Integrated power supply using planar energy transfer elements

Abstract

A power converter includes a circuit layer stack, a magnetic core, a region of the circuit layer stack, and a power converter circuit component mounted on the circuit layer stack. The circuit layer stack has an aperture extending through each circuit layer. A portion of the circuit layer forms an energy transfer element including an input winding and an output winding. Each winding comprises at least one winding layer having a planar winding and a connection for electrical connection. A magnetic core is positioned within the bore substantially perpendicular to the stack. The region of the stack of circuit layers includes the windings and connections for electrical connection of the input windings and the output windings. Power converter circuit components are mounted within the region of the stack and outside the magnetic core.

Description

Technical Field

[0001] The present disclosure generally relates to power converters, and more particularly, to packaging of power converters. Background Art

[0002] Power utilities transmit unregulated alternating current (ac), which conveys electrical signals across long distances and between buildings. This transmission requires very high voltages that most circuits within homes and businesses (e.g., electronic devices) cannot handle. The voltage needs to be reduced for use in those environments. Similarly, high-voltage batteries are used to power the motors of electric vehicles. The voltage output of the battery needs to be reduced to power internal accessories (e.g., windows, radios, and navigation systems). Switch-mode power converters, also known as switching power converters, are commonly used to provide lower voltages for many of today's electronic devices due to their high efficiency, small size, and low weight. A switch-mode power converter converts a high voltage associated with an unregulated ac input into a lower voltage associated with a constant or stable direct current (dc) output (also known as a regulated dc output) through an energy transfer element (e.g., a transformer). A switch-mode power converter typically provides dc output regulation by sensing one or more signals representative of one or more output quantities (e.g., voltage, current, or a combination of both) and controlling the output in a closed loop. In operation, switches are turned on and off by changing the duty cycle, switching frequency, or the number of pulses of the switch per unit time in the switch-mode power converter to provide a desired output.

[0003] Power converters typically include one or more controllers that sense the output of the power converter and control the operation of the switches to regulate the output. These controllers typically require a regulated or unregulated voltage source to power the circuit components of the controller. Brief Description of the Drawings

[0004] Non-limiting and non-exhaustive embodiments of the present invention are described with reference to the following drawings, in which like reference numerals refer to like parts throughout the various views unless otherwise specified. In all several views of the drawings, corresponding reference characters indicate corresponding components.

[0005] Figure 1 A circuit schematic diagram of circuit components for a direct current (dc)-to-dc power converter 30 in accordance with the present disclosure is illustrated.

[0006] Figure 2 is Figure 1A top-down exemplary view of the layout of the DC-DC power converter 30 shown in the figure, which illustrates that the controller 32 and the power circuit components are illustratively positioned within the region 38c of the planar energy transfer element 38 and outside the magnetic core assembly 48.

[0007] Figures 3A - 3B Illustrates a power converter assembly having a two-piece E-E or E-I shaped magnetic core. Figure 3A Illustrates a perspective view. Figure 3B Illustrates a side view.

[0008] Figure 4 is Figure 3A and Figure 3B the exploded view of the power converter assembly shown in the figure.

[0009] Figure 5 is the exploded view of the electrical connection layer and the winding layer showing a simplified stack of the circuit layer 46.

[0010] In all of the several views of the drawings, corresponding reference characters indicate corresponding parts. Those skilled in the art will understand that the elements in the drawings are illustrated for simplicity and clarity and are not necessarily drawn to scale. For example, the dimensions of some elements in the drawings may be exaggerated relative to other elements to help improve the understanding of the various embodiments of the present invention. In addition, commonly understood elements that are useful or necessary in a commercially viable embodiment are generally not depicted so as not to unduly obscure the view of these various embodiments of the present invention. Detailed Description

[0011] Conventional power converters include energy transfer elements, such as discrete transformers having an input winding and an output winding. Discrete transformers are typically mounted on a printed circuit board. To minimize EMI and parasitic noise from resistance, inductance, and capacitance, the transformer and any other power converter circuit components are physically separated from each other.

[0012] The disclosed embodiments relate to a DC-DC power converter having power circuit components mounted on a circuit layer stack that includes planar energy transfer elements, such as planar transformers. Holes extend through each of the circuit layers. A magnetic core assembly is positioned within the holes. A portion of the circuit layer stack includes an input winding layer and an output winding layer. Each winding layer includes windings and connectors for electrical connection. The power converter circuit components include input circuit components and output circuit components mounted within a region of the stack and external to the magnetic core. The region of the stack includes the windings and connectors for electrical connection of the larger of the input winding layer and the output winding layer. In one embodiment, the input circuit components may be mounted on the circuit layer stack and electrically connected to the input winding layer. In one embodiment, the output circuit components may be mounted on the circuit layer stack and electrically connected to the output winding layer.

[0013] Figure 1 A circuit schematic of the circuit components of a DC-DC power converter 30 in accordance with the present disclosure is illustrated. A controller 32 is connected to additional power converter components that include a power switch 35, a synchronous rectifier 34, and a planar energy transfer element 38 (e.g., a planar transformer), a filter circuit 40, a sensing circuit 42, and a feedback circuit 44. The planar energy transfer element 38 is integrated within a circuit layer stack 46. When the planar energy transfer element 38 is a transformer, the input winding 38a is the primary winding and the output winding 38b is the secondary winding. Each of the windings includes at least one winding layer. The controller 32 and the additional power converter circuit components are positioned on the stack 46 such that they are within a region 38c ( Figure 2 as seen in) of the circuit layer stack 46. The region 38c of the circuit layer stack 46 includes the windings and connectors for electrical connection of the larger of the input winding 38a and the output winding 38b. An embodiment of the converter 30 may optionally form part of an AC-DC converter, where a bridge rectifier and an input capacitor (shown in gray in block 16) are added, as would be understood by one of ordinary skill in the art.

[0014] Figure 2 is Figure 1Top-down exemplary view of the layout of the DC-DC power converter 30 shown in FIG. This view illustrates that the controller 32 and additional power circuit components (e.g., power switch 35, synchronous rectifier 34, filter circuit 40, sensing circuit 42, and feedback circuit 44) are illustratively positioned within the region 38c of the planar energy transfer element 38 and outside the core assembly 48. The core assembly 48 extends through the circuit layer stack 46. The power converter circuit components may be positioned on one of the first surface 46a or the second surface 46b of the circuit layer stack 46, or on both the first surface 46a and the second surface 46b. The first surface and the second surface are parallel to the circuit layers. An optional housing (not shown) may surround the circuit layer stack 46, the core assembly 48, and the power converter circuit components.

[0015] The circuit layer stack 46 has holes extending through each circuit layer. A portion of the circuit layer stack 46 and the core assembly 48 form a planar energy transfer element 38, e.g., a planar transformer. The portion of the circuit layer stack 46 includes an input winding 38a and an output winding 38b. Each winding includes at least one winding layer. The winding layer includes a planar winding and connectors for electrical connection. The planar winding may be a circular spiral or an elliptical spiral having one or more turns. The core assembly 48 is positioned within the holes substantially perpendicular to the circuit layer stack 46. The region 38c of the planar energy transfer element 38 is coplanar with the first surface and includes the windings and connectors for electrical connection of the input winding layer 38a and the output winding layer 38b.

[0016] The controller 32, the input winding 38a, and the output winding 38b are electrically connected to the power converter circuit components. The controller 32 facilitates communication between the input side and the output side of the power converter.

[0017] The power converter circuit components are input circuit components or output circuit components. In this embodiment, the power converter circuit components are mounted on the first surface 46a. A portion of the first surface 46a has been removed to show a layer including one layer of the input winding 38a. The input circuit components are mounted within the region 38c of the input winding 38a and the output winding 38b and outside the core assembly 48, and are electrically connected to the input winding 38a. The output circuit components are mounted within the region 38c of the input winding 38a and the output winding 38b and outside the core assembly 48, and are electrically connected to the output winding 38b. The input circuit components include the power switch 35. The output circuit components include the synchronous rectifier 34, the filter circuit 40, the sensing circuit 42, and the feedback circuit 44.

[0018] Figures 3A - 3B Illustrated is a power converter assembly having a two-piece E-E or E-I core. Figure 3A Perspective view is illustrated. Figure 3BIllustrates a side view.

[0019] Figure 3A Illustrates that the power converter circuit components are mounted on the first surface 46a and are mounted to overlap with one or more portions of the windings of the input winding 38a and the output winding 38b. The power converter circuit components may also be mounted to overlap with one or more portions of the connectors for the electrical connections of the input winding 38a and the output winding 38b.

[0020] Figure 3B Illustrates that the power converter circuit components may also be mounted on the second surface 46b of the circuit layer stack 46. The first surface 46a and the second surface 46b are substantially parallel to each other.

[0021] In one variant, all the power converter circuit components are mounted on the same surface of the stack and outside the magnetic core. This surface may be the first surface 46a or the second surface 46b.

[0022] In one variant, the input circuit components are mounted on one of the first surface 46a and the second surface 46b, and the output circuit components are mounted on the other of the first surface 46a and the second surface 46b.

[0023] In one variant, a first portion of the power converter circuit components is mounted on the first surface 46a, and a second portion of the power converter circuit components is mounted on the second surface 46b.

[0024] The two-piece magnetic core assembly 48 can be an E-I core or an E-E core. For the E-I core, the "I" is placed close to the open end of the "E" to form a three-leg structure. For the E-E core, the corresponding legs of the "E" are placed close to each other. The "E" has a comparable height. Those skilled in the art will understand that any magnetic core assembly can be positioned in the hole of the circuit layer stack 46.

[0025] For the two-piece E-I or E-E shaped core, the magnetic core assembly 48 has a window. The planar energy transfer element 38 is surrounded by the magnetic core assembly 48 and is positioned within the window. The central leg of the E portion extends through the hole of the circuit layer stack 46.

[0026] Figure 4 Is Figure 3A And Figure 3B Is an exploded view of the magnetic core 48 and the circuit layer stack 46 shown in. The magnetic core assembly 48 is a two-piece E-I shaped magnetic core with a central leg. The central leg 48a is substantially perpendicular to the circuit layer stack 46 and extends through the hole of the circuit layer stack 46. When the two pieces of the core are put together, there is an air gap between the end of the central leg 48a and the I portion 48b of the core.

[0027] Figure 5 It is an exploded view showing the electrical connection layer and the winding layer of the simplified circuit layer stack 46. In this embodiment, each circuit layer is a layer in a multi-layer printed circuit board. Those skilled in the art will understand that each circuit layer can be formed as a separate printed circuit board, which is then assembled into a stack.

[0028] In this simplified embodiment, the first surface 46a and the second surface 46b are connection layers. The connection layer can include copper traces used in a power converter to provide electrical connections within the stack 46.

[0029] For the input winding layer 38a and the output winding layer 38b, the windings can be circular or oval spirals, and thus may not necessarily run into the corners of the pcb layer. These corners can include connectors (e.g., pads, vias, and traces) for electrical connections to allow electrical connection to the circuit layer. For each type of winding layer (e.g., input and output), there can be multiple layers of windings.

[0030] The region 38c of the planar energy transfer element is constrained by the circuit features that occupy the most surface area. The region 38c of the planar energy transfer element can include the windings and the connectors for the electrical connections of the larger of the input winding 38a and the output winding 38b. The input winding 38a and the output winding 38b may not occupy the same region because the number of turns (one turn is one loop around the central hole), the spacing between turns, or even the cross-sectional area of the conductor forming the turns can be different. The power circuit components are positioned close to and overlap with either the windings or the associated connectors for electrical connections.

[0031] Each circuit layer can be a printed circuit board or a sub-layer within a printed circuit board. The sub-layer can include isolation and insulation layers to reduce electromagnetic interference (EMI) noise, provide stress relief, or provide electrical isolation between circuit components within a DC-DC converter.

[0032] Numerous specific details have been set forth above to provide a thorough understanding of the present invention. However, it will be apparent to one of ordinary skill in the art that the present invention may be practiced without the use of these specific details. In other instances, well-known materials or methods have not been described in detail to avoid obscuring the present invention. For example, those skilled in the art will understand that the elements in the previously described figures are illustrated for simplicity and clarity and are not necessarily drawn to scale. For example, the dimensions of some of the elements in the figures may be exaggerated relative to other elements to assist in improving understanding of the various embodiments of the present invention. Additionally, common but well-understood elements that are useful or necessary in a commercially viable embodiment are generally not depicted in the figures so as not to unduly obscure the view of these various embodiments of the present invention.

[0033] Reference throughout this specification to "one embodiment", "an embodiment", "one example" or "an example" means that a particular feature, structure, or characteristic described in connection with the embodiment or example is included in at least one embodiment of the present invention. Thus, the appearances of the phrases "in one embodiment", "in an embodiment", "one example" or "an example" in various places throughout this specification are not necessarily all referring to the same embodiment or example. Furthermore, the particular features, structures, or characteristics may be combined in any suitable combination and / or sub-combination in one or more embodiments or examples. The particular features, structures, or characteristics may be included in an integrated circuit, an electronic circuit, a combinational logic circuit, or other suitable components that provide the described functionality.

[0034] The description of the illustrated embodiments of the present invention, including what is described in the abstract, is not intended to be exhaustive or to limit the invention to the exact forms disclosed. While specific embodiments and examples of the present invention have been described herein for illustrative purposes, various equivalent modifications are possible without departing from the broader spirit and scope of the present invention. In fact, it should be understood that any specific example voltage, current, frequency, power range value, time, etc. is provided for explanatory purposes and that other values may also be used in other embodiments and examples in accordance with the teachings of the present invention.

[0035] Although the present invention is defined in the claims, the present invention may alternatively be defined according to the following examples:

[0036] Embodiment 1. A power converter includes: a circuit layer stack having a first surface and holes extending through each circuit layer, a portion of the circuit layers forming energy transfer elements, the energy transfer elements including an input winding having at least one winding layer and an output winding having at least one winding layer, each winding layer including a winding and a connection member for electrical connection; a magnetic core positioned substantially perpendicular to the stack within the holes; a region of the circuit layer stack that is coplanar with the first surface and includes the windings and connection members for electrical connection of the input winding and the output winding; and power converter circuit components mounted on the first surface of the stack, the power converter circuit components including: an input circuit component mounted within the region of the stack and outside the magnetic core, wherein the input circuit component is electrically connected to the input winding; and an output circuit component mounted within the region of the stack and outside the magnetic core, wherein the output circuit component is electrically connected to the output winding.

[0037] Embodiment 2. The power converter according to Embodiment 1, wherein the power converter circuit components are further mounted on a second surface of the circuit layer stack, and the first surface and the second surface are substantially parallel to each other.

[0038] Embodiment 3. The power converter according to Embodiment 2, wherein: a first portion of the power converter circuit components is an input converter component mounted on the first surface, and a second portion of the power converter circuit components is an output converter component mounted on the second surface.

[0039] Embodiment 4. The power converter according to Embodiment 1, wherein a portion of the power converter circuit components is mounted over a portion of the windings of the input winding and the output winding.

[0040] Embodiment 5. The power converter according to Embodiment 4, wherein the portion of the power converter circuit components is further mounted over a portion of the connection members for electrical connection of the input winding and the output winding.

[0041] Embodiment 6. The power converter according to Embodiment 1, wherein a portion of the power converter circuit components is mounted over a portion of the connection members for electrical connection of the input winding and the output winding.

[0042] Embodiment 7. The power converter according to Embodiments 1 to 6 further includes a housing surrounding the stack, the magnetic core, and the power converter circuit components.

[0043] Example 8. The power converter according to any one of Examples 1 to 7, wherein the magnetic core is an E-E shaped core.

[0044] Example 9. The power converter according to any one of Examples 1 to 7, wherein the magnetic core is an E-I shaped core.

[0045] Example 10. The power converter according to any one of Examples 1 to 9, wherein the power converter circuit components include a power switch, a synchronous rectifier, a controller, a filter circuit, a sensing circuit, and a feedback circuit.

[0046] Example 11. The power converter according to any one of Examples 1 to 10, wherein each circuit layer of the circuit layer stack is a printed circuit board.

[0047] Example 12. The power converter according to any one of Examples 1 to 10, wherein the circuit layer stack is a multi-layer printed circuit board.

[0048] Example 13. A power converter, comprising: a magnetic core having a window; a circuit layer stack positioned within the window, a portion of the circuit layer forming an energy transfer element, the energy transfer element including an input winding having at least one winding layer and an output winding having at least one winding layer, each winding layer including a planar winding and a connection member for electrical connection; a region of the stack including the planar winding and connection members for electrical connection of the input winding and the output winding; power converter circuit components mounted on a first surface of the stack and electrically connected to one of the input winding and the output winding, wherein the power converter circuit components are mounted within the region of the stack and outside the magnetic core.

[0049] Example 14. The power converter according to Example 13, wherein the power converter circuit components are further mounted on a second surface of the stack, and the first surface and the second surface are substantially parallel to each other.

[0050] Example 15. The power converter according to Example 14, wherein a portion of the power converter circuit components is mounted over a portion of the windings of the input winding and the output winding.

[0051] Example 16. The power converter according to Example 15, wherein the portion of the power converter circuit components is mounted over a portion of the connection members for electrical connection of the input winding and the output winding.

[0052] Example 17. The power converter according to any one of Examples 13 to 16, further comprising a housing surrounding the stack, the magnetic core, and the power converter circuit components.

[0053] Example 18. The power converter according to Examples 13 to 17, wherein the power converter circuit components are selected from the group consisting of a power switch, a synchronous rectifier, a controller, a filter circuit, a sensing circuit, and a feedback circuit.

Claims

1. A power converter, comprising: a stack of circuit layers having a first surface and holes extending through each circuit layer, a portion of the circuit layers forming an energy transfer element, the energy transfer element including an input winding having at least one winding layer and an output winding having at least one winding layer, each winding layer including a winding and a connector for electrical connection; a magnetic core positioned within the aperture substantially perpendicular to the stack; a region of the circuit layer stack, the region being coplanar with the first surface and comprising the winding and connectors for electrical connection of the input winding and the output winding; as well as a power converter circuit component mounted on a first surface of the stack, the power converter circuit component comprising: an input circuit component mounted within the region of the stack and outside the magnetic core, wherein the input circuit component is electrically connected to the input winding; as well as An output circuit component is mounted within the region of the stack and outside the magnetic core, wherein the output circuit component is electrically connected to the output winding. 2 . The power converter of claim 1 , wherein the power converter circuit components are also mounted on a second surface of the circuit layer stack, and the first surface and the second surface are substantially parallel to each other.

3. The power converter according to claim 2, wherein: a first portion of the power converter circuit components is an input converter component mounted on the first surface, and The second portion of the power converter circuit components is an output converter component mounted on the second surface. 4 . The power converter of claim 1 , wherein a portion of the power converter circuit components are mounted over a portion of the windings of the input winding and the output winding. 5 . The power converter of claim 4 , wherein the portion of the power converter circuit component is also mounted on a portion of the connector for electrical connection of the input winding and the output winding. 6 . The power converter according to claim 1 , wherein a portion of the power converter circuit component is mounted on a portion of the connection member for electrical connection of the input winding and the output winding. 7 . The power converter of claim 1 , further comprising a housing surrounding the stack, the magnetic core, and the power converter circuit components.

8. The power converter of claim 1, wherein the magnetic core is an EE-shaped core.

9. The power converter of claim 1, wherein the magnetic core is an EI-shaped core. 10 . The power converter of claim 1 , the power converter circuit components comprising a power switch, a synchronous rectifier, a controller, a filter circuit, a sensing circuit, and a feedback circuit.

11. The power converter of claim 1 , the circuit layer stack further comprising each circuit layer being a printed circuit board.

12. The power converter of claim 1 wherein the circuit layer stack is a multi-layer printed circuit board.

13. A power converter comprising: a magnetic core having a window; a stack of circuit layers positioned within the window, a portion of the circuit layers forming an energy transfer element, the energy transfer element comprising an input winding having at least one winding layer and an output winding having at least one winding layer, each winding layer comprising a planar winding and a connector for electrical connection; a region of the stack, the region comprising the planar winding and connectors for electrical connection of the input winding and the output winding; A power converter circuit component is mounted on a first surface of the stack and is electrically connected to one of the input winding and the output winding, wherein the power converter circuit component is mounted within the region of the stack and outside the magnetic core. 14 . The power converter of claim 13 , wherein the power converter circuit components are also mounted on a second surface of the stack, and the first surface and the second surface are substantially parallel to each other.

15. The power converter of claim 14, wherein a portion of the power converter circuit components are mounted over a portion of the windings of the input winding and the output winding. 16 . The power converter of claim 15 , wherein the portion of the power converter circuit component is mounted on a portion of the connector for electrical connection of the input winding and the output winding.

17. The power converter of claim 13 further comprising a housing surrounding the stack, the magnetic core, and the power converter circuit components.

18. The power converter of claim 13, wherein the power converter circuit components are selected from the group consisting of a power switch, a synchronous rectifier, a controller, a filter circuit, a sensing circuit, and a feedback circuit.

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