar magnetic structure 302 can be greater than the height of the planar magnetic structures 352A / 352B.

[0084] FIG. 4A shows a schematic diagram of a conventional discrete transformer and inductor 400. For example, the discrete transformer and inductor 400 may include an inductor 402, a transformer 404, and a capacitor 406. In this example shown in FIG. 4A, each of the inductor 402 and the transformer 404 may be a discrete component. FIG. 4B shows a schematic diagram of an example of an integrated magnetic 450 according to some embodiments. For example, the inductor 402 and the transformer 404 may be integrated as a component 408 (e.g., an integrated magnetic), as shown in FIG. 4B.

[0085] FIG. 5 illustrates various examples of integrated transformer structures 500 according to some embodiments. The integrated transformer structure 500 can include a closed pot core structure 510 and an open EE core structure 520. The closed pot core structure 510 can include a pot core structure with or without flux shaping 512 (Example 1; see, e.g., FIGS. 6A and 6C). The closed pot core structure 510 can also include a hybrid pot core structure and an EE core structure with or without flux shaping 514 (Example 2; see, e.g., FIGS. 7A and 7B). The closed pot core structure 510 can further include a closed five-legged pot core structure with or without flux shaping 516 (Example 3; FIG. 11). The open EE core structure 520 can include an open EE three-legged structure with flux shaping 522 (Example 4; see, e.g., FIGS. 12A-12E). The open EE core structure 520 can also include open EE4 legs with or without flux shaping with a distributed symmetric / asymmetric structure 524 that is independent of resonant inductance (Example 5; see, e.g., Figures 13A-13C).

[0086] FIG. 6A illustrates an example of a fully enclosed pot core integrated planar structure according to some embodiments. Referring to FIG. 6A, an inductor air gap 620 can be encapsulated within a magnetic material 610 to minimize stray magnetic fields. FIG. 6A illustrates an example of a fully enclosed pot core integrated planar structure 600 according to some embodiments. The enclosed pot core integrated planar structure 600 of FIG. 6A does not include a flux shaping plate. In some embodiments, the enclosed pot core integrated planar structure 600 can include an inductor portion 630 and a transformer portion 640. The inductor portion 630 can have an EE structure that can include a first side 632, a second side 634, and a core center post 636. In some examples, the core center post 636 can be disposed between the first side 632 and the second side 634. In some examples, the first side 632 and the second side 634 can surround the center post 636. In some embodiments, the first side 632 can include several layers of the primary winding 638A (e.g., a first portion of the primary winding), and the second side 634 can include several layers of the secondary winding 638B (e.g., a first portion of the secondary winding). The present disclosure is not limited to the number of layers of each primary winding and secondary winding described above and shown in FIG. 6A . In some embodiments, the first side 632 can include a first portion of the primary winding 638A, and the second side 634 can include a first portion of the secondary winding 638B. The transformer portion 640 can include a second portion of the primary winding 638C and a second portion of the secondary winding 638D. In some embodiments, the second portion of the primary winding 638C and the second portion of the secondary winding 638D can be positioned perpendicular to each other. For example, the primary winding can surround the inductor portion 630 and the transformer portion 640, as described below in FIG. 6D . A first portion of the primary winding can be disposed in the inductor portion 630 (e.g., the first side 632), and a second portion of the primary winding can be disposed in the transformer portion 640. Further, the secondary winding can surround the transformer portion 640.In this integrated planar structure (e.g., transformer portion 640 and inductor portion 630 can be integrated), a first portion of the secondary winding can be disposed in inductor portion 630 (e.g., second side 634), and a second portion of the secondary winding can be disposed in transformer portion 640. In some embodiments, one or more posts 650 can be interposed between top core 610A and bottom core 610B. For example, as shown in FIG. 6A , posts 650, 650A can be interposed between top cores 610A and 610B. As further shown in FIG. 6A , at least one post (e.g., post 650A) of the one or more posts 650 can be shared between inductor portion 630 and transformer portion 640.

[0087] As shown in FIG. 6A, the magnetic body 610 can include a top core 610A and a bottom core 610B. The inductor portion 630 and the transformer portion 640 can be surrounded by the top core 610A, the bottom core 610B, and a post 650 (shown in FIG. 6B). In some embodiments, the inductor portion 630, the transformer portion 640, the center post 636, and another post (650 shown in FIG. 6B) can be vertically positioned on top of the bottom core 610B and below the top core 610A.

[0088] FIG. 6B shows a comparison diagram comparing a conventional discrete transformer / inductor structure 500 with an integrated transformer 600. Referring to FIG. 6B, the discrete transformer / inductor structure 500 can include discrete components: a transformer 502 and an inductor 504. As shown in FIG. 6B, the discrete transformer / inductor structure 500 can include three windings, while the integrated transformer 600 can include two windings because the inductor winding can be shared with the primary winding of the transformer portion of the integrated transformer 600. Furthermore, the discrete transformer / inductor structure 500 can include six core posts (e.g., core posts 550, 550A, and 550B), while the integrated transformer 600 can include four core posts (e.g., core posts 650 and 650A) because a shared core post (e.g., 650A) can be used between the inductor portion 630 and the transformer portion 640 in the integrated transformer 600. Thus, the integrated transformer 600 can be manufactured more cost-effectively and operate more efficiently than the discrete transformer / inductor structure 500 .

[0089] FIG. 6C illustrates another example of a fully enclosed pot core integrated planar structure 650 according to some embodiments. Referring to FIG. 6C, an inductor air gap 620 can be encapsulated within the magnetic material 610 to minimize stray magnetic fields. The enclosed pot core integrated planar structure 650 of FIG. 6B can include a flux shaping plate 670 disposed on the center post 660. The enclosed pot core integrated planar structure 650 of FIG. 6C can also include the flux shaping plate 670. In some embodiments, the enclosed pot core integrated planar structure 650 can include an inductor portion 630 and a transformer portion 640. The inductor portion 630 can have an EE structure that can include a first side 632, a second side 634, and a core center post 660. In some examples, the core center post 660 can be disposed between the first side 632 and the second side 634. In some examples, the first side 632 and the second side 634 surround the center post 636. In some embodiments, the first side 632 can include a first portion of the primary winding 638A in several layers, and the second side 634 can include a first portion of the secondary winding 638B in several layers. However, the present disclosure is not limited to the number of layers of each primary and secondary winding described above and illustrated in FIG. 6C . In some embodiments, the transformer portion 640 can include a second portion of the primary winding 638C and a second portion of the secondary winding 638D. In some embodiments, the second portion of the primary winding 638C and the second portion of the secondary winding 638D can be positioned perpendicular to each other. In some embodiments, the inductor portion 630 can include a flux shaping plate 670. The flux shaping plate 670 can be positioned on top of the core center post 660. In some examples, the width of the flux shaping plate 670 can be greater than the width of the core center post 660. In some embodiments, an air gap 620 can be formed between the top of the flux shaping plate 670 and the magnetic material 610. In some examples, a symmetrical air gap can be formed on the first side 632 and the second side 634. In some embodiments, one or more posts 650 can be interposed between the top core 610A and the bottom core 610B.For example, as shown in Figure 6A, posts 650, 650A can be interposed between top cores 610A and 610B. As further shown in Figure 6A, at least one post (e.g., post 650A) of the one or more posts 650 can be shared between inductor portion 630 and transformer portion 640.

[0090] 6D is a perspective view of the fully enclosed pot core integrated planar structure of FIG. 6A or 6C, according to some embodiments. Although not shown in FIG. 6D, the fully enclosed pot core integrated planar structure of FIG. 6D can include a flux forming plate.

[0091] As shown in FIG. 6D , in some embodiments, at least one of the sealed pot core monolithic planar structures 600 or 650 ( FIG. 6D shows an example of a monolithic planar structure 600) can include an inductor portion (side) 630 and a transformer portion (side) 640, which can be integrated into the single structure 600 to have shared windings (e.g., primary winding 638A and secondary winding 638B). The windings 638A, 638B of the inductor portion 630 and the transformer portion 640 can at least partially overlap each other vertically. For example, in the inductor portion 630, the primary winding 638A and the secondary winding 638B can overlap at portion 639A. Also, in the transformer portion 640, the primary winding 638A and the secondary winding 638B can overlap at portion 639B. In some embodiments, portions of the primary winding 638A and portions of the secondary winding 638B can be stacked together in portion 639B such that portions of the primary winding 638A can be sandwiched between two layers of portions of the secondary winding 638B. In some embodiments, each of the primary winding 638A and the primary winding 638B can function as an inductor, and the combination of the primary winding and the secondary winding 638A can function as a transformer. In these embodiments, at least a portion of the primary winding 638A can be disposed below or above the secondary winding 638B such that at least a portion of the primary winding 638A vertically overlaps the secondary winding 638B (see, for example, FIG. 6D ). In some embodiments, the secondary winding 638B can function as an inductor, and the combination of the primary winding 638A and the secondary winding 638B can function as a transformer. In these embodiments, at least a portion of the secondary winding 638B can be disposed below or above the primary winding such that at least a portion of the secondary winding 638B vertically overlaps the primary winding 638A. The discussion in this paragraph is applicable to at least the embodiments shown in Figures 7A, 7B, 8A, 8C, 8D, 12B-12E, or 13A-13C. Note that Figure 11 shows that at least a portion of the flux shaping plate vertically overlaps both the primary and secondary windings, and that the primary and secondary windings do not overlap each other.

[0092] Figure 6E illustrates the near field of the EE core and pot core structures shown in Figures 6A and 6C, respectively, according to some embodiments. Referring to Figure 6E, the enclosed pot core structure (shown at the bottom of Figure 6E) can provide near field reduction compared to conventional inductor and transformer structures.

[0093] Figure 6F shows the current density distribution of the closed pot core structure 600 without flux shaping (or flux shaping plates). Figure 6G shows the improved current density distribution leading to minimized winding loss distribution of the closed pot core structure 650 that can include flux shaping (or flux shaping plates). Referring to Figures 6F and 6G, the closed pot core structure with flux shaping plates can reduce winding losses. Table 1 shows the core loss and conduction loss of the linear guide post structure 600 and the integrated planar structure 650 with flux shaping. [Table 1]

[0094] 7A and 7B illustrate exemplary hybrid pot core integrated planar structures 700 and 750 according to some embodiments. The hybrid pot core integrated planar structures 700 and 750 can have a closed pot core structure on the inductor side and an open EE or EI structure on the transformer side. FIG. 7A illustrates an exemplary hybrid pot core integrated planar structure 700 according to some embodiments. The hybrid pot core integrated planar structure 700 can include a flux shaping plate 670.

[0095] In some embodiments, as shown in the hybrid pot core integrated planar structure 700 of FIG. 7A , the height of the transformer 640 can be reduced, resulting in the height of the transformer portion 640 being lower than the height of the inductor portion 630. For example, each inductor portion 630 and transformer portion 640 can include an inductor portion top core 610CC and a transformer portion top core 610AA, respectively. The transformer top core 610AA can be positioned lower than the inductor top core 610CC. The hybrid pot core integrated planar structure 700 of FIG. 7A can include a flux shaping plate 670. In some embodiments, the sealed pot core integrated planar structure 650 can include the inductor portion 630 and the transformer portion 640. The inductor portion 630 can have an EE structure that can include a first side 632, a second side 634, and a core center post 660. In some examples, the core center post 660 can be positioned between the first side 632 and the second side 634. In some examples, the first side 632 and the second side 634 may surround the center post 636. In some embodiments, the first side 632 may include a first portion of the primary winding 638A in several layers, and the second side 634 may include a first portion of the secondary winding 638B in several layers. This disclosure is not limited to the number of layers of each primary winding and secondary winding described above and shown in FIG. 7A . In some embodiments, the transformer portion 640 may include a second portion of the primary winding 638C and a second portion of the secondary winding 638D. In some embodiments, the second portion of the primary winding 638C and the second portion of the secondary winding 638D may be vertically arranged. In some embodiments, the inductor portion 630 may include a flux shaping plate 670. The flux shaping plate 670 may be disposed on top of the core center post 660. In some examples, the width of the flux shaping plate 670 may be greater than the width of the core center post 660. In some embodiments, an air gap 620 can be formed between the top of the flux shaping plate 670 and the magnetic material 610 .In some embodiments, the inductor portion 630, the transformer portion 640, the center post 660, and other posts (650 shown in FIG. 6B ) can be vertically positioned on top of the bottom core 610B and below the top cores 610A and 610C. In some embodiments, one or more posts 650A-650C can be interposed between the top cores 610AA / 610CC and the bottom core 610B. For example, as shown in FIG. 7A , the post 650B can be interposed between the top cores 610AA and 610B. Furthermore, the posts 650A and 650C can be interposed between the top core 610CC and the bottom core 610B of the inductor portion 630. As further shown in FIG. 6A , the post 650A can be shared between the inductor portion 630 and the transformer portion 640.

[0096] FIG. 7B illustrates another example of a hybrid pot core integrated planar structure 750 according to some embodiments. The hybrid pot core integrated planar structure 750 can be formed from the exemplary hybrid pot core integrated planar structure 700. For example, the hybrid pot core integrated planar structure 750 can be formed from the hybrid pot core integrated planar structure 700 by removing the post 650B (shown in FIG. 7A) and the top core of the transformer section 610AA (shown in FIG. 7A) and resizing the bottom core 610B to the width of the top core 610CC of the inductor section 630. As further shown in FIG. 7B, the hybrid pot core integrated planar structure 750 can include a flux shaping plate 670 on top of the center post 660. These hybrid structures 700 and 750 can minimize the weight / cost of the transformer core while minimizing near-field impact.

[0097] FIG. 8A illustrates the concept of core lamination to minimize eddy currents. For example, without splitting, eddy current core loss for a single core can be 1.8 times greater than a design with two splits. Meanwhile, with one split, core loss can be 1.4 times greater than a design with two splits. The core split shown in FIG. 8A is merely an example, and the present disclosure is not limited thereto. For example, three or more splits (four or more cores) may also be possible.

[0098] Figure 8B shows an example structure 800 for improving magnetic flux density sharing in split cores by dominating the reluctance of each split core using an air gap on the center post, according to some embodiments. Figure 8C shows an example structure 850 for improving magnetic flux density sharing in split cores by using consistent bondline thickness control, according to some embodiments. The example structures 800 and 850 of Figures 8B and 8C can minimize magnetic flux density sharing issues in split core structures.

[0099] In some embodiments, as shown in FIG. 8B , the post 650A shared between the transformer portion 640 and the inductor portion 630 of the monolithic planar structure 800 of FIG. 8B can include a flux-forming air gap 810. The monolithic planar structure 800 of FIG. 8B can include a flux-forming plate 670. In some embodiments, the sealed pot-core monolithic planar structure 650 can include the inductor portion 630 and the transformer portion 640. The inductor portion 630 can have an EE structure that can include a first side 632, a second side 634, and a core center post 660. In some examples, the core center post 660 can be disposed between the first side 632 and the second side 634. In some examples, the first side 632 and the second side 634 can surround the center post 636. In some embodiments, the first side 632 can include a first portion of the primary winding 638A with several layers, and the second side 634 can include a first portion of the secondary winding 638B with several layers. This disclosure is not limited to a specific number of layers per primary and secondary winding. The transformer portion 640 can include a second portion of the primary winding 638C and a second portion of the secondary winding 638D. In some embodiments, the inductor portion 630 can include a flux shaping plate 670. In some embodiments, the second portion of the primary winding 638C and the second portion of the secondary winding 638D can be vertically arranged. The flux shaping plate 670 can be disposed on top of the core center post 660. In some examples, the width of the flux shaping plate 670 can be greater than the width of the core center post 660. In some embodiments, an air gap 620 can be filled between the top of the flux shaping plate 670 and the magnetic material 610. In some embodiments, as depicted in Figure 8C, posts 650 and 650A can include a flux-shaping air gap 810. In some embodiments, as depicted in Figure 8D, a transformer portion 840 can be interposed between two portions 830A, 830B of inductor portion 830.8D, post 850A can be shared between a portion of inductor portion 830A and transformer portion 840, and between another portion of inductor portion 830B and transformer portion 840. In some embodiments, as further described in FIG. 8D, each of posts 850A and 850B can include an air gap 855.

[0100] FIG. 9A illustrates a conventional high-current termination for a planar magnetic with wire windings. FIG. 9A illustrates conventional complex wire soldering for wire windings. FIG. 9B illustrates a conventional high-current termination for a planar magnetic with busbar windings. FIG. 9B illustrates a dangerous bolted joint for busbar windings. FIGs. 9C and 9D illustrate exemplary low-loss PCB winding terminations according to some embodiments. For example, the structures of FIGS. 9C and 9D allow the terminals 950 to be integrated into part of the PCB winding, simplifying the manufacturing process and reducing excess losses (e.g., soldering) from the termination. The structures of FIGS. 9C and 9D allow the input and output terminals to overlap at 930, reducing AC winding losses at high frequencies due to stray field cancellation.

[0101] Figure 10A shows side-by-side winding terminations (in and out). Figure 10B shows overlapped winding terminations (in and out) according to some embodiments. The overlapped winding terminations shown in Figure 10B can significantly reduce current density hot spots and reduce AC winding losses.

[0102] 11A and 11B illustrate a fully enclosed pot core integrated planar structure 1100 according to some embodiments. FIGS. 11A and 11B can include two inductor portions 630A and 630B (e.g., inductor portion 630 shown in FIG. 6C ). For example, inductor portions 630A and 630B can be integrated into structure 1100 by sharing post 950A. FIG. 11A is a side view of fully enclosed pot core integrated planar structure 1100. FIG. 11B is a perspective view of fully enclosed pot core integrated planar structure 1100. In these embodiments, primary winding 1160 and secondary winding 1150 can be stacked side by side within a PCB, rather than stacked vertically on top of each other. An integrated inductor can be formed by the air gap between the two windings of this structure and the core post (with or without a flux shaping plate). For example, as shown in FIG. 11B, secondary winding 1150 can surround post 950A, such as secondary winding 1150 shown in FIG. 11B. Primary winding 1160 can surround core posts 1170A and 1170B of each inductor portion 630A and 630B, respectively. Thus, primary winding 1160 can be formed as shown in FIG. 11B. The number of PCB layers may be minimal with this structure given the required number of turns.

[0103] 12A-12E show various examples of open EE three-leg structures with and without flux shaping, according to some embodiments. As shown in FIG. 12A, the open EE three-leg structure 1200 can include a flux-shaping air gap in the top core, while the open EE three-leg structure 1250 can include a non-flux-shaping air gap on the side between the bottom and top cores. While FIGS. 12B-12E show that the secondary winding can be located above the primary winding, the present disclosure is not limited thereto. For example, the primary winding may be located above the secondary winding. Again, an integrated inductor and transformer design allows for reduced size, and the flux-shaping air gap can reduce winding losses. Inductive losses in the heat sink can be a strong function of stray magnetic fields, as shown in FIG. 12F.

[0104] As shown in FIG. 12A, the open EE three-leg structure 1200 can include three legs 1210A-1210C arranged perpendicular to a bottom core 1220. As shown in FIG. 12B, the primary winding 1230 can surround leg 1210B (e.g., the center leg). Additionally, the secondary winding 1240 can surround leg 1210C (e.g., the side leg). As further shown in FIG. 12C, a top core 1250 can be disposed on top of the center leg 1210B and the side leg 1210C. In some embodiments, a flux-shaping air gap 1260 can be formed in a portion of the primary winding 1230 that may not be covered by the top core 1250.

[0105] The open EE three-leg structure 1200 can be modified as shown in Figures 12D and 12E. For example, as shown in Figure 12D, three legs (e.g., a first lateral leg 1210A, a middle leg 1210B, and a second lateral leg 1210C) can be formed between a top core 1250 and a bottom core 1220. An air gap 1250A can be formed in the top core 1250 between the first lateral leg 1210A and the middle leg 1210B. Furthermore, the primary winding 1230 can be formed by surrounding the middle leg 1210B, and the secondary winding 1240 can be formed by surrounding the second lateral leg 1210C.

[0106] FIG. 12E shows another example of an open EE three-leg structure 1200. For example, as shown in FIG. 12D, three legs (e.g., a first lateral leg 1210A, a middle leg 1210B, and a second lateral leg 1210C) can be formed between a top core 1250 and a bottom core 1220. An air gap 1250B can be formed on the first lateral leg 1210A (e.g., between the top core 1250 and the bottom core 1220). Furthermore, the primary winding 1230 can be formed by surrounding the middle leg 1210B, and the secondary winding 1240 can be formed by surrounding the second lateral leg 1210C.

[0107] FIG. 13A illustrates an open EE four-leg structure 1300A without flux shaping, according to some embodiments. The open EE four-leg structure 1300A has a lower stray field compared to a three-leg EE core structure, which can minimize pedestal / heat sink losses and therefore may be ideal for designs with heat sinks. In some embodiments, the open EE four-leg structure 1300A can include first through fourth legs 1310A through 1310D, respectively. These four legs 1310A through 1310D can be interposed between a top core 1350 and a bottom core 1320. In some examples, the primary winding 1330 can surround the second leg 1310B, and the secondary winding 1340 can surround the third leg 1310C. In some embodiments, the secondary winding 1340 can be placed on top of the primary winding 1330. In some applications, the secondary winding 1340 may also be positioned below the primary winding 1330. As further shown in FIG. 13A , a first air gap may be formed in the first leg 1310A, and a second air gap 1350B may be formed in the fourth leg 1310D. In some examples, the open EE4-leg structure 1300A may have a symmetrical design relative to a center 1360 of the open EE4-leg structure 1300A.

[0108] FIG. 13B illustrates an open EE four-leg structure 1300B with flux shaping and two or more symmetric air gaps, according to some embodiments. The open EE four-leg structure 1300B can further reduce winding losses due to the flux shaping air gaps. In some embodiments, the open EE four-leg structure 1300B can include first through fourth legs 1310A through 1310D, respectively. These four legs 1310A through 1310D can be interposed between a top core 1350 and a bottom core 1320. In some examples, the primary winding 1330 can surround the second leg 1310B, and the secondary winding 1340 can surround the third leg 1310C. In some embodiments, the secondary winding 1340 can be positioned on top of the primary winding 1330. In some applications, the secondary winding 1340 can also be positioned below the primary winding 1330. 13B, a first air gap 1350C can be formed on the top core 1350 between the first leg 1310A and the second leg 1310B. A second air gap 1350D can be formed on the top core 1350 between the third leg 1310C and the fourth leg 1310D. In some examples, the open EE4-leg structure 1300B can have a symmetrical design relative to the center 1360 of the open EE4-leg structure 1300A.

[0109] FIG. 13C illustrates an open EE four-leg structure 1300C with flux shaping and two or more asymmetric air gaps, according to some embodiments. The open EE four-leg structure 1300C can allow design flexibility with asymmetric resonant inductances in the primary and secondary windings. In some examples, the primary winding 1330 can surround the second leg 1310B, and the secondary winding 1340 can surround the third leg 1310C. In some embodiments, the secondary winding 1340 can be located on top of the primary winding 1330. In some applications, the secondary winding 1340 can also be located below the primary winding 1330. As further shown in FIG. 13B, a first air gap 1350E can be formed on the top core 1350 between the first leg 1310A and the second leg 1310F. A second air gap 1350D can be formed on the top core 1350 between the third leg 1310C and the fourth leg 1310D. In some examples, the air gaps 1350E and 1350F can be formed symmetrically about the center 1360 of the open EE4-leg structure 1300A.

[0110] 14 is a diagram illustrating near-field reduction in an open EE core structure with a metal shield, according to some embodiments. Open EE core structures can have large stray magnetic fields that can be problematic for EMC. As can be seen in FIG. 14, an open EE core structure with a metal shield can substantially reduce the near-field.

[0111] FIG. 15A illustrates an example of an EE core structure 1500 with a metal shield 1530 according to some embodiments. In the open EE core structure 1500, the metal shield 1530 can contact the heat sink 1510 at all points. For example, the open EE core structure 1500 can include features that can be pressed to ensure contact with the heat sink surface 1510 and have multiple small sections to ensure coplanarity with the heat sink 1510 and bottom core 1520. In some embodiments, a wall 1540 can be positioned on top of the heat sink 1510 to compensate for any different heights between the bottom core 1520 and the heat sink 1510. As shown in FIG. 15B, the metal shield 1530 can include multiple small sections of notches.

[0112] 15C illustrates another example of an EE core structure 1550 with a metal shield 1530, according to some embodiments. The open EE core structure 1550 can include one or more walls extending from the heat sink 1510, and the metal shield 1530 can be positioned to overlap, for example, horizontally, with the wall 1540. The open EE core structure 1550 can tolerate flexibility with imperfect contact between the metal shield 1530 and the bottom of the heat sink 1510.

[0113] FIGS. 16A-16D illustrate the concept of a partially interleaved winding structure between two stages (stage A and stage B). FIG. 16C illustrates a winding structure without winding interleaving between two stages. FIG. 16D illustrates a partially interleaved winding structure with winding interleaving between two stages according to some embodiments. According to the embodiment of FIG. 16D, both the cover and heat sink widths may be reduced by approximately 12%. This is merely an example; in some embodiments, the widths may be reduced by more than approximately 12%. Furthermore, due to the de-overlap of stray magnetic fields, the induced current density at the intermediate pedestal can be reduced. FIG. 16E illustrates an example induced current density distribution for the winding structure without winding interleaving between two stages shown in FIG. 16C. FIG. 16F illustrates an example induced current density distribution for the partially interleaved winding with winding interleaving between two stages shown in FIG. 16D. Table 2 below shows the inductive losses in the heat sink for the partially interleaved windings, which are lower than the winding configuration without winding interleaving. [Table 2]

[0114] It should be understood that features, materials, properties, or groups described in connection with a particular aspect, embodiment, or example are applicable to any other aspect, embodiment, or example described in this section or elsewhere in this specification, unless there is a contradiction therein. All features disclosed in this specification (including any accompanying claims, abstract, and drawings), and / or all steps of any method or process so disclosed, may be combined in any combination, except combinations in which at least some of such features and / or steps are mutually exclusive. Protection is not limited to the details of any foregoing embodiment. Protection extends to any novel, or any novel combination of, features disclosed in this specification (including any accompanying claims, abstract, and drawings), or any novel, or any novel combination of steps of any method or process so disclosed.

[0115] Furthermore, certain features that are described in this disclosure in the context of separate embodiments can also be implemented in combination in a single embodiment. Conversely, various features that are described in the context of a single embodiment can also be implemented in multiple embodiments separately or in any suitable subcombination. Furthermore, while features may be described above as acting in a particular combination, one or more features from a claimed combination can, in some cases, be deleted from the combination, and the combination can be claimed as a subcombination or a variation of the subcombination.

[0116] Furthermore, while operations may be illustrated in the figures or described herein in a particular order, such operations need not be performed in the particular order illustrated, or in sequential order, or even all operations need to be performed to achieve desirable results. Other operations not shown or described may be incorporated into the example methods and processes. For example, one or more additional operations may be performed before, after, simultaneously with, or between any of the described operations. Furthermore, operations may be rearranged or reordered in other implementations. Those skilled in the art will appreciate that in some embodiments, the actual steps performed in the illustrated and / or disclosed processes may differ from those shown in the figures. Depending on the implementation, certain of the steps described above may be omitted, and other steps may be added. Furthermore, the features and attributes of the specific embodiments disclosed above may be combined in different ways to form additional embodiments, all of which are within the scope of the present disclosure. Also, the separation of various system components in the above implementations should not be understood to require such separation in all implementations, and it should be understood that the described components and systems may generally be integrated together in a single product or packaged in multiple products. For example, any of the components of the energy storage systems described herein may be provided separately or may be integrated (e.g., packaged together or attached together) to form an energy storage system.

[0117] For purposes of this disclosure, certain aspects, advantages, and novel features have been described herein. Not necessarily all such advantages may be achieved in accordance with any particular embodiment. Thus, for example, one skilled in the art will recognize that the present disclosure may be embodied or carried out in a manner that achieves one advantage or advantages as taught herein, without necessarily achieving other advantages that may be taught or suggested herein.

[0118] Conditional language such as "can," "could," "might," or "may," unless specifically stated otherwise or understood otherwise in the context in which it is used, is generally intended to convey that certain embodiments include certain features, elements, and / or steps, while other embodiments do not. Thus, such conditional language is not generally intended to imply that features, elements, and / or steps are required in any way in one or more embodiments, or that one or more embodiments necessarily include logic for determining whether those features, elements, and / or steps are included in or performed in any particular embodiment, with or without user input or prompting.

[0119] Conjunctions such as the phrase "at least one of X, Y, and Z" are understood differently to convey that, unless specifically stated otherwise, in the context of common usage, the item, term, etc. can be either X, Y, or Z. Thus, such conjunctive language is not generally intended to imply that a particular embodiment requires the presence of at least one of X, at least one of Y, and at least one of Z.

[0120] As used herein, language of degree, such as "approximately," "about," "generally," and "substantially," denotes a value, amount, or characteristic that approaches a stated value, amount, or characteristic that still performs a desired function or achieves a desired result.

[0121] The scope of the present disclosure is not intended to be limited by the specific disclosure of embodiments in this section or elsewhere herein, but may be defined by the claims, as presented in this section or elsewhere herein, or as presented in the future. Claim language should be interpreted broadly based on the language employed in the claims, and not limited to the examples described herein or during prosecution of the application, and examples should be construed as non-exclusive.

[0122] While specific embodiments have been described, these embodiments are presented by way of example only and are not intended to limit the scope of the present disclosure. Indeed, the novel methods and systems described herein may be embodied in a variety of other forms. Furthermore, various omissions, substitutions, and modifications may be made in the systems and methods described herein without departing from the spirit of the present disclosure. The appended claims and their equivalents are intended to cover such forms or modifications as fall within the scope and spirit of the present disclosure. Accordingly, the scope of the present invention is defined solely by reference to the appended claims. [Prior art documents] [Non-patent literature]

[0123] [Non-Patent Document 1] M.D´Antonio,S.Chakraborty and A.Khaligh,”Planar Transformer With Asymmetric Integrated Leakage Inductance Using Horizontal Air Gap,” in IEEE Transactions on Power Electronics,vol.36,no.12,pp.14014-14028,Dec.2021,doi:10.1109 / TPEL.2021.3089606.”

Claims

1. 1. An integrated magnetic structure comprising: Top core and A bottom core; one or more posts interposed between the top core and the bottom core; an inductor portion comprising a center post, a first portion of a primary winding, and a first portion of a secondary winding, the center post being different from and spaced apart from the one or more posts; a transformer integrated with the inductor portion by sharing a post of the one or more posts; 1. An integrated magnetic structure comprising:

2. The integrated magnetic structure of claim 1 , wherein the transformer includes a second portion of the primary winding and a second portion of the secondary winding.

4. 3. The integrated magnetic structure of claim 2, wherein the second portion of the primary winding and the second portion of the secondary winding vertically overlap one another.

4. The integrated magnetic structure of claim 1, wherein the primary winding surrounds the secondary winding.

5. The integrated magnetic structure of claim 1 , wherein at least one of the primary winding or the secondary winding comprises an interleaved winding structure.

6. The integrated magnetic structure of claim 1 , wherein the center post is disposed perpendicular to a center position of the bottom core of the inductor portion.

7. The integrated magnetic structure of claim 1 , wherein the one or more posts, the transformer, the inductor portion, and the center post are disposed within a completely enclosed housing.

8. The integrated magnetic structure of claim 1 , wherein a flux-forming air gap is formed in each of the one or more posts and the center post.

9. 9. The integrated magnetic structure of claim 1, wherein a flux-forming air gap is formed on the center post.

10. 10. The integrated magnetic structure of claim 1, wherein the inductor portion has two or more symmetrical air gaps formed therein.

11. 11. The integrated magnetic structure of claim 1, further comprising a metallic shielding plate disposed adjacent the one or more posts and configured to at least partially shield stray magnetic fields.

12. 1. An integrated magnetic structure comprising: Top core and A bottom core; one or more posts interposed between the top core and the bottom core; an inductor portion including a center post and a flux shaping plate disposed on top of the center post; a transformer integrated with the inductor portion by sharing a post of the one or more posts; 1. An integrated magnetic structure comprising:

13. 13. The integrated magnetic structure of claim 12, wherein the inductor portion further includes a first portion of a primary winding and a first portion of a secondary winding, and the transformer includes a second portion of the primary winding and a second portion of the secondary winding.

14. The integrated magnetic structure of claim 13 , wherein the primary winding is configured to surround the secondary winding.

15. 15. The integrated magnetic structure of claim 13 or 14, wherein the second portion of the primary winding and the second portion of the secondary winding vertically overlap each other.

16. 16. The integrated magnetic structure of claim 12, wherein a flux-forming air gap is formed in each of the one or more posts and the center post.

17. 16. The integrated magnetic structure of claim 12, wherein a flux-forming air gap is formed on the center post.

18. 1. An integrated magnetic structure comprising: a top core including a first portion and a second portion, the first portion and the second portion of the top core having different heights and being disposed at different levels; A bottom core; one or more posts interposed between the top core and the bottom core; an inductor portion comprising a center post, a first portion of a primary winding, and a first portion of a secondary winding, the center post being different from and spaced apart from the one or more posts; a transformer disposed between the second portion of the top core and the bottom core, the transformer including a second portion of the primary winding and a second portion of the secondary winding; 1. An integrated magnetic structure comprising:

19. 20. The integrated magnetic structure of claim 18, wherein a flux-forming air gap is formed in each post of the one or more posts and the center post.

20. 20. The integrated magnetic structure of claim 18, wherein a flux-forming air gap is formed on the center post.

21. 21. The integrated magnetic structure of claim 18, wherein a first portion of the top core is disposed on top of the transformer and the second portion of the top core is disposed on top of the inductor portion.

Images