Multiphase switching power converters with low magnetic core losses and related methods

Abstract

A method for reducing magnetic core losses in a multi-phase switching power converter including a coupled inductor. The method includes (a) generating a plurality of periodic voltage waveforms, each periodic voltage waveform being applied to a respective one of a plurality of windings of the coupled inductor, and (b) distributing a flux of changing magnetic flux in a magnetic core of the coupled inductor by controlling a phase shift between the plurality of periodic voltage waveforms such that at least two consecutive peak magnitude portions of the plurality of periodic voltage waveforms are not applied to respective ones of the plurality of windings of the coupled inductor that are immediately physically adjacent to one another.

Description

[0001] This application claims the benefit of U.S. Provisional Patent Application No. 63 / 609,226, filed December 12, 2023, and U.S. Non-Provisional Patent Application No. 18 / 966,358, filed December 3, 2024, both of which are incorporated herein by reference. BACKGROUND

[0002] Switching power converters are commonly used in electronic devices, for example, to provide a regulated electrical power source. A switching power converter is designed so that its solid-state power switching devices do not operate continuously in their active state; instead, the power switching devices repeatedly switch between their on and off states. Although switching power converters can achieve high efficiency, particularly under high load conditions, they incur losses due to the repeated switching of switching devices between their on and off states. Such losses, which can be referred to as switching losses, include losses in switching devices as well as losses in other components electrically coupled to the switching devices, such as inductors and capacitors.

[0003] Inductors are often used for energy storage in switching power converters. Some switching power converters have one or more discrete inductors, where a discrete inductor is an inductance that is not magnetically coupled to any other inductor. Other switching power converters have one or more coupled inductors, where a coupled inductor is a device that has two or more magnetically coupled inductors. A coupled inductor has a magnetizing or mutual inductance, which is an inductance associated with the magnetic flux connecting the windings of the coupled inductor. In addition, each winding of a coupled inductor has leakage inductance, which is an inductance associated with a magnetic flux flowing only around the respective winding, i.e.a magnetic flux that is not coupled to any other winding. Coupled inductors are commonly used in multiphase switching power converters, such as a multiphase buck converter, a multiphase boost converter, or a multiphase buck-boost converter, for energy storage and to achieve beneficial coupling between the converter phases. BRIEF DESCRIPTION OF THE DRAWINGS Fig. Figure 1 is an illustration of a discrete inductor showing a magnetic flux flowing through a magnetic core of the discrete inductor. Fig. Figure 2 is an illustration of a coupled inductor showing a magnetic flux flowing through a magnetic core of the coupled inductor. Fig. 3 is a circuit diagram of a multi-phase switching power converter with low magnetic core losses according to one embodiment. Fig. 4 illustrates a possible implementation of switching stages of the multiphase switching power converter of Fig. 3. Fig. 5 is a plan view of a possible embodiment of a coupled inductor of the multiphase switching power converter of Fig. 3. Fig. Figure 6 is a cross-sectional view of the coupled inductance of Fig. 5 along line 6A-6A from Fig. 5. Fig. Figure 7 is a side elevation of the coupled inductance of Fig. 5. Fig. Figure 8 is a cross-sectional view of the coupled inductance of Fig. 5 along line 8A-8A from Fig. 6. Fig. 9 is a circuit diagram of an alternative embodiment of the multiphase switching power converter of Fig. 3 including a coupled inductor with windings arranged in two rows. Fig. 10 is a plan view of a possible embodiment of a coupled inductor of the multiphase switching power converter of Fig. 9. Fig. 11 is a front elevation of the coupled inductance of Fig. 10. Fig. 12 is a side elevation of the coupled inductance of Fig. 10. Fig. 13 is a cross-sectional view of the coupled inductance of Fig. 10 along line 13A-13A from Fig. 11. Fig. 14 is a cross-sectional view of the coupled inductance of Fig. 10 along line 14A-14A from Fig. 10. Fig. 15 is a cross-sectional view of the coupled inductance of Fig. 10 along line 15A-15A from Fig. 10. Fig. 16 is another cross-sectional view of the coupled inductance of Fig. 5 along line 6A-6A from Fig. 5, which is marked to show magnetic core sections between immediately adjacent windings. Fig. 17A includes six graphs illustrating an example of voltage waveforms in one embodiment of the multiphase switching power converter of Fig. 3 illustrate. Fig. 17B includes six graphs showing voltage waveforms under a different driving order than that of the example of Fig. 17A illustrate. Fig. 18A includes six graphs illustrating another example of voltage waveforms in an embodiment of the multiphase switching power converter of Fig. 3 illustrate. Fig. Figure 18B includes six graphs showing voltage waveforms under a different driving order than that of the example of Fig. 18A illustrate. Fig. 19 is a flowchart of a method for reducing magnetic core losses in a multi-phase switching power converter including a coupled inductor, according to one embodiment. Fig. 20 is a cross-sectional view of the coupled inductance of Fig. 5, which is marked to indicate the operation of the multiphase switching power converter of Fig. 3 according to the procedure of Fig. 19 to illustrate. Fig. 21 is a flowchart of another method for reducing magnetic core losses in a multi-phase switching power converter including a coupled inductor, according to one embodiment. Fig. 22 is a cross-sectional view of the coupled inductance of Fig. 5, which is marked to indicate the operation of the multiphase switching power converter of Fig. 3 according to the procedure of Fig. 21 to illustrate. Fig. 23 is a flowchart of another method for reducing magnetic core losses in a multi-phase switching power converter including a coupled inductor, according to one embodiment. Fig. 24 is a cross-sectional view of the coupled inductance of Fig. 5, which is marked to indicate the operation of the multiphase switching power converter of Fig. 3 according to the procedure of Fig. 23 to illustrate. Fig. 25 is a flowchart of another method for reducing magnetic core losses in a multi-phase switching power converter including a coupled inductor, according to one embodiment. Fig. Figure 26 is a cross-sectional view of the coupled inductance of Fig. 10, which is marked to indicate the operation of the multiphase switching power converter of Fig. 9 according to the procedure of Fig. 25 to illustrate. Fig. 27 is a flowchart of another method for reducing magnetic core losses in a multi-phase switching power converter including a coupled inductor, according to one embodiment. Fig. 28 is a flowchart of an additional method for reducing magnetic core losses in a multi-phase switching power converter including a coupled inductor, according to one embodiment. Fig. Figure 29 is a block diagram of one possible embodiment of a controller that may be configured to achieve a desired order of driving phases. Fig. 30 is a block diagram illustrating an example of how a desired order of driving phases may be achieved when using a fixed drive order controller, according to one embodiment. Fig. 31 is a circuit diagram of an alternative embodiment of the multiphase switching power converter of Fig. 3, which is designed to have a boost conversion topology. Fig. 32 is a circuit diagram of an alternative embodiment of the multiphase switching power converter of Fig. 3, which is designed to have a buck-boost topology. Fig. 33 is a circuit diagram of an alternative embodiment of the multiphase switching power converter of Fig. 3, which is designed to receive power from multiple input power nodes and supply power to multiple output power nodes. Fig. 34 illustrates another possible implementation of switching stages of the multiphase switching power converter of Fig. 3. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0004] An inductor includes one or more windings and a magnetic core. The magnetic core is formed of a magnetic material, such as a magnetic ferrite material, a magnetic composite material, and / or a magnetic powder iron material. Current flowing through a winding generates a magnetic flux, and the magnetic core provides a low-reluctance path for the magnetic flux. A changing magnitude of the magnetic flux flowing through the magnetic core, caused, for example, by a changing magnitude of the current flowing through the winding, causes losses in the magnetic core, typically referred to as core losses.

[0005] For example, Fig. 1 is an illustration of a discrete inductor 100 including a magnetic core 102 and a winding 104. The magnetic core 102 forms a gap 106, and the winding 104 is wound around a portion of the magnetic core 102 referred to as a winding post 108. Fig. 1 illustrates a voltage V applied to the winding 104, which causes a current / to flow through the winding 104. The current I flowing through the winding 104 generates a magnetic flux 110 that flows through the magnetic core 102, wherein the magnetic flux 110 is Fig. 1 is shown symbolically by several line segments.

[0006] Core losses in a unit volume 112 of the magnetic core 102 can be approximated using Eq. 1 below, assuming that the magnetic flux density in the unit volume 112 is substantially uniform, where (a) P v_112core losses in unit volume 112, (b) B is a changing magnitude of the density of magnetic flux 110 in unit volume 112, (c) f is the frequency of a changing current I in winding 104 associated with a changing magnitude of the density of magnetic flux 110, (d) and k, α and β are Steinmetz coefficients that are a function of, for example, the composition of magnetic core 102, the temperature of magnetic core 102, the magnitude of current I in winding 104, and the shape of current I in winding 104. Importantly, the coefficient β is typically in the range of approximately 2.4 to 3.4, and core losses in magnetic core 102 are therefore highly nonlinear. Therefore, core losses increase exponentially with increasing changing magnitude of the density of magnetic flux 110, and a small increase in the changing density of magnetic flux 110 can therefore cause a large increase in core losses.Therefore, it is desirable that the changing magnitude of the density of the magnetic flux 110 be small to promote low core losses in the magnetic core 102. Pv_112=k⋅β⋅fα⋅Bβ

[0007] Core losses can be particularly acute in a coupled inductor due to the possibility of high magnetic flux density resulting from a current flowing through two or more windings simultaneously. For example, Fig. 2 illustrates a coupled inductor 200 including a magnetic core 202, a first winding 204, and a second winding 206. The magnetic core 202 forms a gap 208, the first winding 204 is wound around a first winding post 210 of the magnetic core 202, and the second winding 206 is wound around a second winding post 212 of the magnetic core 202. Fig. 2 illustrates a varying voltage V1 applied to the first winding 204, which causes a varying current I1 to flow through the first winding 204. Furthermore, Fig. 2 a changing voltage V2 applied to the second winding 206, which causes a changing current I2 to flow through the second winding 206. The current I1 flowing through the first winding 204 generates a first magnetic flux 214 flowing through the magnetic core 202, wherein the first magnetic flux 214 in Fig. 2 is symbolically shown by several solid line segments. In addition, the current I2 flowing through the second winding 206 generates a second magnetic flux 216 flowing through the magnetic core 202, wherein the second magnetic flux 216 is Fig. 2 is symbolically shown by several dashed line segments. These fluxes are associated with magnetic leakage fluxes in the first and second windings, both of which pass into a unit volume 218 of the common leakage leg of the core, and mutual magnetic fluxes associated with the first winding 204 and the second winding 206 are in Fig. 2 not shown for the sake of clarity of illustration.

[0008] Both the first magnetic flux 214 and the second magnetic flux 216 flow through certain parts of the magnetic core 202, such as a unit volume 218 of the magnetic core 202. Assuming that changing currents I1 and I2 have a common frequency and phase and the intensity of the magnetic flux in the unit volume 218 of the magnetic core 202 is approximately uniform, core losses in the unit volume 218 can be approximated using Eq. 2 below, where (a) Pv_218Core losses in unit volume 218, (b) k, α, and β are the same as discussed above with reference to Equation 1, (c) B1 is the varying magnitude of the density of the first magnetic flux 214 in unit volume 218, (d) B2 is the varying magnitude of the density of the second magnetic flux 216 in unit volume 218, and (e) f is the frequency of each of the varying currents I1 and I2. As discussed above, the coefficient β typically ranges from approximately 2.4 to 3.4, and core losses in unit volume 218 of the magnetic core 202 are therefore greater than the sum of respective core losses from each varying current I1 and current I2. Consequently, driving the first winding 204 and the second winding 206 in a manner that causes a high dynamic flux density in the magnetic core 202 can result in very high core losses.In this simplified example, it is assumed that the flux densities change in the same direction with the same timing and that the changing flux densities are completely additive. However, it is possible to change the phase relationship between the changing flux densities so that they are at least partially subtractive. Pv_218=k⋅β⋅fα⋅(B1+B2)β

[0009] Disclosed herein are multi-phase switching power converters with low core losses and associated methods that help minimize core losses caused by a high changing magnetic flux density in a magnetic core, such as by spreading the flow of a changing magnetic flux in the magnetic core to help minimize a changing peak magnetic flux density in the magnetic core.For example, certain embodiments of the novel multi-phase switching power converters and related methods control phases of a multi-phase switching power converter to generate periodic voltage waveforms applied to windings of a coupled inductor with phase shift between the voltage waveforms such that at least two consecutive peak magnitude portions of the plurality of periodic voltage waveforms are not applied to respective windings that are immediately physically adjacent to each other. For example, in some embodiments, at least some phases with respective windings that are immediately physically adjacent to each other in the coupled inductor are not sequentially driven to help separate, within a magnetic core, respective changing magnetic fluxes of sequentially driven phases.This type of phase control helps to physically separate high-harmonic voltage waveforms and high-slew-rate current waveforms in the coupled inductor, helping to minimize high magnetic flux density with a high rate of change in a magnetic core of the coupled inductor. This helps to avoid large core losses resulting from the typically highly nonlinear relationship between changing magnetic flux density and magnetic core losses. Accordingly, the new multiphase switching power converters and related methods promote efficient operation of multiphase switching power converters. Furthermore, the new multiphase switching power converters and related methods can reduce the potential for magnetic core saturation by helping to prevent high magnetic flux density in a magnetic core of a coupled inductor.Furthermore, the reduced potential for saturation potentially achieved by the new multiphase switching power converters and related techniques may allow a reduction in switching frequency, as larger peak currents and larger imbalances between phases may be acceptable given the reduced potential for magnetic saturation.

[0010] Fig. 3 is a circuit diagram of a multiphase switching power converter 300, which is one embodiment of the novel multiphase switching power converters disclosed herein. The multiphase switching power converter 300 includes N phases 302, a controller 304, and one or more optional output capacitors 306, where N is an integer greater than or equal to four. Throughout this document, specific instances of an element may be referenced using a number in parentheses (e.g., phase 302(1)), while numbers without parentheses refer to any such element (e.g., phases 302). Each phase 302 includes a switching stage 308 electrically coupled to a winding 310 at a switching node X. While Fig. 3 indicates that N is greater than four, it is understood that N could be equal to four.

[0011] Each winding 310 is electrically coupled between the switching node X of its respective phase 302 and a common output power node 312. For example, winding 310(1) is electrically coupled between the switching node X(1) and the output power node 312, and winding 310(2) is electrically coupled between the switching node X(2) and the output power node 312. The output power node 312 has a voltage V o relative to a reference node 314, and an output current I o flows to a load (not shown) that is electrically coupled to the output power node 312. The output current I ocould have a negative polarity without departing from the scope of the present invention. One or more output capacitors 306 are optionally electrically coupled between the output power node 312 and the reference node 314. The reference node 314 is illustrated as a ground node, such as a ground node or a chassis ground node. However, it should be understood that the reference node 314 need not be a ground node, and accordingly, the reference node 314 could be at an electrical potential other than a ground or chassis ground.

[0012] Each switching stage 308 is configured to repeatedly switch the switching node X of its phase 302 between an input power node 316 and a reference node 314 in response to control signals U and L generated by the controller 304, thereby generating a voltage waveform V w, e.g., a square wave voltage waveform, is generated at its respective winding 310. Connections between the controller 304 and switching stages 308 are not shown for clarity of illustration, although it is understood that one or more communication buses may communicatively couple the control signals U and L from the controller 304 to the switching stages 308. The switching stage 308(1) is configured to repeatedly switch node X(1) between the input power node 316 and the reference node 314 in response to control signals U(1) and L(1) to generate a voltage waveform V w (1) at the winding 310(1), the switching stage 308(2) is configured to repeatedly switch the node X(2) between the input power node 316 and the reference node 314 in response to control signals U(2) and L(2) to generate a voltage waveform V w(2) at the winding 310(2), etc. The input power node 316 is at a voltage V in relative to the reference node 314, and each switching stage 308 accordingly switches the node X of its phase 302 repeatedly between the voltage V in and zero volts relative to the reference node 314. An input current I in flows from an electrical power source (not shown) via the input power node 316 to the multiphase switching power converter 300. The input current I in could have a negative polarity without departing from the scope of the present invention. One or more input capacitors (not shown) are optionally electrically coupled between the input power node 316 and the reference node 314.

[0013] In this document, a phase of a multi-phase switching power converter is "driven" by initiating a switching cycle of the phase, such as by connecting a switching node of the phase to a node, e.g., to a power node or to a reference node. For example, in the case of multi-phase switching power converter 300, a phase 302 is "driven" by its respective switching stage 308 connecting its respective switching node X to the input power node 316. For example, phase 302(1) is "driven" by switching stage 308(1) connecting switching node X(1) to the input power node 316, e.g., by switching stage 308(1) changing its operating state such that switching node X(1) is connected to the input power node 316 instead of being connected to the reference node 314.As another example, phase 302(2) is driven by switching stage 308(2) connecting switching node X(2) to input power node 316, e.g., by switching stage 308(2) changing its operating state such that switching node X(2) is connected to input power node 316 instead of being connected to reference node 314. As discussed below, certain embodiments of multi-phase switching power converter 300 are configured such that controller 304 controls phases 302 such that phases 302 are driven out of phase, that is, such that each phase 302 is driven at a different time.

[0014] Fig. Figure 4 illustrates a possible implementation of the switching stages 308 of the multiphase switching power converter 300. In particular, Fig. 4 is a circuit diagram of N switching stages 402, wherein the switching stages 402 are an embodiment of the switching stages 308 of Fig. 3. Each switching stage 402 includes an upper switching device 404 and a lower switching device 406. Each upper switching device 404 is electrically coupled between the input power node 316 and the switching node X of its respective phase 302. Each lower switching device 406 is electrically coupled between the switching node X of its respective phase 302 and the reference node 314. For example, the upper switching device 406(1) is electrically coupled between the input power node 316 and the switching node X(1), and the lower switching device 406(1) is electrically coupled between the switching node X(1) and the reference node 314. Each upper switching device 404 switches in response to a respective control signal U from the controller 304, and each lower switching device 406 switches in response to a respective control signal L from the controller 304.For example, in some embodiments, each upper switching device 404 operates in its on (conductive) state when its respective control signal U is asserted, and the switching device operates in its off (non-conductive) state when its respective control signal U is asserted. Likewise, in some embodiments, each lower switching device 406 operates in its on (conductive) state when its respective control signal L is asserted, and the switching device operates in its off (non-conductive) state when its respective control signal L is asserted. Each switching device 404 and 406 includes, for example, one or more transistors.

[0015] Again with reference to Fig. 3, the windings 310 are magnetically coupled by a magnetic core 318. Furthermore, the magnetic core 318 provides a magnetic leakage flux path for each winding 310. The windings 310 and the magnetic core 318 are part of a coupled inductor 320. The magnetic core 318 is made of, for example, a magnetic ferrite material and / or a magnetic iron powder material. In this document, two windings of a coupled inductor are immediately physically adjacent to each other if no other windings of the coupled inductor are located between the two windings. For example, Fig. 3 brackets 322 indicating windings 310 that are immediately physically adjacent to each other in the coupled inductor 320, where two windings 310 are immediately physically adjacent to each other if there is no intervening winding 310 between the two windings. In particular, bracket 322(1) indicates that windings 310(1) and 310(2) are immediately physically adjacent to each other, bracket 322(2) indicates that windings 310(2) and 310(3) are immediately physically adjacent to each other, etc. Conversely, the absence of a bracket 322 between two windings 310 in Fig. 3 indicates that the two windings are not immediately physically adjacent to each other, or in other words, that one or more other intermediate windings 310 are located between the two windings in the coupled inductance 320. For example, Fig. 3 no clamp 322 connecting the windings 310(1) and 310(3), and thus the windings 310(1) and 310(3) are not immediately physically adjacent to each other, or in other words, the absence of a clamp connecting the windings 310(1) and 310(3) means that there is at least one intermediate winding 310 between the windings 310(1) and 310(3).

[0016] The coupled inductor 320 may have essentially any configuration as long as (a) at least two windings 310 are immediately physically adjacent to each other and (b) at least two windings 310 are not immediately physically adjacent to each other. A discussion of one possible embodiment of the coupled inductor 320 follows with reference to Fig. 5-8. However, it should be understood that the coupled inductor 320 may be implemented in other ways without departing from the scope of the present invention.

[0017] Fig. Figure 5 is a top view of a coupled inductor 500, which is an embodiment of the coupled inductor 320, where N is equal to six. Fig. 6 is a cross-sectional view of the coupled inductor 500 taken along line 6A-6A of Fig. 5 and Fig. 7 is an elevation view of one side 502 of the coupled inductor 500 (see Fig. 5 for an identification of page 502). Fig. 8 is a cross-sectional view of the coupled inductor 500 taken along line 8A-8A of Fig. 6. The coupled inductor 500 includes a magnetic core 504 and N windings 506. The magnetic core 504 is an embodiment of the magnetic core 318, and the magnetic core 504 includes a first rail 508, a second rail 510, N winding posts 512, a first magnetic flux transfer element 514, and a second magnetic flux transfer element 516, each of the aforementioned elements of the magnetic core 504 being formed from a magnetic material, such as a magnetic ferrite material and / or a magnetic iron powder material. The first rail 508 and the second rail 510 are separated from each other in a direction 518, and each of the N winding posts 512 is disposed between the first rail 508 and the second rail 510 in the direction 518. In addition, each of the N winding posts 512 is separated from each other of the N winding posts 512 in a direction 520, wherein the direction 520 is orthogonal to the direction 518.Accordingly, the magnetic core 504 has a conductor configuration.

[0018] The first magnetic leakage flux transmission element 514 is arranged on the first rail 508 in a direction 522 that is orthogonal to each of the directions 518 and 520, and a second magnetic leakage flux transmission element 516 is arranged on the second rail 510 in the direction 522. The first magnetic leakage flux transmission element 514 and the second magnetic leakage flux transmission element 516 extend toward each other in the direction 518, although the first magnetic leakage flux transmission element 514 and the second magnetic leakage flux transmission element 516 are separated in the direction 518 by a gap 524 filled with air, paper, plastic, or a magnetic material with a lower magnetic permeability than the magnetic material forming the first magnetic leakage flux transmission element 514 and the second magnetic leakage flux transmission element 516.As discussed in more detail below, the first magnetic flux leakage transfer element 514 and the second magnetic flux leakage transfer element 516 together provide a path through which magnetic leakage flux can flow within the magnetic core 504. The magnetic core 504 optionally forms one or more additional spaces (not shown), such as spaces filled with air, paper, plastic, or a magnetic material with a lower magnetic permeability than the magnetic material forming the winding posts 512, along a path of magnetic flux traveling across the winding posts 512 between the first rail 508 and the second rail 510.

[0019] The windings 506(1)-506(6) are each an embodiment of the windings 310(1)-310(6) of Fig. 3. A respective winding 506 is wound around each winding post 512. In this document, a winding wound around a winding post need not be completely wound around the winding post. Although each winding 506 is illustrated as a single-turn winding formed from electrically conductive foil, such as copper foil, the configurations of the windings 506 may vary. For example, one or more of the windings 506 may form multiple turns, and / or one or more of these windings may be formed from a single wire or a stranded wire instead of an electrically conductive foil.

[0020] The windings 506 are arranged in a common row 526 in the coupled inductor 500, with the row 526 extending in the direction 520. Fig. 8 includes brackets 528 indicating windings 506 that are immediately physically adjacent to each other in the coupled inductor 500. Specifically, bracket 528(1) indicates that windings 506(1) and 506(2) are immediately physically adjacent to each other, bracket 528(2) indicates that windings 506(2) and 506(3) are immediately physically adjacent to each other, bracket 528(3) indicates that windings 506(3) and 506(4) are immediately physically adjacent to each other, bracket 528(4) indicates that windings 506(4) and 506(5) are immediately physically adjacent to each other, and bracket 528(5) indicates that windings 506(5) and 506(6) are immediately physically adjacent to each other. Conversely, the absence of a clamp 528 between two windings 506 in Fig. 8 indicates that the two windings are not immediately physically adjacent to each other. For example, windings 506(1) and 506(3) are not immediately physically adjacent to each other because winding 506(2) is located between windings 506(1) and 506(3) in direction 520. As another example, windings 506(1) and 506(4) are not immediately physically adjacent to each other because two windings, i.e., windings 506(2) and 506(3), are located between windings 506(1) and 506(4) in direction 520.

[0021] The first magnetic leakage flux transmission element 514 and the second magnetic leakage flux transmission element 516 are each shared by all windings 506. In particular, the first magnetic leakage flux transmission element 514 and the second magnetic leakage flux transmission element 516 together form part of a magnetic leakage flux path for each winding 506. For example, Fig. 7 shows a possible magnetic flux leakage path 702 for the winding 506(1). The path 702 includes the winding post 512(1) (under the winding 506(1) and therefore in Fig. 7), the first rail 508, the first magnetic leakage flux transfer element 514, the gap 524, the second magnetic leakage flux transfer element 516, and the second rail 510, wherein the direction of magnetic leakage flux movement along path 702 depends on the direction of current flow in the winding 506(1). It is understood that every other winding 506 has a magnetic leakage flux path analogous to that of path 702, but with the winding post 512(1) replaced by the respective winding post 512 for the winding 506. The leakage inductance of the windings 506 can be adjusted during the design of the coupled inductor 500, for example, by varying the thickness of the gap 524 in the direction 518.

[0022] The coupled inductor 500 could be modified to include additional or fewer winding posts 512 and windings 506 such that N is a positive integer other than six. Furthermore, the coupled inductor 500 could be modified in other ways without departing from the scope of the present invention. For example, the magnetic core 504 could be modified to replace the first magnetic flux transfer element 514 and the second magnetic flux transfer element 516 with one or more other magnetic flux transfer elements for controlling the leakage inductance of the windings 506. As another example, the magnetic core 504 could be modified to minimize the leakage inductance by omitting the first magnetic flux transfer element 514 and the second magnetic flux transfer element 516.As an additional example, the coupled inductor 500 could be modified to include a boost winding that is magnetically coupled to all N windings 506.

[0023] Again with reference to Fig. 3, the brackets 322 assume that all windings 310 are arranged in a common row in the coupled inductor 320. However, the coupled inductor 320 could alternatively be configured to include at least two rows of windings 310, such that the windings 310 can be immediately adjacent in two dimensions. Furthermore, the coupled inductor 320 could alternatively be configured to include at least two rows and one or more columns of windings 310, such that the windings 310 can be immediately adjacent in three dimensions.

[0024] For example, Fig. 9 is a circuit diagram of a multiphase switching power converter 900, which is an alternative embodiment of the multiphase switching power converter 300 ( Fig. 3) in which the coupled inductor 320 is replaced by a coupled inductor 920. N is equal to six in the illustrated embodiment of the multi-phase switching power converter 900, although it is understood that N could have a different value without departing from the scope of the present invention. The coupled inductor 920 differs from the coupled inductor 320 in that the magnetic core 318 is replaced by a magnetic core 918. Unlike the magnetic core 318, the magnetic core 918 includes two rows of winding posts (not shown), such that the windings 310 are arranged in two rows, i.e., a row 924 and a row 926.

[0025] The following is a discussion of a possible embodiment of the coupled inductor 920 with reference to Fig. 10-15. However, it should be understood that the coupled inductor 920 may be implemented in other ways without departing from the scope of the present invention.

[0026] Fig. 10 is a top view of a coupled inductor 1000, which is an embodiment of the coupled inductor 920. Fig. 11 is an elevational view of a front side 1002 of the coupled inductor 1000 and Fig. 12 is an elevation of one side 1004 of the coupled inductor 1000 (see Fig. 10 for identification of the front 1002 and the side 1004). Fig. 13 is a cross-sectional view of the coupled inductor 1000 taken along line 13A-13A of Fig. 11, Fig. 14 is a cross-sectional view of the coupled inductor 1000 taken along line 14A-14A of Fig. 10 and Fig. 15 is a cross-sectional view of the coupled inductor 1000 taken along line 15A-15A of Fig. 10. The coupled inductor 1000 includes a magnetic core 1006 and N windings 1008. The magnetic core 1006 is an embodiment of the magnetic core 918, and the magnetic core 1006 includes a first rail 1010, a second rail 1012, N winding posts 1014, and a magnetic flux leakage transfer element 1015, wherein each of the aforementioned elements of the magnetic core 1006 is formed from a magnetic material, such as a magnetic ferrite material and / or a magnetic iron powder material. The first rail 1010 and the second rail 1012 are separated from each other in a direction 1016, and each of the N winding posts 1014 is arranged between the first rail 1010 and the second rail 1012 in the direction 1016.Furthermore, each of the N winding posts 1014 is separated from each other of the N winding posts 1014 in a direction 1018 and in a direction 1020, where direction 1018 is orthogonal to direction 1016 and direction 1020 is orthogonal to each of directions 1016 and 1018. The magnetic core 1006 optionally forms one or more spaces (not shown), such as spaces filled with air, paper, plastic, or a magnetic material having a lower magnetic permeability than the first rail 1010, the second rail 1012, and the magnetic material forming the N winding posts 1014, along the winding posts 1014.

[0027] The magnetic leakage flux transmission element 1015 is arranged in direction 1016 on the first rail 1010 and extends in direction 1016 to the second rail 1012. The magnetic leakage flux transmission element 1015 is separated from the second rail 1012 in direction 1016 by a gap 1021. The gap 1021 is filled, for example, with air, plastic, paper, or a magnetic material with a lower magnetic permeability than the magnetic material forming the magnetic leakage flux transmission element 1015. As discussed in more detail below, the magnetic leakage flux transmission element 1015 provides a path through which magnetic leakage flux can flow within the magnetic core 1006.

[0028] The windings 1008(1)-1008(6) are each an embodiment of the windings 310(1)-310(6) of Fig. 9. A respective winding 1008 is wound around each winding post 1014. Although each winding 1008 is illustrated as a single-turn winding formed from electrically conductive foil, such as copper foil, the configurations of the windings 1008 may vary. For example, one or more of the windings 1008 may form multiple turns, and / or one or more of these windings may be formed from a single wire or a stranded wire instead of an electrically conductive foil.

[0029] As in Fig. 13, the windings 1008 are arranged in two rows, ie rows 1024 and 1026, the embodiments of rows 924 and 926, respectively, of Fig. 9. Accordingly, the windings 1008 can be directly adjacent to each other in two dimensions, ie in the direction 1018 and in the direction 1020. Fig. 13 includes arrows indicating immediately physically adjacent windings 1008. For example, winding 1008(1) is immediately physically adjacent to each of windings 1008(2) and 1008(4), as indicated by respective arrows between winding 1008(1) and each of windings 1008(2) and 1008(4). As another example, winding 1008(2) is immediately physically adjacent to each of windings 1008(1), 1008(3), and 1008(5), as indicated by respective arrows between winding 1008(2) and each of windings 1008(1), 1008(3), and 1008(5).

[0030] The magnetic leakage flux transmission element 1015 is shared by all windings 1008. In particular, the magnetic leakage flux transmission element 1015 forms part of a magnetic leakage flux path for each winding 1008. For example, Fig. 12 a possible magnetic flux leakage path 1202 for the winding 1008(3). The path 1202 includes the winding post 1014(3) (under the winding 1008(3) and therefore in Fig. 12), the first rail 1010, the magnetic flux transfer element 1015, the gap 1021, and the second rail 1012, wherein the direction of magnetic flux movement along path 1202 depends on the direction of current flow in winding 1008(3). It should be understood that every other winding 1008 has a magnetic flux path analogous to that of path 1202, but with winding post 1014(3) replaced by the respective winding post 1014 for winding 1008. The leakage inductance of the windings 1008 can be adjusted during the design of the coupled inductor 1000, for example, by varying the thickness of the gap 1021 in the direction 1016. The configuration of the magnetic flux leakage transfer element 1015 can be varied without departing from the scope of the present invention.For example, the position of the magnetic leakage flux transmission element 1015 in the magnetic core 1006 may vary, the magnetic leakage flux transmission element 1015 may be replaced by two or more magnetic leakage flux transmission elements in the magnetic core 1006, etc. Furthermore, the magnetic leakage flux transmission element 1015 may be omitted from the magnetic core 1006 without departing from the scope of the present invention.

[0031] With further reference to Fig. 3, the controller 304 is implemented, for example, by analog and / or electronic circuitry. In some embodiments, the controller 304 is implemented at least partially by a processor (not shown) that executes instructions in the form of software and / or firmware stored in a memory (not shown). Although the controller 304 is depicted as a discrete element, for simplicity of illustration, the controller 304 may be partially or fully integrated into one or more other elements of the multiphase switching power converter 300. For example, some subsystems of the controller 304 could be integrated into the switching stages 308. Furthermore, Fig. 3 is not intended to require a separate communication bus for each control signal. For example, the controller 304 could be implemented by a combination of a central integrated circuit and local control logic integrated within each switching stage 308, with a single communication bus extending from the central integrated circuit to each switching stage 308. Furthermore, the controller 304 may include multiple components that need not be co-encapsulated or co-located.

[0032] The controller 304 is configured to generate control signals U and L to control the duty cycle (D) of the phase 302, where the duty cycle is a portion of a switching cycle of each phase 302 of the multi-phase switching power converter 300 for which the winding 310 of the phase 302 is driven high, i.e., when the switching node X of the phase 302 is connected to the input power node 316, to regulate at least one parameter of the switching power converter 300. In some embodiments, the controller 304 is configured to control the duty cycle of the phases 302 using pulse width modulation (PWM) and / or pulse frequency modulation (PFM). Examples of possible regulated parameters include, but are not limited to, the magnitude of the input voltage V in, the size of the input current I in , the magnitude of the output voltage V oand the magnitude of the output current 1". For example, in some embodiments, the controller 304 is configured to generate control signals U and L to control the magnitude of the output voltage V o to regulate, and the controller 304 accordingly generates control signals U and L during the continuous conduction operation of the multi-phase switching power converter 300, so that the duty cycle of the phases 302 is equal to a ratio of the output voltage magnitude V o divided by the input voltage V in For example, if the output voltage V o to be regulated to two volts and the input voltage V inis eight volts, generate control signals U and L such that the duty cycle of phases 302 is 0.25. Controller 304 is optionally configured to generate control signals U and L such that phases 302 switch out of phase with each other. For example, in some embodiments, controller 304 is configured to generate control signals U and L such that each phase 302 switches 360 / N degrees out of phase with an adjacent phase 302 in the phase domain.

[0033] Importantly, the multiphase switching power converters 300 and 900 are designed to control the phases 302 to generate periodic voltage waveforms V w with a phase shift between the voltage waveforms V w such that at least two consecutive peak magnitude sections of voltage waveforms V wnot be applied to respective windings 310 that are immediately physically adjacent to each other in the coupled inductor 320 or 920. The multiphase switching power converters 300 and 900 generate periodic voltage waveforms V w in such a way, for example, by controlling the phases 302 such that at least some phases having respective immediately physically adjacent windings 310 in the coupled inductor 320 or 920 are not driven sequentially. However, it should be noted that while the drive time of the phase 302 is a convenient reference point for determining the phase shift between the periodic voltage waveforms V w can be any other time in the periodic voltage waveforms V w can be used as a reference point to determine the phase shift between the periodic voltage waveforms, as long as in each periodic voltage waveform Vw the same time is used.

[0034] Such control of the phases 302 advantageously contributes to minimizing the changing magnetic flux density in the magnetic core 318 or 918 by promoting physical separation of the windings 310 that simultaneously conduct current at a high slew rate, thereby distributing changing magnetic flux within the magnetic core 318 or 918, which helps to minimize the summation of the respective changing magnetic flux generated by two or more windings 310 in the magnetic core 318 or 918. For example, consider Fig. 16, which is another cross-sectional view of the coupled inductor 500 taken along line 6A-6A of Fig. 5 is. Fig. 16 is labeled to show portions 1602 of the magnetic core 504 located between immediately adjacent windings 506. By controlling the phases 302 such that at least two consecutive peak magnitude portions of the voltage waveforms V ware not applied to respective windings 506 that are immediately physically adjacent, the flow of the changing magnetic flux is distributed in the magnetic core 504, helping to reduce the summation of the changing magnetic flux density, for example, in regions 1602 of the magnetic core. As one example, controlling the phases 302 such that immediately physically adjacent windings 506(1) and 506(2) are not driven sequentially helps prevent summation of the respective changing magnetic leakage flux of the windings 506(1) and 506(2) in region 1602(1) of the magnetic core 504. As another example, controlling the phases 302 such that immediately physically adjacent windings 506(2) and 506(3) are not driven sequentially helps prevent summation of the respective changing magnetic leakage flux of the windings 506(2) and 506(3) in region 1602(2) of the magnetic core 504.Accordingly, the novel multiphase switching power converters disclosed herein promote low core losses as well as low susceptibility to magnetic core saturation by helping to control the flow of changing magnetic flux associated with peak magnitude portions of the voltage waveforms V. w It should be noted that the regions 1602 also include portions of the opposite second rail 510 and the opposite second magnetic flux transmission element 516, which in the cross-sectional view of Fig. 16 are not visible.

[0035] Fig. 17A and Fig. 18A, discussed below, illustrate two examples of switching waveforms in one embodiment of the multi-phase switching power converter 300 configured to control the phases 302 such that at least two consecutive peak magnitude portions of the voltage waveforms V wnot be applied to respective windings 310 that are immediately physically adjacent. However, it should be understood that the switching power converter 300 is not limited to, according to the example of Fig. 17A and Fig. 18A to work.

[0036] Fig. Figure 17A includes six graphs 1702, 1704, 1706, 1708, 1710, and 1712 of voltage as a function of time. Graphs 1702, 1704, 1706, 1708, 1710, and 1712 each illustrate examples of voltage waveforms V w (1), V w (2), V w (3), V w (4), V w (5) and V w (6) in one embodiment of the multiphase switching power converter 300, where N=6, V in =12 volts, V o =4 volts and each voltage waveform V w is a square wave. Graphs 1702, 1704, 1706, 1708, 1710, and 1712 have a common time base. In the examples of Fig. 17A, it is assumed that the multiphase switching power converter 300 operates in a steady-state mode, such that the duty cycle of the phases 302 does not vary from one switching cycle to the next. Accordingly, the voltage waveforms V w periodic. Each voltage waveform V w has a period T corresponding to one switching cycle of its respective phase 302. In this example, the controller 304 controls switching stages 308 so that the voltage waveforms V w are phase-shifted to each other. In particular, the activation of successive phases 302 is offset by a time period Φ, where Φ is equal to T / N (and N in the example of Fig. 17A is equal to 6). Consequently, switching cycles of phases 302 each begin at different times. For example, respective switching cycles of phases 302(1), 302(2), 303(3), 303(4), 303(5), and 303(6) shown in Fig. 17A, at times t0, t3, t1, t4, t2 and t5, respectively.

[0037] Each voltage waveform V w includes a respective peak size section t p and a respective non-peak size interval t n in each period T of the voltage waveform. Each peak magnitude interval t p a given voltage waveform V w is a portion of the voltage waveform in which the magnitude of the voltage across its respective winding 310 is at a maximum value during the period T of the voltage waveform. Conversely, each non-peak magnitude portion t n a given voltage waveform V w a portion of the voltage waveform in which the magnitude of the voltage across its respective winding 310 is not at a maximum value during the period T of the voltage waveform. Accordingly, in each period T of a given voltage waveform, V wthe magnitude of the voltage waveform in the peak magnitude section t p of the voltage waveform is larger than in the non-peak magnitude section t n the voltage waveform. For example, in the example of Fig. 17A each tip size section t p a given voltage waveform V w a size V p of eight volts, while each non-peak magnitude section t n a given voltage waveform V w a size V n of four volts. In some alternative embodiments of the multiphase switching power converter 300, the switching stages 308 are modified so that each voltage waveform V w has two or more different non-peak magnitude values ​​in a given switching cycle T of a respective phase 302.

[0038] The controller 304 is designed to control phases in the example of Fig. 17A in the following repeating sequence: Phase 302(1), Phase 302(3), Phase 302(5), Phase 302(2), Phase 302(4), and Phase 302(6). As a result, there is a phase shift among the voltage waveforms V w so that successive peak magnitude intervals t p the voltage waveforms V w not be applied to windings 310 that are immediately physically adjacent to each other in the coupled inductance 320. For example, the peak magnitude sections t p (1) and t p (3) consecutive, ie the peak magnitude interval t p (3) is the first peak magnitude interval that follows the peak magnitude interval t p (1) occurs. Successive peak magnitude intervals t p (1) and t p (3) are not applied to immediately physically adjacent windings 310 in the coupled inductor 320. Instead, the peak magnitude section t p(1) is applied to the winding 310(1), and the peak magnitude section t p (3) is applied to the winding 310(3), wherein the windings 310(1) and 310(3) are not directly physically adjacent to each other, as in Fig. 3 by the absence of a clamp 322 between the two windings. As another example, the peak size sections t p (3) and t p (5) consecutive, ie the peak magnitude section t p (5) is the first peak magnitude interval that follows the peak magnitude interval t p (3) occurs. Successive peak magnitude intervals t p (3) and t p (5) are not applied to immediately physically adjacent windings 310 in the coupled inductor 320. Instead, the peak magnitude section t p (3) is applied to the winding 310(3), and the peak magnitude section t p(5) is applied to the winding 310(5), wherein the windings 310(3) and 310(5) are not directly physically adjacent to each other, as in Fig. 3 by the absence of a clamp 322 between the two windings.

[0039] In a given period T of a phase 302, the peak magnitude section t p a higher harmonic content of the voltage waveform V w as the non-peak size interval t n occurs because the duration of the peak magnitude section t p less than the duration of the non-peak magnitude section t n Furthermore, in a given period T of a phase 302, the fact that a ratio of the voltage magnitude over time in the peak magnitude section t p larger than in the non-peak size section t n is that the rate of increase of the winding current I w (see Fig. 3) in the peak size section t plarger than in the non-peak size section t n Both the high harmonic content of the voltage waveform V w as well as the high rate of increase of the winding current I w are associated with high losses in the magnetic core 318. Accordingly, physically separating successive peak size sections t p in the coupled inductor 320, such as using the method described in Fig. 17A illustrated the control sequence of the phases 302, low losses in the magnetic core 318.

[0040] For comparison, consider Fig. 17B, ​​which includes graphs 1714, 1716, 1718, 1720, 1722, and 1724, which are analogous to graphs 1702, 1704, 1706, 1708, 1710, and 1712, respectively, but assuming that phases 302 are controlled in the following repeating sequence: phase 302(1), phase 302(2), phase 302(3), phase 302(4), phase 302(5), and phase 302(6). As can be seen from Fig. As can be seen in Figure 17B, successive peak magnitude intervals t p the voltage waveforms V w applied to windings 310 that are physically adjacent to each other in the coupled inductance 320. Consequently, assuming all else is equal, the dynamic magnetic flux density in some adjacent regions of the magnetic core 318 is related to the drive sequence of Fig. 17B larger than with the control sequence of Fig. 17A, which leads to higher losses in the magnetic core 318 with the control sequence of Fig. 17B than with the control sequence of Fig. 17A leads.

[0041] Peak size sections t p occur in the example of Fig. 17A at the beginning of switching cycles. However, peak magnitude sections t p alternatively occur at the end of switching cycles. For example, Fig. 18A six graphs 1802, 1804, 1806, 1808, 1810 and 1812 analogous to the graphs 1702, 1704, 1706, 1708, 1710 and 1712 of Fig. 17A of an embodiment of a multi-phase switching power converter 300, which is implemented in the same manner as in the example of Fig. 17A, but V o =8 volts instead of four volts. Each phase 302 operates in the example of Fig. 18A with a relatively large duty cycle, since the size of V o two-thirds of the magnitude of the voltage V in Consequently, in contrast to the example of Fig. 17A Peak size sections t p at the ends of the periods T instead of at the beginning of the periods T. However, the order of driving the phases 302 of the example of Fig. 18A (which is the same as in the example of Fig. 17A) still shows that successive peak magnitude intervals t p of voltage waveforms V wnot be applied to windings 310 that are immediately physically adjacent in the coupled inductance 320, thereby promoting low loss in the magnetic core 318.

[0042] For comparison, consider Fig. 18B, which includes graphs 1814, 1816, 1818, 1820, 1822, and 1824, which are analogous to graphs 1802, 1804, 1806, 1808, 1810, and 1812, respectively, but assuming that phases 302 are controlled in the following repeating sequence: phase 302(1), phase 302(2), phase 302(3), phase 302(4), phase 302(5), and phase 302(6). As can be seen from Fig. As can be seen in Figure 18B, successive peak magnitude sections t p the voltage waveforms V w applied to windings 310 that are physically adjacent to each other in the coupled inductance 320. Consequently, assuming all else is equal, the dynamic magnetic flux density in the magnetic core 318 is Fig. 18B larger than with the control sequence of Fig. 18A, which leads to higher losses in the magnetic core 318 with the control sequence of Fig. 18B than with the control sequence of Fig. 18A leads.

[0043] It should be recognized that the new multiphase switching power converters and associated methods are not limited to the phase control sequence of Fig. 17A and Fig. 18A, and accordingly, other driving sequences can be implemented so that successive peak magnitude sections t p of voltage waveforms V w not be applied to windings 310 that are physically adjacent to each other in the coupled inductance 320. The following are described with reference to Fig. 19-28 discuss some additional examples of how the novel multiphase switching power converters disclosed herein can be designed to operate such that at least some consecutive peak magnitude portions of voltage waveforms V w not be applied to windings 310 that are immediately physically adjacent to each other. However, it should be understood that the novel multiphase switching power converters disclosed herein may be configured to operate in other ways while still controlling phases 302 to maintain at least some consecutive peak magnitude portions of voltage waveforms V w not be applied to windings 310 that are immediately physically adjacent to each other.

[0044] Fig. 19 is a flowchart of a method 1900 for reducing magnetic core losses in a multiphase switching power converter including a coupled inductor, which is an example of how the novel multiphase switching power converters disclosed herein can control the phases 302. In the method 1900, it is assumed that (a) the multiphase switching power converter is the multiphase switching power converter 300 of Fig. 3, (b) N is equal to six and (c) the coupled inductance 320 is replaced by the coupled inductance 500 of Fig. 5. The control sequence of the method 1900 is as in Fig. 17A and Fig. 18A. In particular, during each iteration of the method 1900, odd phases 302 are energized one phase at a time, and after all odd phases 302 have been energized, even phases 302 are energized one phase at a time. In particular, in a block 1902 of the method 1900, phase 302(1) is energized, and in a block 1904 of the method 1900, which executes after block 1902, phase 302(3) is energized. In a block 1906 of the method 1900, which executes after block 1904, phase 302(5) is energized, and in a block 1908 of the method 1900, which executes after block 1906, phase 302(2) is energized. In a block 1910 of the method 1900, which is executed after block 1908, the phase 302(4) is controlled, and in a block 1912 of the method 1900, which is executed after block 1910, the phase 302(6) is controlled.The method 1900 returns to block 1902 after executing block 1912. The method 1900 could be modified for embodiments of the multi-phase switching power converter 300 in which N is greater than six. Furthermore, the method 1900 could be modified to drive even phases 302 before odd phases 302.

[0045] It will be appreciated that performing the method 1900 causes windings 506 that are immediately physically adjacent to each other in the coupled inductor 500 to not be sequentially driven, thereby distributing the flow of the changing magnetic flux in the magnetic core 504, which helps to minimize the magnitude of the changing magnetic flux density in the magnetic core 504. For example, Fig. 20 is a cross-sectional view of the coupled inductor 500 taken along line 8A-8A of Fig. 6, which is labeled with (a) the respective phase 302 corresponding to each winding 506 and (b) the order of driving the phases 302 according to the method 1900. In particular, the number 1 within a circle indicates that the phase 302(1), which includes the winding 506(1), is driven first, the number 2 within a circle indicates that the phase 302(3), which includes the winding 506(3), is driven second, etc. As can be seen from Fig. 20, phases 302 with immediately physically adjacent windings 506 are not energized sequentially. For example, winding 506(2) is the winding 506 closest to winding 506(1). However, phase 302(2), which includes winding 506(2), is not energized immediately after phase 302(1). Instead, phase 302(3), which includes winding 506(3), is energized immediately after phase 302(1). Winding 506(3) is farther from winding 506(1) than winding 506(2). Therefore, driving phase 302(3) instead of phase 302(2) immediately after phase 302(1) reduces the potential for a high varying magnetic flux density in the magnetic core 504 due to a large magnitude current flowing simultaneously through two windings 506 that are close to each other in the coupled inductor 500.

[0046] It should be noted that current will flow through a winding 506 for a period of time after the corresponding phase 302 of winding 506 has been energized, and in some cases, current may flow continuously through windings 506, such as when multiphase switching power converter 300 is operating in continuous conduction mode. However, sequentially energizing phases 302 with windings 506 that are relatively far apart causes immediately physically adjacent windings to carry respective peak currents at substantially different times, helping to minimize the changing magnetic flux intensity and corresponding core losses in magnetic core 504.

[0047] Fig. 21 is a flowchart of a method 2100 for reducing magnetic core losses in a multiphase switching power converter including a coupled inductor, which is another example of how the novel multiphase switching power converters disclosed herein can control the phases 302. In the method 2100, it is assumed that (a) the multiphase switching power converter is the multiphase switching power converter 300 of Fig. 3, (b) N is equal to six and (c) the coupled inductance 320 is replaced by the coupled inductance 500 of Fig. 5. The method 2100 does not follow an odd-then-even pattern like that of the method 1900, and the method 2100 generally achieves greater separation of the windings 506 of consecutively driven phases 302 than the method 1900. However, the method 2100 results in an instance of the phases 302 having immediately physically adjacent windings 506, i.e., phases 302(4) and 302(3), being driven sequentially.

[0048] In particular, in a block 2102 of the method 2100, phase 302(1) is accessed, and in a block 2104 of the method 2100, which executes after block 2102, phase 302(4) is accessed. In a block 2106 of the method 2100, which executes after block 2104, phase 302(3) is accessed, and in a block 2108 of the method 2100, which executes after block 2106, phase 302(6) is accessed. In a block 2110 of the method 2100, which executes after block 2108, phase 302(2) is accessed, and in a block 2112 of the method 2100, which executes after block 2110, phase 302(5) is accessed. The method 2100 returns to block 2102 after executing block 2112.

[0049] Fig. 22 is a cross-sectional view of the coupled inductor 500 taken along line 8A-8A of Fig. 6, which is labeled with (a) the respective phase 302 corresponding to each winding 506 and (b) the order of driving the phases 302 according to the method 2100. In particular, the number 1 in a circle indicates that the phase 302(1), which includes the winding 506(1), is driven first, the number 2 in a circle indicates that the phase 302(4), which includes the winding 506(4), is driven second, etc. As can be seen from Fig. 22, phases 302 with immediately physically adjacent windings 506 are generally not driven sequentially. For example, winding 506(2) is the winding 506 closest to winding 506(1), and winding 506(3) is the second closest winding 506 to winding 506(1). However, neither phase 302(2) nor phase 302(3) is driven immediately after phase 302(1). Instead, phase 302(4), which includes winding 506(4), is driven immediately after phase 302(1). Winding 506(4) is farther from winding 506(1) than either winding 506(2) or 506(3). Therefore, driving phase 302(4) instead of phase 302(2) or 302(3) immediately after phase 302(1) reduces the potential for a high varying magnetic flux density in the magnetic core 504 due to a large magnitude current flowing simultaneously through two windings 506 that are located close to each other.

[0050] Fig. 23 is a flowchart of a method 2300 for reducing magnetic core losses in a multiphase switching power converter including a coupled inductor, which is another example of how the novel multiphase switching power converters disclosed herein can control the phases 302. In the method 2300, it is assumed that (a) the multiphase switching power converter is the multiphase switching power converter 300 of Fig. 3, (b) N is equal to six and (c) the coupled inductance 320 is replaced by the coupled inductance 500 of Fig. 5. The method 2300 groups windings into two groups, i.e., a first group including phases 302(1), 302(2), and 302(3), and a second group including 302(4), 302(5), and 302(6). The method 2300 alternately drives a phase from each group until all phases have been driven within a given iteration of the method 2300. In particular, in a block 2302 of the method 2300, phase 302(1) is driven, and in a block 2304 of the method 2300, which executes after block 2302, phase 302(4) is driven. In a block 2306 of the method 2300, which is executed after block 2304, the phase 302(2) is controlled, and in a block 2308 of the method 2300, which is executed after block 2306, the phase 302(5) is controlled.In a block 2310 of the method 2300, which is executed after block 2308, the phase 302(3) is accessed, and in a block 2312 of the method 2300, which is executed after block 2310, the phase 302(6) is accessed. The method 2300 returns to block 2302 after executing block 2312.

[0051] Fig. 24 is a cross-sectional view of the coupled inductor 500 taken along line 8A-8A of Fig. 6, which is labeled with (a) the respective phase 302 corresponding to each winding 506 and (b) the order of driving the phases 302 according to the method 2300. In particular, the number 1 in a circle indicates that the phase 302(1), which includes the winding 506(1), is driven first, the number 2 in a circle indicates that the phase 302(4), which includes the winding 506(4), is driven second, etc. As can be seen from Fig. 24, phases 302 having immediately physically adjacent windings 506 are not sequentially driven, and in some cases, there are two intermediate windings 506 between sequentially driven windings 506. Accordingly, method 2300 reduces the potential for high magnetic flux density in magnetic core 504 resulting from a large current flowing simultaneously through two closely spaced windings 506.

[0052] Fig. 25 is a flowchart of a method 2500 for reducing magnetic core losses in a multiphase switching power converter including a coupled inductor, which is another example of how the novel multiphase switching power converters disclosed herein can control the phases 302. In the method 2500, it is assumed that (a) the multiphase switching power converter is the multiphase switching power converter 900 of Fig. 9, (b) N is six and (c) the coupled inductance 920 is replaced by the coupled inductance 1000 of Fig. 10. The method 2500 alternately drives a phase 302 from each row of windings 1008 until all phases have been driven. Specifically, in a block 2502 of the method 2500, phase 302(1) is driven, and in a block 2504 of the method 2500, which executes after block 2502, phase 302(5) is driven. In a block 2506 of the method 2500, which executes after block 2504, phase 302(3) is driven, and in a block 2508 of the method 2500, which executes after block 2506, phase 302(4) is driven. In a block 2510 of the method 2500, which is executed after block 2508, the phase 302(6) is accessed, and in a block 2512 of the method 2500, which is executed after block 2510, the phase 302(2) is accessed. The method 2500 returns to block 2502 after executing block 2512.

[0053] Fig. 26 is a cross-sectional view of the coupled inductor 1000, which is analogous to the cross-sectional view of Fig. 13 and is labeled with (a) the respective phase 302 corresponding to each winding 1008, and (b) the order of driving the phases 302 according to method 2500. In particular, the number 1 in a circle indicates that phase 302(1), which includes winding 1008(1), is driven first, the number 2 in a circle indicates that phase 302(5), which includes winding 1008(5), is driven second, etc. As can be seen from Fig. 26, phases 302 having immediately physically adjacent windings 1008 are not sequentially driven, and in some cases, there are multiple intermediate windings 1008 between sequentially driven windings 1008. Accordingly, the method 2500 reduces the potential for a high varying magnetic flux density in the magnetic core 1006 resulting from a large magnitude current flowing simultaneously through two closely spaced windings 1008.

[0054] Fig. 27 is a flowchart of a method 2700 for reducing magnetic core losses in a multi-phase switching power converter including a coupled inductor, which is an additional example of how the novel multi-phase switching power converters disclosed herein may control the phases 302. In a block 2702, the switching of multiple phases of the multi-phase switching power converter is controlled to regulate one or more parameters of the multi-phase switching power converter. In one example of block 2702, the controller 304 drives phases 302 of the multi-phase switching power converter 300 or 900 in a manner that controls the duty cycle of the phases 302 to increase the magnitude of the input voltage V in and / or the magnitude of the input current I in and / or the magnitude of the output voltage V o and / or to regulate the magnitude of the output current 1".

[0055] In a block 2704 of the method 2700, which is executed after block 2702, the flow of the changing magnetic flux in a magnetic core of the coupled inductor is distributed by driving the multiple phases of the multi-phase switching power converter such that at least some phases with respective windings that are immediately physically adjacent to each other in the coupled inductor are not driven one after the other. In one example of block 2704, the controller 304 distributes the flow of the magnetic flux in the magnetic core 318 or 318 by driving phases 302 according to the Fig. 17A, Fig. 18A and Fig. 19 or according to one of the methods 2100, 2300 or 2500.

[0056] Fig. 28 is a flowchart of a method 2800 for reducing magnetic core losses in a multi-phase switching power converter including a coupled inductor, which is an additional example of how the novel multi-phase switching power converters disclosed herein may control the phases 302. In a block 2802 of the method 2800, a plurality of periodic voltage waveforms are generated, with each periodic voltage waveform being applied to a respective one of a plurality of windings of the coupled inductor. In one example of block 2802, the controller 304 controls switching stages 308 to generate the periodic voltage waveforms V w from Fig. 17A, which are applied to respective windings 310 of the coupled inductor 320. In another example of block 2802, the controller 304 controls switching stages 308 to generate the periodic voltage waveforms V w from Fig. 18A, which are applied to respective windings 310 of the coupled inductance 320.

[0057] At a block 2804 of the method 2800, the flow of the changing magnetic flux in a magnetic core of the coupled inductor is distributed by controlling a phase shift between the plurality of periodic voltage waveforms such that at least two consecutive peak magnitude portions of the plurality of periodic voltage waveforms are not applied to respective windings of the plurality of windings of the coupled inductor that are immediately physically adjacent to each other. In one example of block 2804, the controller 304 controls switching stages 308 to be in the Fig. 17A or Fig. 18A, resulting in a phase shift between periodic voltage waveforms V w so that successive peak magnitude sections t pnot be applied to immediately physically adjacent windings 310 in the coupled inductor 320. In another example of block 2808, the controller 304 controls switching stages 308 to be driven in sequence according to one of methods 2100, 2300, or 2500, which also results in a phase shift between periodic voltage waveforms V w so that successive peak magnitude sections of voltage waveforms V w not be applied to immediately physically adjacent windings 310 in the coupled inductor 320 or 920.

[0058] With further reference to Fig. 3 and Fig. 9, a desired sequence of controlling the phases 302 is achieved, for example, by configuring the controller 304 to implement a desired sequence of controlling the phases 302 and / or by assigning control signals generated by the controller 304 to the phases 302 such that a desired sequence of controlling the phases 302 is achieved. The control signals generated by the controller 304 are assigned to the phases 302, for example, by selectively connecting output terminals, e.g., electrical terminals, of the controller 304 to switching stages 308.

[0059] For example, Fig. 29 is a block diagram of a controller 2900, which is one possible embodiment of the controller 304 that can be configured to achieve a desired order of driving the phases 302. The controller 2900 includes an interface module 2902, a control module 2904, a protection module 2906, and a drive order module 2908. The aforementioned modules 2902-2908 of the controller 2900 are implemented, for example, by analog electronic circuitry and / or by digital electronic circuitry. Furthermore, in some embodiments, at least a portion of one or more of the modules 2902-2908 are implemented by a processor executing instructions, such as software and / or firmware, stored in a memory device.

[0060] The interface module 2902 is configured to couple the controller 2900 to one or more devices external to the controller 2902. For example, Fig. 29 illustrates the interface module 2902, which provides an interface for control signals U and L to devices external to the controller 2900, such as switching circuits 308. The interface module 2902 may also provide an interface for one or more additional signals, such as feedback signals, telemetry signals, additional control signals, etc. In some embodiments, the interface module 2902 includes level translation circuitry, isolation circuitry, signal processing circuitry, digital-to-analog conversion circuitry, and / or analog-to-digital conversion circuitry.

[0061] The control module 2904 is configured to control the generation of control signals U and L to control one or more parameters of the multiphase switching power converter 300 or 900, such as the magnitude of the voltage V in, of current I in , the voltage V o and / or the current I o . Some embodiments of the controller 2900 are configured to implement the above-mentioned control using a PWM technique or a PFM technique.

[0062] The protection module 2906 is configured to cooperate with the control module 2904 and / or the interface module 2902 to implement one or more protection functions of the multi-phase switching power converter 300 or 900, such as short-circuit protection, overcurrent protection, overvoltage protection, soft-start functionality, current sharing functionality, etc. The drive sequence module 2908 is configured to cooperate with the control module 2904 and / or the interface module 2902 to drive phases 302 according to instructions 2910. For example, the instructions 2910 include instructions for driving phases 302 according to one of method 1900, method 2100, method 2300, or method 2500. In some embodiments, the instructions 2910 include data stored in a memory or other data storage device.In some other embodiments, instructions 2910 include a physical arrangement of elements of controller 2900, such as a switch configuration, a bypass configuration, a fuse pattern, etc.

[0063] Fig. 30 is a block diagram illustrating an example of how a desired order of driving the phases 302 may be achieved by selectively assigning control signals generated by the controller 304 to the phases 302 in an embodiment of the multi-phase switching power converter 300 or 900 in which N is equal to six. Fig. 30 includes a controller 3000, six instances of phases 302 and six logical connections 3002. Details of phases 302 are described in Fig. 30 not shown for clarity of illustration. The controller 3000 is configured to generate respective control signals for each phase 302, such as control signals U and L, at each of six output terminals A, B, C, D, E, and F. In other words, each output terminal A, B, C, D, E, and F provides control signals for a respective phase 302. The controller 3000 is further configured to generate control signals to drive the phases 302 according to the following order: (1) drive the phase 302 connected to output port A, (2) drive the phase 302 connected to output port B, (3) drive the phase 302 connected to output port C, (4) drive the phase 302 connected to output port D, (5) drive the phase 302 connected to output port E, and (6) drive the phase 302 connected to output port F.Although the order of generation of control signals by the controller 3000 is not adjustable, a desired drive order of the phases 302 can still be achieved by selectively communicatively coupling the output terminals AF to the phases 302 via the logic connections 3002. For example, the illustrated configuration of the logic connections 3002 in . Fig. 30 illustrates the drive sequence of method 1900 by communicatively coupling output port A to phase 302(1), output port B to phase 302(3), etc. Each logical connection 3002 may, but need not, be a physical connection. Accordingly, in certain embodiments, two or more logical connections 3002 are implemented by a single physical connection, such as a single bus carrying multiple control signals.

[0064] With further reference to Fig. 3 and Fig. 9, while the multi-phase switching power converters 300 and 900 have a buck conversion topology, the novel multi-phase switching power converters disclosed herein are not limited to having a buck conversion topology. Instead, the novel multi-phase switching power converters may have substantially any topology, including, but not limited to, a boost conversion topology or a buck-boost conversion topology compatible with a coupled inductor and capable of applying a respective voltage waveform, e.g., a square wave voltage waveform, to each winding of the coupled inductor. Such topologies may also be modified to be multi-level and / or isolated topologies compatible with a coupled inductor. For example, Fig. 31 is a circuit diagram of a multiphase switching power converter 3100, which is an alternative embodiment of the multiphase switching power converter 300 modified to have a boost conversion topology. Each switching stage 308 is configured to switch its respective switching node X between the reference node 314 and the output power node 312 in response to the control signals U and L to generate a respective voltage waveform V w at its respective winding 310. Accordingly, a given phase 302 of the multiphase switching power converter 3100 is controlled by its respective switching stage 308 connecting its respective switching node X to the reference node 314, e.g., by the switching stage 308 changing its operating state such that the switching node X is connected to the reference node 314 instead of being connected to the output power node 312.

[0065] Another example is Fig. 32 is a circuit diagram of a multiphase switching power converter 3200, which is an alternative embodiment of the multiphase switching power converter 300 modified to have a buck-boost topology. Each switching stage 308 is configured to switch its respective switching node X between the input power node 316 and the output power node 312 in response to the control signals U and L to generate a respective voltage waveform V w at its respective winding 310. Accordingly, a given phase 302 of the multiphase switching power converter 3200 is controlled by its respective switching stage 308 connecting its respective switching node X to the input power node 316, e.g., by the switching stage 308 changing its operating state such that the switching node X is connected to the input power node 316 instead of being connected to the output power node 312.

[0066] The multiphase switching power converters disclosed herein could be configured to receive power from multiple input power nodes and / or deliver output power to multiple output power nodes without departing from the scope of the present invention. For example, Fig. 33 is a circuit diagram of a multi-phase switching power converter 3300, which is an alternative embodiment of switching power converter 300, configured to (a) receive power from three input power nodes 316(1), 316(2), and 316(3) and (b) supply power to three output power nodes 312(1), 312(2), and 312(3). In particular, phase 302(1) is configured to receive power from input power node 316(1) and supply power to output power node 312(1), and phase 302(2) is configured to receive power from input power node 316(2) and supply power to output power node 312(2). In addition, phases 302(3)-302(N) are configured to receive power from input power node 316(3) and supply power to output power node 312(3).In some embodiments, two or more of input power nodes 316(1), 316(2), and 316(3) are at a different electrical potential with respect to reference node 314. Furthermore, in certain embodiments, two or more of output power nodes 312(1), output power node 312(2), and output power node 312(3) are at a different electrical potential with respect to reference node 314. The number of input power nodes 316, the number of output power nodes 312, and the specific phases 302 associated with each input power node 316 and each output power node 312 could be different without departing from the scope of the present invention.

[0067] The multiphase switching power converters disclosed herein could also be designed as multilevel switching power converters, i.e., switching power converters with three or more levels. For example, the switching stages 308 of the multiphase switching power converter 300 could be configured as shown in Fig. 34 so that the multi-phase switching power converter 300 is a three-level switching power converter instead of a two-level switching power converter. Fig. 34 is a circuit diagram of N switching stages 3402, wherein the switching stages 3402 are another embodiment of the switching stages 308 of Fig. 3. Each switching stage 3402 includes a first upper switching device 3404, a second upper switching device 3406, a first lower switching device 3408, a second lower switching device 3410, and a flying capacitor 3412. Each first upper switching device 3404 and each second upper switching device 3406 is electrically connected in series between the input power node 316 and the switching node X of its respective phase 302. Each first lower switching device 3408 and each second lower switching device 3410 is electrically connected in series between the switching node X of its respective phase 302 and the reference node 314.Within each switching stage 3402, a flying capacitor 3412 is electrically coupled between (a) a first capacitor node 3414 connecting the first upper switching device 3404 and the second upper switching device 3406, and (b) a second capacitor node 3416 connecting the first lower switching device 3408 and the second lower switching device 3410.

[0068] In embodiments in which the switching stages 308 according to Fig. 34 are implemented, the controller 304 is modified to generate the following four control signals for each switching stage 3402: (a) a control signal U a , (b) a control signal U b , (c) a control signal L a and (d) a control signal L b . Each first upper switching device 3404 switches in response to a respective control signal U afrom the controller 304, and each second upper switching device 3406 switches in response to a respective control signal U b , which is generated by the controller 304. Each first lower switching device 3408 switches in response to a respective control signal L a from the controller 304, and each second lower switching device 3410 switches in response to a respective control signal L b from the controller 304. Each switching device 3404, 3406, 3408, and 3410 includes, for example, one or more transistors.

[0069] In certain embodiments, the controller 304 is configured to (a) provide control signals U a and U b for a given switching stage 3402, so that the first upper switching device 3404 and the second upper switching device 3406 of the switching stage switch out of phase with each other, (b) control signals U a and U bto generate to control the duty cycle of the first upper switching devices 3404 and the second upper switching devices 3406 to regulate one or more parameters of the multi-phase switching power converter 300, such as using a PWM or PFM technique, and (c) for each switching stage 3402, control signals L a and L b such that the second lower switching device 3410 performs a freewheeling function for the first upper switching device 3404, and such that the first lower switching device 3408 performs a freewheeling function for the second upper switching device 3406. The switching stages 3402 could be modified to support additional switching power conversion levels, such as by adding one or more additional sets of an upper switching device, a lower switching device, and a flying capacitor. Combinations of features

[0070] The features described above can be combined in various ways without deviating from the scope of protection. The following examples illustrate some possible combinations.

[0071] (A1) A method for reducing magnetic core losses in a multi-phase switching power converter including a coupled inductor includes (1) generating a plurality of periodic voltage waveforms, each periodic voltage waveform being applied to a respective one of a plurality of windings of the coupled inductor, and (2) distributing a flow of changing magnetic flux in a magnetic core of the coupled inductor by controlling a phase shift between the plurality of periodic voltage waveforms such that at least two consecutive peak magnitude portions of the plurality of periodic voltage waveforms are not applied to respective ones of the plurality of windings of the coupled inductor that are immediately physically adjacent to each other.

[0072] (A2) In the method denoted as (A1), each periodic voltage waveform may be a respective rectangular voltage waveform.

[0073] (A3) In one of the methods referred to as (A1) and (A2), (1) a first phase of the plurality of phases of the multi-phase switching power converter may include a first winding of the plurality of windings of the coupled inductor, (2) a second phase of the plurality of phases of the multi-phase switching power converter may include a second winding of the plurality of windings of the coupled inductor, (3) an additional phase of the plurality of phases of the multi-phase switching power converter may include an additional winding of the plurality of windings of the coupled inductor, (4) the first winding may be farther from the additional winding than from the second winding, and (5) such controlling may include a phase shift between the plurality of periodic voltage waveforms,that at least two consecutive peak magnitude portions of the plurality of periodic voltage waveforms are not applied to respective windings of the plurality of windings of the coupled inductor that are immediately physically adjacent to each other, (i) driving the first phase and (ii) after driving the first phase but before driving the second phase, driving the additional phase.

[0074] (A4) In the method referred to as (A3), the second winding may be located between the first winding and the additional winding in the coupled inductance.

[0075] (A5) In one of the methods referred to as (A3) or (A4), the first winding, the second winding and the additional winding may be located within a common row of the coupled inductance.

[0076] (A6) In either of the methods referred to as (A3) or (A4), at least two of the first winding, the second winding and the additional winding may be located within different respective rows of the coupled inductance.

[0077] (A7) In any of the methods referred to as (A3) to (A6), a magnetic core of the coupled inductor may include a plurality of winding posts, and the first winding, the second winding, and the additional winding may each be at least partially wound around a respective winding post of the plurality of winding posts.

[0078] (A8) In any of the methods referred to as (A3) to (A7), (1) driving the first phase may include electrically connecting a switching node of the first phase to a first power node, (2) driving the second phase may include electrically connecting a switching node of the second phase to the first power node, and (3) driving the additional phase may include electrically connecting a switching node of the additional phase to the first power node.

[0079] (A9) In any of the methods referred to as (A3) to (A7), (1) driving the first phase may include electrically connecting a first phase switching node to a first power node, (2) driving the second phase may include electrically connecting a second phase switching node to a second power node, and (3) driving the additional phase may include electrically connecting a additional phase switching node to an additional power node.

[0080] (A10) In the method referred to as (A9), at least two of the first power node, the second power node and the additional power node may be at different respective electrical potentials with respect to a reference node.

[0081] (A11) In any of the methods referred to as (A3) to (A7), (1) driving the first phase may include switching a first phase switching node from a reference node to a first power node, (2) driving the second phase may include switching a second phase switching node from the reference node to the first power node, and (3) driving the additional phase may include switching a additional phase switching node from the reference node to the first power node.

[0082] (A12) In any of the methods referred to as (A3) to (A7), (1) driving the first phase may include switching a first phase switching node from a reference node to a first power node, (2) driving the second phase may include switching a second phase switching node from the reference node to a second power node, and (3) driving the additional phase may include switching a additional phase switching node from the reference node to an additional power node.

[0083] (A13) In the method referred to as (A12), at least two of the first power node, the second power node, and the additional power node may be at different respective electrical potentials with respect to the reference node.

[0084] (A14) In any of the methods referred to as (A3) to (A13), the first winding may be farther from the additional winding than from a third winding of the plurality of windings of the coupled inductor, and the third winding may be part of a third phase of the plurality of phases of the multi-phase switching power converter.

[0085] (A15) In any of the methods referred to as (A3) to (A14), at least two windings of the plurality of windings of the coupled inductor may share one or more magnetic leakage flux transfer elements of the magnetic core of the coupled inductor.

[0086] (A16) Any of the methods referred to as (A1) to (A15) may further include controlling the switching of the multiple phases of the multiphase switching power converter to regulate one or more parameters of the multiphase switching power converter.

[0087] (A17) In the method referred to as (A16), the one or more parameters of the multi-phase switching power converter may include (a) a magnitude of a voltage of the multi-phase switching power converter and / or (b) a magnitude of a current of the multi-phase switching power converter.

[0088] (A18) In any of the methods referred to as (A1) to (A17), the multi-phase switching power converter may be selected from the group consisting of a multi-phase buck switching power converter, a multi-phase boost switching power converter, and a multi-phase buck-boost switching power converter.

[0089] (B1) A multi-phase switching power converter includes (1) a coupled inductor including a plurality of windings and a magnetic core, each winding of the plurality of windings being part of a respective phase of a plurality of phases of the multi-phase switching power converter, (2) a plurality of switching stages, each switching stage of the plurality of switching stages being part of a respective phase of the plurality of phases of the multi-phase switching power converter, and (3) a controller configured to (i) control the plurality of switching stages to generate a plurality of periodic voltage waveforms, each periodic voltage waveform being applied to a respective winding of the plurality of windings of the coupled inductor, and (ii) cause a changing magnetic flux to be distributed within the magnetic core of the coupled inductor by controlling a phase shift between the plurality of periodic voltage waveforms sothat at least two consecutive peak magnitude portions of the plurality of periodic voltage waveforms are not applied to respective windings of the plurality of windings of the coupled inductor that are immediately physically adjacent to each other.

[0090] (B2) In the multiphase switching power converter designated as (B1), the multiple windings of the coupled inductor may be located within a common row of the coupled inductor.

[0091] (B3) In the multi-phase switching power converter designated as (B1), at least two windings of the plurality of windings of the coupled inductor may be located within different respective rows of the coupled inductor.

[0092] (B4) In any of the multi-phase switching power converters designated as (B1) to (B3), at least two windings of the plurality of windings of the coupled inductor may share one or more magnetic leakage flux transfer elements of the magnetic core of the coupled inductor.

[0093] (C1) A method for reducing magnetic core losses in a multi-phase switching power converter including a coupled inductor includes (1) controlling the switching of a plurality of phases of the multi-phase switching power converter to regulate one or more parameters of the multi-phase switching power converter, and (2) distributing a flow of changing magnetic flux in a magnetic core of the coupled inductor by driving the plurality of phases of the multi-phase switching power converter such that at least some phases having respective windings that are immediately physically adjacent to each other in the coupled inductor are not driven sequentially.

[0094] (C2) In the method referred to as (C1), the multi-phase switching power converter may be selected from the group consisting of a multi-phase buck switching power converter, a multi-phase boost switching power converter, and a multi-phase buck-boost switching power converter.

[0095] (C3) In one of the methods referred to as (C1) or (C2), the one or more parameters of the multi-phase switching power converter may include (a) a magnitude of a voltage of the multi-phase switching power converter and / or (b) a magnitude of a current of the multi-phase switching power converter.

[0096] Changes may be made to the above methods, apparatus, and systems without departing from the scope of the present invention. Therefore, it is to be understood that the subject matter contained in the foregoing description and shown in the accompanying drawings is to be considered as illustrative and not restrictive. The following claims are intended to cover generic and specific features described herein, as well as all statements concerning the scope of the present method and system that may be interpreted as falling therebetween.

[0097] Aspects of the present disclosure relate to a method for reducing magnetic core losses in a multi-phase switching power converter including a coupled inductor. The method includes (a) generating a plurality of periodic voltage waveforms, each periodic voltage waveform being applied to a respective one of a plurality of windings of the coupled inductor, and (b) distributing a flux of changing magnetic flux in a magnetic core of the coupled inductor by controlling a phase shift between the plurality of periodic voltage waveforms such that at least two consecutive peak magnitude portions of the plurality of periodic voltage waveforms are not applied to respective ones of the plurality of windings of the coupled inductor that are immediately physically adjacent to one another. QUOTES CONTAINED IN THE DESCRIPTION

[0000] This list of documents submitted by the applicant was generated automatically and is included solely for the convenience of the reader. This list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions. Cited patent literature

[0000] US 63 / 609,226

[0001] US 18 / 966,358

[0001]

Claims

[1] A method for reducing magnetic core losses in a multi-phase switching power converter including a coupled inductor, the method comprising: generating a plurality of periodic voltage waveforms, each periodic voltage waveform being applied to a respective one of a plurality of windings of the coupled inductor; and Distributing a flow of a changing magnetic flux in a magnetic core of the coupled inductor by controlling a phase shift between the plurality of periodic voltage waveforms such that at least two consecutive peak magnitude portions of the plurality of periodic voltage waveforms are not applied to respective windings of the plurality of windings of the coupled inductor that are immediately physically adjacent to one another. [2] The method of claim 1, wherein each periodic voltage waveform is a respective square voltage waveform. [3] A method according to claim 1 or 2, wherein: a first phase of the plurality of phases of the multi-phase switching power converter includes a first winding of the plurality of windings of the coupled inductor; a second phase of the plurality of phases of the multi-phase switching power converter includes a second winding of the plurality of windings of the coupled inductor; an additional phase of the plurality of phases of the multi-phase switching power converter includes an additional winding of the plurality of windings of the coupled inductor; the first winding is further away from the additional winding than from the second winding; and controlling a phase shift between the plurality of periodic voltage waveforms such that at least two consecutive peak magnitude portions of the plurality of periodic voltage waveforms are not applied to respective windings of the plurality of windings of the coupled inductor that are immediately physically adjacent to each other, comprising: Controlling the first phase; and after controlling the first phase, but before controlling the second phase, controlling the additional phase. [4] The method of claim 3, wherein the second winding is located between the first winding and the additional winding in the coupled inductor. [5] A method according to claim 3 or 4, wherein the first winding, the second winding and the additional winding are located within a common row of the coupled inductance. [6] The method of claim 3 or 4, wherein at least two of the first winding, the second winding and the additional winding are located within different respective rows of the coupled inductor. [7] A method according to any one of claims 3 to 6, wherein: a magnetic core of the coupled inductance comprises a plurality of winding posts; and the first winding, the second winding and the additional winding are each at least partially wound around a respective winding post of the plurality of winding posts. [8] A method according to any one of claims 3 to 7, wherein: driving the first phase comprises electrically connecting a switching node of the first phase to a first power node; driving the second phase comprises electrically connecting a switching node of the second phase to the first power node; and controlling the additional phase comprises electrically connecting a switching node of the additional phase to the first power node. [9] A method according to any one of claims 3 to 7, wherein: driving the first phase comprises electrically connecting a switching node of the first phase to a first power node; driving the second phase comprises electrically connecting a switching node of the second phase to a second power node; and controlling the additional phase comprises electrically connecting a switching node of the additional phase to an additional power node. [10] The method of claim 9, wherein at least two of the first power node, the second power node, and the additional power node are at different respective electrical potentials with respect to a reference node. [11] A method according to any one of claims 3 to 7, wherein: controlling the first phase comprises switching a switching node of the first phase from a reference node to a first power node; controlling the second phase comprises switching a second phase switching node from the reference node to the first power node; and driving the additional phase comprises switching a switching node of the additional phase from the reference node to the first power node. [12] A method according to any one of claims 3 to 7, wherein: controlling the first phase comprises switching a switching node of the first phase from a reference node to a first power node; controlling the second phase comprises switching a second phase switching node from the reference node to a second power node; and controlling the additional phase comprises switching a switching node of the additional phase from the reference node to an additional power node. [13] The method of claim 12, wherein at least two of the first power node, the second power node, and the additional power node are at different respective electrical potentials with respect to the reference node. [14] The method of any one of claims 3 to 13, wherein the first winding is further away from the additional winding than from a third winding of the plurality of windings of the coupled inductor, the third winding being part of a third phase of the plurality of phases of the multi-phase switching power converter. [15] The method of any one of claims 1 to 14, wherein at least two windings of the plurality of windings of the coupled inductor share one or more magnetic leakage flux transfer elements of the magnetic core of the coupled inductor. [16] The method of any one of claims 1 to 15, further comprising controlling the switching of the multiple phases of the multiphase switching power converter to regulate one or more parameters of the multiphase switching power converter. [17] Multiphase switching power converter comprising: a coupled inductor including a plurality of windings and a magnetic core, each winding of the plurality of windings being part of a respective one of a plurality of phases of the multi-phase switching power converter; a plurality of switching stages, each switching stage of the plurality of switching stages being part of a respective one of the plurality of phases of the multi-phase switching power converter; and a control system designed to: Controlling the plurality of switching stages to generate a plurality of periodic voltage waveforms, each periodic voltage waveform being applied to a respective one of the plurality of windings of the coupled inductor, and Causing a changing magnetic flux to be distributed within the magnetic core of the coupled inductor by controlling a phase shift between the plurality of periodic voltage waveforms such that at least two consecutive peak magnitude portions of the plurality of periodic voltage waveforms are not applied to respective windings of the plurality of windings of the coupled inductor that are immediately physically adjacent to one another. [18] The multi-phase switching power converter of claim 17, wherein at least two windings of the plurality of windings of the coupled inductor share one or more magnetic leakage flux transfer elements of the magnetic core of the coupled inductor. [19] A method for reducing magnetic core losses in a multi-phase switching power converter including a coupled inductor, the method comprising: Controlling the switching of multiple phases of the multiphase switching power converter to regulate one or more parameters of the multiphase switching power converter; and Distributing a flow of a changing magnetic flux in a magnetic core of the coupled inductor by driving the multiple phases of the multi-phase switching power converter such that at least some phases having respective windings that are immediately physically adjacent to each other in the coupled inductor are not driven sequentially. [20] The method of claim 19, wherein: the multiphase switching power converter is selected from the group consisting of a multiphase step-down switching power converter, a multiphase step-up switching power converter, and a multiphase step-down-step-up switching power converter; and the one or more parameters of the multi-phase switching power converter comprise (a) a magnitude of a voltage of the multi-phase switching power converter and / or (b) a magnitude of a current of the multi-phase switching power converter.

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