Power converter and inductor assembly thereof
By using a partially overlapping area between windings in the power converter to adjust the coupling coefficient, the problem of low efficiency of coupled inductors in compact packages is solved, resulting in a more efficient and compact power converter.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- CHENGDU MONOLITHIC POWER SYST
- Filing Date
- 2025-10-16
- Publication Date
- 2026-05-08
AI Technical Summary
In existing power converters, it is difficult to maintain high efficiency in a compact package for the design of coupled inductors, and the winding spacing adjustment is limited, which affects system performance.
The coupling coefficient is determined by the partial overlap area between windings. Instead of relying on the physical distance between windings, the coupling coefficient is adjusted by designing the partial overlap area between windings, thus achieving a more compact design.
This enables a more compact and efficient power converter design, reducing package size while maintaining the required coupling coefficient and improving system performance.
Smart Images
Figure CN122000177A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to an electronic circuit, and more specifically, to a power converter. Background Technology
[0002] Inductors are widely used in various circuits, such as filters and power converters. In a power converter, a single output inductor can be used to couple a switching node to the output node of the power converter. Coupled inductors can be used to couple the output phases of a multiphase power converter together. As is known in the art, a power converter converts input power into output power, thereby providing the required voltage and current to the load. A multiphase power converter consists of multiple power stages connected in parallel and operating in staggered phases. Multiphase power converters offer several advantages, including reduced output ripple voltage, improved transient performance, and reduced input capacitor requirements for ripple current ratings.
[0003] Currently, coupled inductors are widely used in power converters. In their design, symmetrical windings are often used, and the current directions of adjacent windings are opposite to achieve anti-coupling between the windings. Summary of the Invention
[0004] Therefore, in order to solve the above-mentioned technical problems, the present invention proposes an inductor assembly that integrates a coupling inductor, and a compact and efficient power converter including the inductor assembly.
[0005] According to an embodiment of the present invention, a power converter is provided, comprising an inductor assembly and two power chips. The inductor assembly includes two windings sharing a common magnetic core to form a coupled inductor. Each winding includes a body, a first portion, and a second portion. The body of each winding extends toward the top surface of the inductor assembly, the first portion of each winding extends to the bottom surface of the inductor assembly to form a first end of the winding, and the second portion of each winding extends to the bottom surface of the inductor assembly to form a second end of the winding. Each power chip includes a pair of switches, the switching node formed by the pair of switches being electrically connected to the first end of the corresponding winding, the second end of the corresponding winding being configured to provide an output voltage. A partially overlapping region exists between the two windings, the partially overlapping region being used to determine the coupling coefficient between the coupled inductors.
[0006] According to an embodiment of the present invention, a power converter is provided, comprising an inductor assembly and two power chips. The inductor assembly includes four windings sharing a common magnetic core to form a coupled inductor. Each winding includes a body, a first portion, and a second portion. The body of each winding extends toward the top surface of the inductor assembly, the first portion of each winding extends to the bottom surface of the inductor assembly to form a first end of the winding, and the second portion of each winding extends to the bottom surface of the inductor assembly to form a second end of the winding. Two power chips are positioned on opposite sides of the inductor assembly, each power chip including two pairs of switches, each pair of switches forming a switch node electrically connected to the first end of the corresponding winding. The second end of the corresponding winding is configured to provide an output voltage.
[0007] According to an embodiment of the present invention, an inductor assembly for a power converter is provided, comprising a magnetic core, a first winding and a second winding sharing the magnetic core. Each of the first winding and the second winding includes a body, a first portion, and a second portion. The body of each winding extends toward the top surface of the inductor assembly, the first portion of each winding extends to the bottom surface of the inductor assembly to form a first end of the winding, and the second portion of each winding extends to the bottom surface of the inductor assembly to form a second end of the winding. A first partial overlap region is provided between the first winding and the second winding, the first partial overlap region being used to determine the coupling coefficient between the first winding and the second winding.
[0008] Compared to traditional technologies, the inductor assembly of this invention determines the coupling coefficient between windings by partially overlapping the windings, thereby reducing the spacing between the windings and enabling a more compact and efficient power converter design. Attached Figure Description
[0009] To better understand this invention, it will be described in detail with reference to the following drawings. Identical or similar elements are referred to by the same reference numerals.
[0010] Figure 1 A schematic diagram of a power converter 100 according to an embodiment of the present invention is shown.
[0011] Figure 2 A perspective view of the inductor assembly 20 is shown.
[0012] Figure 3A Examples of embodiments of the present invention are shown. Figure 1 A perspective view of the inductor assembly 30 shown.
[0013] Figure 3B A perspective view of a winding 302 according to an embodiment of the present invention is shown.
[0014] Figure 3CA perspective view of a winding 303 according to an embodiment of the present invention is shown.
[0015] Figure 4 Examples of embodiments of the present invention are shown. Figure 3A The front perspective view of the inductor assembly 30 shown.
[0016] Figure 5 Examples of embodiments of the present invention are shown. Figure 3A The top perspective view of the inductor assembly 30 shown.
[0017] Figure 6 Examples of embodiments of the present invention are shown. Figure 3A The inductor assembly 30 shown is a side perspective view.
[0018] Figure 7 Examples of embodiments of the present invention are shown. Figure 3A Bottom view of the inductor assembly 30 shown.
[0019] Figure 8 Examples of embodiments of the present invention are shown. Figure 1 The layout 80 of the power converter 100 shown.
[0020] Figure 9 A schematic diagram of a power converter 200 according to an embodiment of the present invention is shown.
[0021] Figure 10 A perspective view of an inductor assembly 90 according to an embodiment of the present invention is shown.
[0022] Figure 11 Examples of embodiments of the present invention are shown. Figure 9 The front perspective view of the inductor assembly 90 shown.
[0023] Figure 12 Examples of embodiments of the present invention are shown. Figure 9 The top perspective view of the inductor assembly 90 shown.
[0024] Figure 13 Examples of embodiments of the present invention are shown. Figure 9 The inductor assembly 90 shown is a side perspective view.
[0025] Figure 14 Examples of embodiments of the present invention are shown. Figure 9 A top view of the inductor assembly 90 shown.
[0026] Figure 15 The inductance curves of output inductors 220-1 and 220-2 according to embodiments of the present invention are shown.
[0027] Figure 16Examples of embodiments of the present invention are shown. Figure 9 The layout 160 of the power converter 200 shown is illustrated. Detailed Implementation
[0028] Specific embodiments of the present invention will now be described in detail. It should be noted that the embodiments described herein are for illustrative purposes only and are not intended to limit the invention. In the following description, numerous specific details are set forth in order to provide a thorough understanding of the invention. However, it will be apparent to those skilled in the art that these specific details are not necessary to practice the invention. In other instances, well-known circuits, materials, or methods have not been specifically described to avoid obscuring the invention.
[0029] Throughout this specification, references to “an embodiment,” “an example,” or “an example” mean that a particular feature, structure, or characteristic described in connection with that embodiment or example is included in at least one embodiment of the invention. Therefore, the phrases “in an embodiment,” “in an embodiment,” “an example,” or “an example” appearing in various places throughout the specification do not necessarily refer to the same embodiment or example. Furthermore, specific features, structures, or characteristics can be combined in one or more embodiments or examples in any suitable combination and / or sub-combination. Moreover, those skilled in the art will understand that the accompanying drawings provided herein are for illustrative purposes and are not necessarily drawn to scale. It should be understood that when an element is referred to as “coupled” or “connected” to another element, it can be directly coupled to the other element or there may be intermediate elements. Conversely, when an element is referred to as “directly coupled to” or “directly connected” to another element, there are no intermediate elements. The same reference numerals indicate the same elements. The term “and / or” as used herein includes any and all combinations of one or more of the associated listed items.
[0030] Figure 1 A schematic diagram of a power converter 100 according to an embodiment of the present invention is shown. Figure 1 In the illustrated embodiment, the power converter 100 includes two-phase switching circuits 130 (i.e., 130-1, 130-2), wherein each phase switching circuit includes an output inductor 120 (i.e., 120-1, 120-2) and power chips 110 (i.e., 110-1, 110-2). Figure 1In the example, each power chip 110 includes a driver 115, a high-side switch M1 (e.g., a Metal-Oxide Semiconductor Transistor, i.e., a MOSFET), and a low-side switch M2 (e.g., a MOSFET). The driver 115 drives the high-side switch M1 and the low-side switch M2. Each power chip 110 includes an input node 111 configured to receive an input voltage VIN, a control node 112 configured to receive switch control signals PWM (i.e., PWM1, PWM2), a switch node 113 formed by switches M1 and M2, and a reference node 114 electrically connected to a reference ground. Each phase switching circuit 130 receives the input voltage VIN and generates an output voltage VOUT (i.e., VOUT1, VOUT2) via the corresponding power chip 110 and output inductor 120. The output voltages VOUT1 and VOUT2 of switching circuits 130-1 and 130-2 can be connected together and operate out of phase to generate a multiphase output voltage. For example, output voltage nodes 131 and 132 can be connected together, with each switching circuit 130 providing one phase of a multi-phase output voltage. In this embodiment, the power converter 100 can have more switching circuits to include more phases. Figure 1 In the example, each switching circuit 130 is a buck circuit. Those skilled in the art will understand that, depending on the application, each switching circuit 130 may also be configured as a boost circuit or other types of switching circuits.
[0031] Furthermore, the inductor assembly 30 includes two windings to form output inductors 120-1 and 120-2, respectively. In one embodiment, the first winding forms output inductor 120-1, and the second winding forms output inductor 120-2. The first winding has a first end 123 and a second end 124, wherein the first end 123 is electrically connected to a switching node 113 formed by switches M1 and M2 of power chip 110-1, and the second end 124 is electrically connected to an output node 131 to provide an output voltage VOUT1. The second winding has a first end 125 and a second end 126, wherein the first end 125 is electrically connected to the switching node 113 formed by switches M1 and M2 of power chip 110-2, and the second end 126 is electrically connected to an output node 132 to provide an output voltage VOUT2.
[0032] In one embodiment, output inductors 120-1 and 120-2 are designed as anti-coupled inductors, whose coupling coefficient is determined by the partial overlap region between the windings, rather than by the physical distance between the windings. For example, this coupling coefficient can be adjusted by changing the size of the partial overlap region between the windings (e.g., the length of the overlap).
[0033] Controller 140 generates switching control signals PWM1 and PWM2 to drive power chips 110-1 and 110-2 respectively, so as to keep the output voltages VOUT1 and VOUT2 stable. For clarity, Figure 1 Other circuits or components, such as input capacitors, output capacitors, detection circuits, etc., are not shown.
[0034] Figure 2 A perspective view of inductor assembly 20 is shown. Inductor assembly 20 includes symmetrical windings 202 and 203 magnetically coupled together via a magnetic core 201. Windings 202 and 203 can be used to form... Figure 1 The output inductors 120-1 and 120-2 are shown, and are essential components of the power converter 100. To achieve the anti-coupling coefficient between the output inductors 120-1 and 120-2, windings 202 and 203 have opposite current directions. Figure 2 As shown, windings 202 and 203 are placed in parallel. The spacing DW between windings 202 and 203 is determined according to the requirements of their coupling relationship. By changing the spacing DW, the coupling coefficient between windings 202 and 203 can be fine-tuned to meet specific design requirements. However, when there are packaging constraints, it is difficult to maintain a large spacing DW between windings 202 and 203, which may limit the overall performance of the system.
[0035] Figure 3A Examples of embodiments of the present invention are shown. Figure 1 The diagram shows a perspective view of the inductor assembly 30. The inductor assembly 30 includes windings 302 and 303 magnetically coupled together via a magnetic core 301. Winding 302 forms... Figure 1 The output inductor 120-1 shown has a winding 303 forming... Figure 1 The output inductor 120-2 shown is an essential component of the power converter 100, wherein output inductors 120-1 and 120-2 are necessary components of the power converter 100.
[0036] Windings 302 and 303 have a partially overlapping region in a direction parallel to the top surface 311 and bottom surface 312 of the inductor assembly 30, and this partially overlapping region determines the coupling coefficient between the coupled inductors formed by windings 302 and 303. Specifically, the bodies 302-1 of winding 302 and 303-1 of winding 303 are parallel to each other and both perpendicular to the top surface 311 and bottom surface 312 of the inductor assembly 30. The bodies 302-1 of winding 302 and 303-1 of winding 303 partially overlap each other to form anti-coupling between windings 302 and 303. For clarity, the terms "top" and "bottom" refer to directions relative to the substrate supporting the inductor assembly 30; for example, the bottom surface of the inductor assembly 30 is the surface close to the substrate, and the top surface of the inductor assembly 30 is the surface away from the substrate. This substrate may include, for example, a printed circuit board (PCB) or other type of substrate. In one embodiment, the body 302-1 of winding 302 and the body 303-1 of winding 303 have an "n" shape and both extend toward the top surface 311 of inductor assembly 30.
[0037] The winding 302 also includes portions 302-2 and 302-3, wherein the main body 302-1 of the winding 302 connects portions 302-2 and 302-3 of the winding 302, and portions 302-2 and 302-3 of the winding 302 are at least partially exposed on the bottom surface 312 of the inductor assembly 30. Portion 302-2 of the winding 302 extends on the bottom surface 312 of the inductor assembly 30 to form a first end 123 of the winding 302, the first end 123 of the winding 302 being electrically connected to... Figure 1 The switching node 113 of the power chip 110-1 is shown. A portion 302-3 of the winding 302 extends on the bottom surface 312 of the inductor assembly 30 to form a second end 124 of the winding 302, which is electrically connected to... Figure 1 The output node 131 shown provides the output voltage VOUT1. In one embodiment, a portion 302-2 of the winding 302 extends toward a side 30-3 of the core 301, and a portion 302-3 of the winding 302 extends toward a side 30-4 of the core 301, wherein the side 30-3 is perpendicular to the y-axis and opposite to the side 30-4.
[0038] Similarly, winding 303 also includes portions 303-2 and 303-3, wherein the body 303-1 of winding 303 connects portions 303-2 and 303-3 of winding 303, and portions 303-2 and 303-3 of winding 303 are at least partially exposed on the bottom surface 312 of inductor assembly 30. Portion 303-2 of winding 303 extends on the bottom surface 312 of inductor assembly 30 to form a first end 125 of winding 303, the first end 125 of winding 303 being electrically connected to... Figure 1 The switching node 113 of the power chip 110-1 is shown. A portion 303-3 of the winding 303 extends on the bottom surface 312 of the inductor assembly 30 to form a second end 126 of the winding 303, which is electrically connected to... Figure 1 The output node 132 shown provides the output voltage VOUT2. In one embodiment, a portion 303-2 of the winding 303 extends toward the side 30-4 of the core 301, and a portion 303-3 of the winding 303 extends toward the side 30-3 of the core 301.
[0039] like Figure 3A As shown, portion 302-2 of winding 302 is close to edge 30-1 of the bottom surface 312 of inductor assembly 30, while portion 302-3 of winding 302 is located further away from edge 30-1 (e.g., in the middle region of bottom surface 312). Portion 303-2 of winding 303 is close to edge 30-2 of the bottom surface 312 of inductor assembly 30, while portion 303-3 of winding 303 is located further away from edge 30-2 (e.g., in the middle region of bottom surface 312), with edges 30-1 and 30-2 opposite each other.
[0040] In one embodiment, winding 302 is partially exposed on side 30-6 of magnetic core 301, and winding 303 is partially exposed on side 30-5 of magnetic core 301, wherein sides 30-5 and 30-6 are both perpendicular to the x-axis and opposite to each other. In one embodiment, windings 302 and 303 may have the same length, width, and height. The lengths of windings 302 and 303 are less than the length of magnetic core 301, wherein the lengths of windings 302, windings 303, and magnetic core 301 are, for example, along... Figure 3A The x-axis direction is shown in the figure. The heights of windings 302 and 303 are less than or equal to the height of core 301, wherein the heights of windings 302, 303, and core 301 are, for example, along the x-axis. Figure 3A The direction of the z-axis shown is obtained by measurement.
[0041] Unlike conventional methods that rely on adjusting the symmetrical winding spacing DW to control the coupling coefficient, this disclosure employs mutually staggered windings 302 and 303, partially overlapping them, to control the coupling coefficient between the windings. The partial overlap between windings 302 and 303 determines their coupling coefficient. This method allows the gap between windings 302 and 303 to be designed to be as small as possible, thereby reducing the size of the inductor assembly 30 and enabling a more compact and efficient power converter design. Therefore, this disclosure achieves a smaller package while still providing the required coupling coefficient, making it an attractive solution for a wide range of applications.
[0042] Figure 3BA perspective view of a winding 302 according to an embodiment of the present invention is shown. Figure 3C A perspective view of a winding 303 according to an embodiment of the present invention is shown. Figure 3B and Figure 3C In the example, both winding 302 and winding 303 are one turn. Winding 302 and winding 303 can be flat copper wire with an enamel coating.
[0043] Figure 4 Examples of embodiments of the present invention are shown. Figure 3A The diagram shows a front perspective view of the inductor assembly 30. To illustrate the direction of current flow, dashed line 41 shows the current flowing through winding 302, for example from a first end 123 to a second end 124 of winding 302. Dashed line 42 shows the current flowing through winding 303, for example from a first end 125 to a second end 126 of winding 303. In the partially overlapping region of windings 302 and 303, the bodies 302-1 of winding 302 and the bodies 303-1 of winding 303 partially overlap each other to have currents in opposite directions, thus the magnetic flux generated by windings 302 and 303 at least partially cancels each other out. The length DOL of the partially overlapping region of windings 302 and 303 determines their coupling coefficient, thereby achieving optimal performance. Specifically, the longer the length DOL, the greater the coupling coefficient between winding 302 and winding 303; conversely, the shorter the length DOL, the smaller the coupling coefficient between winding 302 and winding 303.
[0044] Figure 5 Examples of embodiments of the present invention are shown. Figure 3A The top perspective view of the inductor assembly 30 shown. Figure 6 Examples of embodiments of the present invention are shown. Figure 3A The inductor assembly 30 shown is a side perspective view. Figure 5 As shown, due to the partial overlap between windings 302 and 303, the gap GP between the body 302-1 of winding 302 and the body 303-1 of winding 303 (e.g., the distance between the body 302-1 of winding 302 and the body 303-1 of winding 303) can be designed to be as small as possible, thereby reducing the size of the inductor assembly 30 while still maintaining the desired coupling coefficient. This achieves a more compact design and higher overall system efficiency. In one example, the gap GP is a small distance, for example, less than 0.4 mm.
[0045] Figure 7 Examples of embodiments of the present invention are shown. Figure 3A The bottom view of the inductor assembly 30 is shown. Figure 7In the illustrated embodiment, the first end 123 and the second end 124 of winding 302, and the first end 125 and the second end 126 of winding 303 are located on the bottom surface 312 of inductor assembly 30, playing a crucial role in current flow and power transmission. The first end 123 of winding 302 forms or is electrically connected to a switch pad PSW1, which is electrically connected to the switching node 113 of power chip 110-1. The second end 124 of winding 302 forms or is electrically connected to an output pad PVO1, which is electrically connected to an output voltage node 131 to provide an output voltage VOUT1. The first end 125 of winding 303 forms or is electrically connected to a switch pad PSW2, which is electrically connected to the switching node 113 of power chip 110-2. The second end 126 of winding 303 forms an output pad PVO2 or is electrically connected to the output pad PVO2, which is electrically connected to the output voltage node 132 to provide the output voltage VOUT2.
[0046] like Figure 7 As shown, output pads PVO1 and PVO2 are located in the middle region of the bottom surface 312 of the inductor assembly 30, and not near the edge of the bottom surface 312, thereby providing more space for each pad to improve layout and soldering flexibility. In one embodiment, output pads PVO1 and PVO2 can be electrically connected together via external interconnects or internal interconnects within the inductor assembly 30, thereby making the power converter 100 a two-phase power converter. In another embodiment, there may be no electrical connection between output pads PVO1 and PVO2, allowing the power converter 100 to operate as two independent converters.
[0047] Figure 8 Examples of embodiments of the present invention are shown. Figure 1 The layout 80 of the power converter 100 shown. Figure 8 An example connection between the inductor assembly 30 and the power chips 110-1 and 110-2 is shown. In this compact and efficient layout, the inductor assembly 30 is positioned between the two power chips 110-1 and 110-2, i.e., the power chips 110-1 and 110-2 are placed on opposite sides of the inductor assembly 30, thereby achieving a smaller number of components, optimizing thermal management, and enhancing the overall system performance.
[0048] exist Figure 8In the example, interconnect 801 electrically connects power chip 110-1 to the first terminal 123 of winding 302 in inductor assembly 30, allowing current to flow from power chip 110-1 to switching pad PSW1. Interconnect 802 electrically connects power chip 110-2 to the first terminal 125 of winding 303 in inductor assembly 30, allowing current to flow from power chip 110-2 to switching pad PSW2. Interconnect 803 electrically connects the second terminal 124 of winding 302 and the second terminal 126 of winding 303 to provide an output voltage to the load, allowing current to flow from inductor assembly 30 to the load. Interconnects 801–803 can be metallic structures, such as copper traces on a PCB. The configuration of inductor assembly 30 allows output pads PVO1 and PVO2 to be placed in the intermediate region, improving the layout for a more efficient, reliable, and compact power converter.
[0049] In one example, multiple electronic components 81 may be mounted near power chip 110-1, and multiple electronic components 82 may be mounted near power chip 110-2. Electronic components 81 and 82 may include resistors, capacitors, diodes, etc., for filtering, regulating, and controlling the output voltage and current to ensure reliable and efficient operation of the power converter 100.
[0050] The concepts disclosed herein can be extended to more phases, such as Figure 9 The four-phase configuration shown achieves higher power density and higher efficiency. By employing the winding configuration of embodiments of this disclosure, both anti-coupling and high power density can be achieved, thereby enabling the manufacture of a high-efficiency, compact multiphase power converter.
[0051] Figure 9 A schematic diagram of a power converter 200 according to an embodiment of the present invention is shown. Figure 9 In the illustrated embodiment, the power converter 200 includes a four-phase switching circuit 230 (i.e., 230-1, 230-2, 230-3, 230-4), wherein each phase switching circuit includes an output inductor 220 (i.e., 220-1, 220-2, 220-3, 220-4), a pair of switches, and a corresponding driver for driving the pair of switches.
[0052] exist Figure 9In the example, each power chip 210 (i.e., 210-1, 210-2) provides two pairs of switches for a two-phase switching circuit (i.e., a first pair of switches including high-side switch M1 and low-side switch M2, and a second pair of switches including high-side switch M3 and low-side switch M4) and two drivers 217, 218, thereby enabling a more compact and efficient power converter design. Switching circuit 230-1 includes output inductor 220-1, switches M1 and M2 in power chip 210-1, and driver 217 in power chip 210-1. Switching circuit 230-2 includes output inductor 220-2, switches M1 and M2 in power chip 220-2, and driver 217 in power chip 210-2. Switching circuit 230-3 includes output inductor 220-3, switches M3 and M4 in power chip 210-1, and driver 218 in power chip 210-1. The switching circuit 230-4 includes an output inductor 220-4, switches M3 and M4 in the power chip 210-2, and a driver 218 in the power chip 210-2.
[0053] Each power chip 210 has an input node 211 configured to receive an input voltage VIN, a control node 212 configured to receive a first switching control signal (i.e., PWM1, PWM2), a control node 213 configured to receive a second switching control signal (i.e., PWM3, PWM4), a first switching node 214 configured to provide an output voltage VOUT (i.e., VOUT1, VOUT2) via corresponding output inductors 220 (i.e., 220-1, 220-2), a second switching node 215 configured to provide an output voltage VOUT (i.e., VOUT3, VOUT4) via corresponding output inductors 220 (i.e., 220-3, 220-4), and a reference node 216 electrically connected to a reference ground. The output voltages VOUT1 to VOUT4 can be connected together and operate out of phase to generate a multiphase output voltage, which can bring multiple advantages, including improved efficiency, reduced ripple, and increased power density. For example, output voltage nodes 231–234 can be connected together, where each switching circuit 230 provides one phase of a multi-phase output voltage. Figure 9 In the examples, the switching circuits 230 are all buck circuits. Those skilled in the art will understand that, depending on the application, each switching circuit 230 can also be configured as a boost circuit or other types of switching circuits.
[0054] Output inductors 220-1, 220-2, 220-3, and 220-4 consist of four windings integrated into an inductor assembly 90 sharing a single magnetic core, enabling a more compact package and reducing the total number of components. This design offers several advantages, including reduced size, increased efficiency, and improved reliability. The magnetic core can be a monolithic or modular structure, made from the same magnetic materials commonly used in magnetic cores. Output inductors 220-1 and 220-2 are anti-coupled to each other as a first set of coupled inductors, and output inductors 220-3 and 220-4 are anti-coupled to each other as a second set of coupled inductors.
[0055] exist Figure 9 In the example, the winding forming output inductor 220-1 has a first end 221 and a second end 222, with the first end 221 electrically connected to the switching node 214 of power chip 210-1 and the second end 222 electrically connected to the output voltage node 231 to provide output voltage VOUT1. The winding forming output inductor 220-2 has a first end 223 and a second end 224, with the first end 223 electrically connected to the switching node 214 of power chip 210-2 and the second end 224 electrically connected to the output voltage node 232 to provide output voltage VOUT2. The winding forming output inductor 220-3 has a first end 225 and a second end 226, with the first end 225 electrically connected to the switching node 215 of power chip 210-1 and the second end 226 electrically connected to the output voltage node 233 to provide output voltage VOUT3. The winding forming the output inductor 220-4 has a first end 227 and a second end 228, the first end 227 being electrically connected to the switching node 215 of the power chip 210-2, and the second end 228 being electrically connected to the output voltage node 234 to provide the output voltage VOUT4.
[0056] The controller 240 generates switching control signals PWM1 to PWM4 to drive power chips 210-1 and 210-2 respectively, so as to keep the output voltages VOUT1 to VOUT4 stable. For clarity, Figure 9 Other circuits or components, such as input capacitors, output capacitors, detection circuits, etc., are not shown.
[0057] Figure 10 A perspective view of an inductor assembly 90 according to an embodiment of the present invention is shown. The inductor assembly 90 includes four windings 902 to 905 magnetically coupled together by a magnetic core 901. Winding 902 forms an output inductor 220-1, winding 903 forms an output inductor 220-2, winding 904 forms an output inductor 220-3, and winding 905 forms an output inductor 220-4.
[0058] The bodies of each of windings 902 to 905 (i.e., 902-1, 903-1, 904-1, 905-1) are parallel to each other, and the bodies of windings 902 to 905 are perpendicular to the top surface 921 and bottom surface 922 of the inductor assembly 90. Windings 902 and 903 partially overlap each other; for example, the bodies 902-1 of winding 902 and 903-1 of winding 903 partially overlap each other to form anti-coupling between windings 902 and 903. Windings 904 and 905 partially overlap each other; for example, the bodies 904-1 and 905-1 of windings 904 and 905 partially overlap each other to form anti-coupling between windings 904 and 905. In one embodiment, the bodies 902-1, 903-1, 904-1, and 905-1 of windings 902 to 905 are all n-shaped and extend toward the top surface 921 of inductor assembly 90.
[0059] Winding 902 also includes portions 902-2 and 902-3 ( Figure 10 (Not shown), portions 902-2 and 902-3 of winding 902 are at least partially exposed on the bottom surface 922 of inductor assembly 90. The body 902-1 of winding 902 connects portions 902-2 and 902-3 of winding 902. Portion 902-2 of winding 902 extends on the bottom surface 922 of inductor assembly 90 to form a first end 221 of winding 902. Portion 902-3 of winding 902 extends on the bottom surface 922 of inductor assembly 90 to form a second end 222 of winding 902. Winding 903 also includes portions 903-2 and 903-3, which are at least partially exposed on the bottom surface 922 of inductor assembly 90. The body 903-1 of winding 903 connects portions 903-2 and 903-3 of winding 903. A portion 903-2 of winding 903 extends on the bottom surface 922 of inductor assembly 90 to form a first end 223 of winding 903. A portion 903-3 of winding 903 extends on the bottom surface 922 of inductor assembly 90 to form a second end 224 of winding 903. Winding 904 also includes portions 904-2 and 904-3 ( Figure 10 (Not shown), portions 904-2 and 904-3 of winding 904 are at least partially exposed on the bottom surface 922 of inductor assembly 90. The body 904-1 of winding 904 connects portions 904-2 and 904-3 of winding 904. Portion 904-2 of winding 904 extends on the bottom surface 922 of inductor assembly 90 to form a first end 225 of winding 904. Portion 904-3 of winding 904 extends on the bottom surface 922 of inductor assembly 90 to form a second end 226 of winding 904. Winding 905 also includes portions 905-2 and 905-3 (… Figure 10(Not shown), portions 905-2 and 905-3 of winding 905 are at least partially exposed on the bottom surface 922 of inductor assembly 90. The body 905-1 of winding 905 connects portions 905-2 and 905-3 of winding 905. Portion 905-2 of winding 905 extends on the bottom surface 922 of inductor assembly 90 to form a first end 227 of winding 905. Portion 905-3 of winding 905 extends on the bottom surface 922 of inductor assembly 90 to form a second end 228 of winding 905.
[0060] The partial overlap between windings 902 and 903 is used to control the coupling coefficient between output inductors 220-1 and 220-2. The partial overlap between windings 904 and 905 is used to control the coupling coefficient between output inductors 220-3 and 220-4. Figure 10 In the example, along the y-axis, the four windings are placed in the following order from front to back: winding 903, winding 902, winding 905, and winding 904. Different winding placement orders may be used in different applications. Figure 10 The specific sequence shown maximizes the partial overlap between windings 903 and 902 and between windings 905 and 904, while maintaining a large spacing between the first set of windings formed by windings 902 and 903 and the second set of windings formed by windings 904 and 905.
[0061] In one embodiment, portions 902-2 of winding 902 and 904-2 of winding 904 are located near one edge of the bottom surface 922 of inductor assembly 90, and portions 903-2 of winding 903 and 905-2 of winding 905 are located near another edge of the bottom surface 922, the two edges being opposite each other. In contrast, portions 902-3 of winding 902, 903-3 of winding 903, 904-3 of winding 904, and 905-3 of winding 905 are located further away from the edge of the bottom surface 922, for example, in the middle region of the bottom surface 922. In one embodiment, portions 902-2 of winding 902, 904-2 of winding 904, 903-3 of winding 903, and 905-3 of winding 905 extend toward the side 90-4 of magnetic core 901. The portions 902-3 of winding 902, 904-3 of winding 904, 903-2 of winding 903, and 905-2 of winding 905 extend toward the side 90-3 of magnetic core 901, with side 90-3 and side 90-4 facing each other.
[0062] In one embodiment, windings 902 and 904 are partially exposed on side 90-5 of the core 901, and windings 903 and 905 are partially exposed on side 90-6 of the core 901, with side 90-5 and side 90-6 opposite to each other. In one embodiment, windings 902-905 may have the same length, width, and height. The length of windings 902-905 is less than the length of the core 901, wherein the length of windings 902-905 and the length of the core 901 are, for example, along... Figure 10 The x-axis direction is shown in the figure. The height of windings 902-905 is less than or equal to the height of core 901, wherein the heights of windings 902-905 and core 901 are, for example, along the x-axis. Figure 10 The direction of the z-axis shown is obtained by measurement.
[0063] Figure 11 Examples of embodiments of the present invention are shown. Figure 9 The diagram shows a front perspective view of the inductor assembly 90. Due to the positional relationship between windings 902-905, Figure 11 The diagram shows windings 903 and 902 at the very front, while windings 905 and 904 are located after windings 903 and 902, therefore... Figure 11 It is not visible in the middle.
[0064] To illustrate the direction of current flow, dashed line 43 shows the current flowing through winding 903, for example from the first end 223 to the second end 224 of winding 903. Dotted line 44 shows the current flowing through winding 902, for example from the first end 221 to the second end 222 of winding 902. In the partially overlapping region of windings 902 and 903, the bodies 902-1 of winding 902 and 903-1 partially overlap each other to have currents in opposite directions, thus the magnetic flux z generated by windings 902 and 903 at least partially cancels each other out. The length DOL1 of the partially overlapping region of windings 902 and 903 determines their coupling coefficient, thereby achieving optimal performance. Specifically, the longer the length DOL1, the greater the coupling coefficient between winding 902 and winding 903; conversely, the shorter the length DOL1, the smaller the coupling coefficient between winding 902 and winding 903.
[0065] Figure 12 Examples of embodiments of the present invention are shown. Figure 9 The diagram shows a top perspective view of the inductor assembly 90. Length DOL1 represents the length of the partially overlapping region between windings 902 and 903. Length DOL2 represents the length of the partially overlapping region between windings 904 and 905 and is used to determine the coupling coefficient between windings 904 and 905.
[0066] Figure 13 Examples of embodiments of the present invention are shown. Figure 9 The inductor assembly 90 shown is a side perspective view. Figure 13 The gap GP1 between windings 903 and 902, the gap GP2 between windings 905 and 904, and the gap GP3 between windings 902 and 905 are shown. In one example, both gaps GP1 and GP2 are less than 0.4 mm.
[0067] Gap GP3 also serves as the gap between the first set of anti-coupling windings (i.e., 902, 903) and the second set of anti-coupling windings (i.e., 904, 905). Gap GP1 and GP2 should be smaller than gap GP3. Gap GP3 between windings 902 and 905 is used for decoupling between the first and second sets of anti-coupling windings.
[0068] Figure 14 Examples of embodiments of the present invention are shown. Figure 9 A top view of the inductor assembly 90 shown. Figure 14 In the example, the ends 221-228 of the windings 902-905 are located on the bottom surface 922 of the inductor assembly 90 and play a key role in current flow and power transmission.
[0069] The first end 221 of winding 902 forms a switch pad PSW1 or is electrically connected to the switch pad PSW1, which is electrically connected to the switch node 214 of power chip 210-1. The second end 222 of winding 902 forms an output pad PVO1 or is electrically connected to the output pad PVO1, which is electrically connected to the output voltage node 231 to provide the output voltage VOUT1. The first end 223 of winding 903 forms a switch pad PSW2 or is electrically connected to the switch pad PSW2, which is electrically connected to the switch node 214 of power chip 210-2. The second end 224 of winding 903 forms an output pad PVO2 or is electrically connected to the output pad PVO2, which is electrically connected to the output voltage node 232 to provide the output voltage VOUT2. The first end 225 of winding 904 forms a switch pad PSW3 or is electrically connected to the switch pad PSW3, which is electrically connected to the switch node 215 of power chip 210-1. The second end 226 of winding 904 forms an output pad PVO3 or is electrically connected to the output pad PVO3, which is electrically connected to the output voltage node 233 to provide the output voltage VOUT3. The first end 227 of winding 905 forms a switch pad PSW4 or is electrically connected to the switch pad PSW4, which is electrically connected to the switch node 215 of power chip 210-2. The second end 228 of winding 905 forms an output pad PVO4 or is electrically connected to the output pad PVO4, which is electrically connected to the output voltage node 234 to provide the output voltage VOUT4.
[0070] like Figure 14 As shown, the output pads PVO1 to PVO4 are located in the middle area of the bottom surface 922 of the inductor assembly 90, and not near the edge of the bottom surface 922. Therefore, each pad can use more space, especially the output pads PVO1 to PVO4, which is beneficial for layout and soldering.
[0071] Figure 15 The inductance curves of output inductors 220-1 and 220-2 according to embodiments of the present invention are shown. Figure 15 An example of the inductance curves for output inductors 220-1 and 220-2 is shown. Output inductors 220-3 and 220-4 have similar inductance curves and are therefore not shown for clarity.
[0072] Steady-state equivalent inductance curve 1501 shows the relationship between the equivalent inductance characteristic of output inductor 220-1 and the output current in steady state. Steady-state equivalent inductance curve 1502 shows the relationship between the equivalent inductance characteristic of output inductor 220-2 and the output current in steady state. Transient equivalent inductance curve 1503 shows the relationship between the equivalent inductance characteristic of output inductor 220-1 and the output current in transient state. Transient equivalent inductance curve 1504 shows the relationship between the equivalent inductance characteristic of output inductor 220-2 and the output current in transient state. Steady-state equivalent inductance curves 150 and 1502 are generated based on a four-phase interleaved operation mode, using a pulse width modulation (PWM) drive signal with a 90-degree phase offset. Transient equivalent inductance curves 1503 and 1504 are generated based on a single-phase operation mode, i.e., all phase circuits are simultaneously turned on and off.
[0073] Figure 16 Examples of embodiments of the present invention are shown. Figure 9 The power converter 200 shown has a layout 160. Two power chips 210-1 and 210-2 are placed on opposite sides of the inductor assembly 90. Output pads PVO1 to PVO4 are located in the middle region of the bottom surface 922 of the inductor assembly 90. Figure 16 In the example, current flows from power chip 210-1 to switch pad PSW1 via interconnect 701, current flows from power chip 210-2 to switch pad PSW2 via interconnect 702, current flows from power chip 210-1 to switch pad PSW3 via interconnect 703, and current flows from power chip 210-2 to switch pad PSW4 via interconnect 704. Figure 16 In the example, output pads PVO1 to PVO4 are electrically connected together, for example, via interconnect 705, to provide an output voltage to the load, thereby allowing current to flow from the inductor assembly 90 to the load.
[0074] Although the invention has been described with reference to several exemplary embodiments, it should be understood that the terminology used is descriptive and exemplary, and not restrictive. Since the invention can be embodied in many forms without departing from the spirit or essence of the invention, it should be understood that the above embodiments are not limited to any of the foregoing details, but should be interpreted broadly within the spirit and scope defined by the appended claims. Therefore, all variations and modifications falling within the scope of the claims or their equivalents should be covered by the appended claims.
Claims
1. A power converter, comprising: An inductor assembly comprising two windings sharing a common magnetic core to form a coupled inductor, each winding comprising a body, a first portion, and a second portion, wherein the body of each winding extends toward the top surface of the inductor assembly, the first portion of each winding extends to the bottom surface of the inductor assembly to form a first end of the winding, and the second portion of each winding extends to the bottom surface of the inductor assembly to form a second end of the winding; as well as Two power chips, each power chip including a pair of switches forming a switching node, the switching node being electrically connected to a first end of a corresponding winding, the second end of the corresponding winding being configured to provide an output voltage; in The two windings have a partially overlapping region, which is used to determine the coupling coefficient between the coupled inductors.
2. The power converter as claimed in claim 1, wherein: The first ends of the two windings are located at two opposite edges of the bottom surface of the inductor assembly, the second ends of the two windings are located in the middle area of the bottom surface of the inductor assembly, and the two power chips are placed on opposite sides of the inductor assembly.
3. The power converter of claim 2, further comprising: An interconnection that electrically connects the second ends of the two windings together to provide the output voltage.
4. The power converter as claimed in claim 1, wherein: The main bodies of the two windings are arranged perpendicular to the top and bottom surfaces of the inductor assembly and partially overlap each other to form anti-coupling between the two windings.
5. The power converter as claimed in claim 1, wherein: The first portion of the first winding and the second portion of the second winding extend toward the first side of the magnetic core, and the second portion of the first winding and the first portion of the second winding extend toward the second side of the magnetic core, with the first side and the second side opposite to each other.
6. The power converter as claimed in claim 1, wherein: The gap between the main bodies of the two windings is less than 0.4 mm.
7. A power converter, comprising: An inductor assembly comprising four windings sharing a common magnetic core to form a coupled inductor, each winding comprising a body, a first portion, and a second portion, wherein the body of each winding extends toward the top surface of the inductor assembly, the first portion of each winding extends to the bottom surface of the inductor assembly to form a first end of the winding, and the second portion of each winding extends to the bottom surface of the inductor assembly to form a second end of the winding; as well as Two power chips are placed on opposite sides of the inductor assembly, wherein each power chip includes two pairs of switches, each pair of switches forming a switch node, the switch node being electrically connected to a first end of a corresponding winding, and the second end of the corresponding winding being configured to provide an output voltage.
8. The power converter as claimed in claim 7, wherein: The first overlapping region between the first winding and the second winding is used to determine the coupling coefficient between the first winding and the second winding. as well as The second overlapping region between the third and fourth windings is used to determine the coupling coefficient between the third and fourth windings.
9. The power converter as claimed in claim 8, wherein: The first end of the first winding is electrically connected to a switching node formed by the first pair of switches in the first power chip; The first end of the second winding is electrically connected to a switching node formed by the first pair of switches in the second power chip; The first end of the third winding is electrically connected to a switching node formed by the second pair of switches in the first power chip; as well as The first end of the fourth winding is electrically connected to a switching node formed by the second pair of switches in the second power chip.
10. The power converter of claim 7, wherein: The first ends of the four windings are located at the edge of the bottom surface of the inductor assembly, and the second ends of the four windings are located in the middle region of the bottom surface of the inductor assembly.
11. The power converter of claim 10, further comprising: The interconnection electrically connects the second ends of the four windings together to provide the output voltage.
12. The power converter of claim 7, wherein: The bodies of the first winding and the second winding are perpendicular to the top and bottom surfaces of the inductor assembly and partially overlap each other, thereby forming an anti-coupled relationship between the first winding and the second winding. The main bodies of the third winding and the fourth winding are perpendicular to the top and bottom surfaces of the inductor assembly and partially overlap each other, thereby forming an anti-coupling between the third winding and the fourth winding.
13. The power converter of claim 7, wherein: The first winding and the second winding are placed adjacent to each other to form a first set of anti-coupled windings, and there is a first gap between the main bodies of the first winding and the second winding; as well as The third and fourth windings are placed adjacent to each other to form a second set of anti-coupled windings, and there is a second gap between the main bodies of the third and fourth windings.
14. The power converter of claim 13, wherein: The first gap and the second gap are smaller than the gap between the first set of anti-coupling windings and the second set of anti-coupling windings.
15. The power converter of claim 13, wherein: Both the first gap and the second gap are less than 0.4 mm.
16. An inductor assembly for a power converter, comprising: magnetic core; as well as A first winding and a second winding, wherein the first winding and the second winding share the magnetic core; in Each of the first winding and the second winding includes a body, a first portion, and a second portion, wherein the body of each winding extends toward the top surface of the inductor assembly, the first portion of each winding extends to the bottom surface of the inductor assembly to form a first end of the winding, and the second portion of each winding extends to the bottom surface of the inductor assembly to form a second end of the winding. as well as There is a first partially overlapping region between the first winding and the second winding, which is used to determine the coupling coefficient between the first winding and the second winding.
17. The inductor assembly of claim 16, wherein: The first end of the first winding is electrically connected to the first switch node formed by the first pair of switches; The second end of the first winding is electrically connected to the first output pad; The first end of the second winding is electrically connected to the second switching node formed by the second pair of switches; as well as The second end of the second winding is electrically connected to the second output pad.
18. The inductor assembly of claim 17, wherein: The first ends of the first winding and the second winding are both located at the edge of the bottom surface of the inductor assembly, and the second ends of the first winding and the second winding are both located in the middle region of the bottom surface of the inductor assembly.
19. The inductor assembly of claim 16, further comprising: The third winding and the fourth winding share the same magnetic core; in Each of the third and fourth windings includes a body, a first portion, and a second portion, wherein the body of each winding extends toward the top surface of the inductor assembly, the first portion of each winding extends toward the bottom surface of the inductor assembly to form a first end of the winding, and the second portion of each winding extends toward the bottom surface of the inductor assembly to form a second end of the winding. as well as There is a second overlapping region between the third winding and the fourth winding, which is used to determine the coupling coefficient between the third winding and the fourth winding.
20. The inductor assembly of claim 19, wherein: The first winding and the second winding are placed adjacent to each other to form a first set of anti-coupled windings, and there is a first gap between the main bodies of the first winding and the second winding; The third and fourth windings are placed adjacent to each other to form a second set of anti-coupled windings, and there is a second gap between the main bodies of the third and fourth windings; as well as The first gap and the second gap are smaller than the third gap between the first set of anti-coupling windings and the second set of anti-coupling windings.