CN114242403B

CN114242403B - Power converter and inductance structure

Info

Publication number: CN114242403B
Application number: CN202111350499.5A
Authority: CN
Inventors: 代克; 危建; 颜佳佳
Original assignee: Nanjing Sili Microelectronics Technology Co ltd
Current assignee: Nanjing Sili Microelectronics Technology Co ltd
Priority date: 2021-11-15
Filing date: 2021-11-15
Publication date: 2024-06-18
Anticipated expiration: 2041-11-15
Also published as: CN114242403A

Abstract

The invention discloses a power converter and an inductance structure, wherein the power converter comprises an inductance structure, and the inductance structure comprises first to N-th inductance coils and a coupling coil. Each path of the inductance coil and the corresponding transistor form a power stage circuit so as to generate an output signal at the output end of the power stage circuit; the coupling coil and each path of inductance coil are in negative coupling relation. The indirect coupling mode is to realize the negative coupling among multiple paths of inductors, so that the transient response of large-current application is solved, and the current sharing among all paths is realized.

Description

Power converter and inductance structure

Technical Field

The present invention relates to semiconductor technology, and more particularly, to a power converter, and an inductance structure.

Background

The high-current multi-path parallel structure has become a main structure of a voltage regulation module (Voltage Regulator Module, VRM) circuit for supplying power to a CPU, a server and the like. And most of the used inductors are ferrite inductors which are used side by side. However, ferrite inductors cannot be designed to be smaller because of their lower saturation flux density and lower thermal conductivity. When the multi-path ferrite inductors are used side by side, when the load of one path suddenly changes, other paths sense the load slowly, and current sharing among the paths is not easy to realize.

Disclosure of Invention

In view of the above, the present invention provides a power converter and an inductor structure to solve the above-mentioned problems.

According to a first aspect of the present invention, there is provided a power converter comprising: an inductance structure including first to nth inductance coils, and a coupling coil; each path of the inductance coil and the corresponding transistor form a power stage circuit so as to generate an output signal at the output end of the power stage circuit; the coupling coil and each path of inductance coil are in negative coupling relation.

Preferably, the coupling relationship between the coupling coil and the inductance coil is stronger than the coupling relationship between any two inductance coils.

Preferably, any two paths of the inductance coils are in a negative coupling relationship, and the coupling coefficient between the coupling coils and the inductance coils is larger than that between any two paths of the inductance coils.

Preferably, the input end of each power stage circuit receives the same input voltage source, and the output end of each power stage circuit generates one output signal.

Preferably, the inductance structure includes: a first magnetic core comprising a substrate and at least two magnetic core legs positioned on the substrate; at least two first windings, each first winding being wound around one of the magnetic core limbs, any two of the at least two first windings being separated from each other to form the inductor; and a second winding wound around at least two of the magnetic core legs and located above the first winding to form the coupling coil.

According to a second aspect of the present invention, there is provided an inductance structure comprising: a first magnetic core comprising a substrate and at least two magnetic core legs positioned on the substrate; at least two first windings, each of which is wound with one magnetic core column, and a space exists between any two of the at least two first windings; and a second winding wound on the at least two magnetic core legs.

Preferably, a coupling coefficient between the second winding and any one of the at least two first windings is larger than a coupling coefficient between two adjacent first windings.

Preferably, the transformer further comprises a second magnetic core, wherein the second magnetic core is positioned on the substrate and covers the at least two first windings, the second windings and the first magnetic core.

Preferably, the number of the first windings is less than or equal to the number of the magnetic core columns.

Preferably, the second magnetic core and the first magnetic core are magnetic powder cores of the same material.

Preferably, the second magnetic core and the first magnetic core are magnetic powder cores of different materials.

Preferably, the magnetic permeability of the first magnetic core is greater than the magnetic permeability of the second magnetic core.

Preferably, when the number of the magnetic core limbs is greater than the number of the first windings, the magnetic core limbs which are not wound by the first windings are the same as the material of the second magnetic core.

Preferably, the core legs are arranged side by side.

Preferably, the magnetic core columns are arranged in a plurality of rows.

Preferably, the outgoing lines of the first winding are located on the same side of the substrate.

Preferably, the outgoing lines of the first winding are located on different sides of the substrate.

Preferably, the second winding is located above the first winding.

In summary, the invention discloses a power converter and an inductance structure, which realize negative coupling among multiple paths of inductances in an indirect coupling mode, solve the transient response of high-current application and realize current sharing among all paths. In addition, the magnetic powder core material is selected as the magnetic core, so that the heat conductivity is higher, the heat dissipation capacity of the inductor is improved, and the volume of the inductor is reduced.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings that are required to be used in the embodiments or the description of the prior art will be briefly described below, and it is obvious that the drawings in the following description are only embodiments of the present invention, and that other drawings can be obtained according to the provided drawings without inventive effort for a person skilled in the art.

FIG. 1 is a circuit diagram of a power converter according to the present invention;

fig. 2a is a schematic diagram of a first inductor structure according to the present invention;

fig. 2b is a schematic diagram of a portion of a first inductor structure according to the present invention;

fig. 3 is a schematic diagram of a second inductor structure according to the present invention;

Fig. 4 is a simulation waveform of a second inductor structure provided by the present invention;

fig. 5 is a schematic diagram of a third inductor structure according to the present invention.

Detailed Description

The present invention is described below based on examples, but the present invention is not limited to only these examples. In the following detailed description of the present invention, certain specific details are set forth in detail. The present invention will be fully understood by those skilled in the art without the details described herein. Well-known methods, procedures, flows, components and circuits have not been described in detail so as not to obscure the nature of the invention.

Moreover, those of ordinary skill in the art will appreciate that the drawings are provided herein for illustrative purposes and that the drawings are not necessarily drawn to scale.

Meanwhile, it should be understood that in the following description, "circuit" refers to a conductive loop constituted by at least one element or sub-circuit through electrical connection or electromagnetic connection. When an element or circuit is referred to as being "connected to" another element or being "connected between" two nodes, it can be directly coupled or connected to the other element or intervening elements may be present and the connection between the elements may be physical, logical, or a combination thereof. In contrast, when an element is referred to as being "directly coupled to" or "directly connected to" another element, it means that there are no intervening elements present between the two.

Unless the context clearly requires otherwise, throughout the description and the claims, the words "comprise", "comprising", and the like are to be construed in an inclusive sense as opposed to an exclusive or exhaustive sense; that is, it is the meaning of "including but not limited to".

In the description of the present invention, it should be understood that the terms "first," "second," and the like are used for descriptive purposes only and are not to be construed as indicating or implying relative importance. Furthermore, in the description of the present invention, unless otherwise indicated, the meaning of "a plurality" is two or more.

Fig. 1 is a circuit configuration diagram of a power converter according to the present invention. Specifically, as shown in fig. 1, the power converter includes an inductance structure including first to nth inductance coils L1 to Ln and a coupling coil 400. Wherein each of the inductors and the corresponding transistor form a power stage circuit to generate an output signal Vout at an output terminal of the power stage circuit, for example, the first inductor L1 and the corresponding transistors Q10 and Q11 form a first power stage circuit; the first path of inductance coil L2 and corresponding transistors Q20 and Q21 form a second path of power stage circuit; and so on, the nth inductor Ln and the corresponding transistors Qn0 and Qn1 form an nth power stage circuit. The coupling coil 400 is in negative coupling relation with each of the inductance coils L1-Ln.

The coupling relationship between the coupling coil 400 and the inductance coil is stronger than the coupling relationship between any two inductance coils. Specifically, any two paths of the inductance coils form a negative coupling relationship, and the coupling coefficient between the coupling coil and the inductance coils is larger than the coupling coefficient between any two paths of the inductance coils, that is, the coupling coefficient between the coupling coil 400 and the inductance coils of any one path is larger than the coupling coefficient between any two paths of the inductance coils.

The input end of each power stage circuit receives the same input voltage source Vin, and the output end of each power stage circuit generates an output signal Vout.

The inductance structure of this embodiment includes: a first magnetic core comprising a substrate and at least two magnetic core legs positioned on the substrate; at least two first windings, each first winding being wound around one of the magnetic core limbs, any two of the at least two first windings being separated from each other to form the inductor; and a second winding wound around at least two of the magnetic core legs and located above the first winding to form the coupling coil.

Fig. 2a is a schematic diagram of a first inductor structure provided by the present invention, and fig. 2b is a partial schematic diagram of the first inductor structure provided by the present invention, so as to more clearly show the structure of the upper surface of the first winding. Specifically, as shown in fig. 2a and 2b, the inductor 100 comprises a first magnetic core, at least two first windings (111 and 112) and a second winding 121. The first magnetic core comprises a substrate 101 and at least two magnetic core columns 102, wherein each first winding is wound on one magnetic core column, and a space is reserved between two adjacent first windings in the at least two first windings; the second winding 121 is wound around the at least two magnetic core limbs. The number of the first windings is smaller than or equal to the number of the magnetic core columns.

The inductor further comprises a second magnetic core 131, wherein the second magnetic core 131 is located on the substrate 101 and covers the first magnetic core, the first windings (111 and 112) and the second winding 121.

In this embodiment, the number of the magnetic core legs is equal to the number of the first windings, that is, one of the first windings winds one of the magnetic core legs. Specifically, the number of the magnetic core post and the first winding is 2. In other embodiments, the number of magnetic core columns and the number of first windings may be set as required, so long as the number of first windings is less than or equal to the number of magnetic core columns, which is not limited herein. Meanwhile, the number of turns of the first winding and the second winding for winding the magnetic core column can be set according to the requirement, and the winding is not limited.

The first magnetic core and the second magnetic core 131 may be magnetic powder cores of the same material, or magnetic powder cores of different materials, and in this embodiment, the magnetic permeability of the first magnetic core is preferably greater than the magnetic permeability of the second magnetic core 131. Since the magnetic powder core has very low magnetic permeability, the coupling coefficient of the second winding and any one of the at least two first windings is larger than the coupling coefficient between the first windings, and the coupling coefficient of the second winding and any one of the at least two first windings can be adjusted by their positional relationship.

The first magnetic core, the first winding and the second winding may be integrally formed, or the first magnetic core may be formed first, and then the first winding and the second winding may be reassembled with the first magnetic core, which is not limited in any way.

In this embodiment, the outgoing lines of the first winding extend to the same side of the substrate 101, and of course, in other embodiments, the outgoing lines of the first winding may extend to two opposite sides of the substrate 101.

Taking the structure of the first inductor as an example, if the self inductance of the two first windings is L1 and L2, respectively, l1=l2; the mutual inductances between the first winding and the second winding are M13 and M31, the mutual inductances between the second winding and the first winding are M23 and M32, and m13=m31=m23=m32; the mutual inductance between the two first windings is M12 and M21, m12=m21.

Setting l1=l2=l; m13=m31=m23=m32=m; m12=m21= Ms, then there is:

The voltage across the first winding

The voltage across the second first winding

Where i ₁ is the current through the first winding, i ₂ is the current through the second first winding, and i _c is the current through the second winding. The three formulas (1), (2) and (3) can arrange the two paths of indirectly coupled inductors into the relationship forms (4) and (5) of voltages at two ends of the common two paths of coupled inductors:

Assume that

Then there is

From the formulas (4) and (5), it can be explained that the two-path indirectly coupled inductor provided by the application can realize negative coupling between the two-path inductors.

Fig. 3 is a schematic diagram of a second inductor structure according to the present invention. As shown in fig. 3, the main difference between the second inductance structure and the first inductance structure is that: the second inductor structure is a four-way output inductor, namely the number of the first windings (211, 212, 213, 214) and the magnetic core columns 202 is 4. The first winding and the second winding 221 are each wound by one turn. The other structures are substantially the same and are not described in detail herein. The magnetic core columns of the present embodiment may be arranged in a row side by side, or may be arranged in two rows, and the arrangement manner thereof may be set by those skilled in the art according to the needs, which is not limited herein.

According to the derivation of the formula in the first inductor structure, it can be further derived that the multiple paths of indirectly coupled inductors can realize negative coupling among the multiple paths of inductors.

Fig. 4 is a simulation waveform of a second inductor structure provided by the present invention. As shown in fig. 4, the four curves represent the current levels of the four first windings in turn, and it can be seen that, since the paths are indirectly coupled together, the current variation of a single path is affected by the currents of other paths. The equivalent inductance of each path of winding is the same, the current of one path of winding changes, other paths can also respond to the change quickly, and current sharing among the paths is easier to realize when the load suddenly changes.

Fig. 5 is a schematic diagram of a third inductor structure according to the present invention. As shown in fig. 5, the main difference between the third inductance structure and the first inductance structure is that the number of the first windings 311 is smaller than the number of the magnetic core legs 302, that is, there are magnetic core legs 303 which are not wound by the first windings 311. In this embodiment, there are 2 magnetic core legs 303 which are not wound by the first winding, and are located at both sides of the magnetic core legs. Of course, in other embodiments, the core leg 303 not wound by the first winding may be any one, and may be located at a middle position of the substrate 301, or may be located at two sides, that is, may be located at any position on the substrate 301, which is not limited herein. The magnetic core columns of the present embodiment may be arranged in a row side by side, or may be arranged in two rows, and the arrangement manner thereof may be set by those skilled in the art according to the needs, which is not limited herein.

In addition, a core leg not wound by the first winding may be made of the same magnetic powder core material as the second magnetic core 331.

The second winding of the embodiment forms additional inductance in the magnetic powder core structure, increases the inductance of the second winding, and is more convenient for adjusting the current ripple in the inductance and the coupling coefficient between the windings.

The above description is only of the preferred embodiments of the present invention and is not intended to limit the present invention, and various modifications and variations may be made to the present invention by those skilled in the art. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A power converter, comprising:

an inductance structure including first to nth inductance coils, and a coupling coil;

each path of the inductance coil and the corresponding transistor form a power stage circuit so as to generate an output signal at the output end of the power stage circuit;

The coupling coil and each path of inductance coil form a negative coupling relationship, and the coupling relationship between the coupling coil and the inductance coils is stronger than that between any two paths of inductance coils.

2. The power converter of claim 1 wherein any two of said inductor coils are in a negative coupling relationship and wherein a coupling coefficient between said coupling coil and said inductor coils is greater than a coupling coefficient between any two of said inductor coils.

3. The power converter of claim 1, wherein the input of each of said power stage circuits receives the same input voltage source, and the output of each of said power stage circuits generates said output signal.

4. The power converter of claim 1, wherein the inductive structure comprises:

a first magnetic core comprising a substrate and at least two magnetic core legs positioned on the substrate;

At least two first windings, each first winding being wound around one of the magnetic core limbs, any two of the at least two first windings being separated from each other to form the inductor; and

And the second windings are wound on at least two magnetic core columns and are positioned above the first windings to form the coupling coil.

5. An inductor structure, comprising:

At least two first windings, each of which is wound with one magnetic core column, and a space exists between any two of the at least two first windings; and

A second winding wound around the at least two magnetic core legs; the second winding and each first winding form a negative coupling relationship, and the coupling coefficient between the second winding and any one of the at least two first windings is larger than the coupling coefficient between two adjacent first windings.

6. The inductive structure of claim 5, further comprising a second magnetic core on said substrate, encasing said at least two first windings, said second windings and said first magnetic core.

7. The inductance structure according to claim 5, wherein the number of the first windings is equal to or less than the number of the core legs.

8. The inductance structure according to claim 6, wherein said second magnetic core and said first magnetic core are magnetic powder cores of the same material.

9. An inductive structure according to claim 6, wherein the second magnetic core and the first magnetic core are magnetic powder cores of different materials.

10. The inductive structure of claim 9, wherein a magnetic permeability of said first magnetic core is greater than a magnetic permeability of said second magnetic core.

11. The inductance structure according to claim 6, wherein when the number of the core legs is greater than the number of the first windings, the core legs not wound by the first windings are made of the same material as the second core.

12. The inductive structure of claim 5, wherein said core legs are arranged side-by-side.

13. The inductive structure of claim 5, wherein said core legs are arranged in a plurality of rows.

14. The inductive structure of claim 5, wherein the outgoing lines of said first winding are located on the same side of said substrate.

15. The inductive structure of claim 5, wherein the outgoing lines of said first winding are located on different sides of said substrate.

16. The inductive structure of claim 5, wherein said second winding is located above said first winding.