Inductor, power conversion circuit, switching power supply and electronic equipment

Abstract

The embodiment of the invention provides an inductor, a power conversion circuit, a switching power supply and electronic equipment, and relates to the technical field of electronics. The inductor comprises a magnetic core, wherein the magnetic core comprises a first middle column and a second middle column; the primary winding is arranged around the first middle column; the secondary winding is arranged around the first middle column and the second middle column, and the primary winding is arranged between the first middle column and the secondary winding. According to the inductor, the compensation inductor is integrated in the inductor, so that when the inductor is applied to a switching power supply, the circuit area of the switching power supply can be reduced.

Description

Technical Field

[0001] Embodiments of the present application relate to the field of electronic technologies, and in particular, to an inductor, a power conversion circuit, a switching power supply, and an electronic device. Background Art

[0002] Switching power supplies are widely used in chip power supply for various electronic products, especially mobile devices such as mobile phones and laptop computers. Especially with the continuous growth of computing power, the power supply layout is becoming increasingly tight. Therefore, there is a very strong demand for miniaturization of switching power supplies. Summary of the Invention

[0003] Embodiments of the present application provide an inductor, a power conversion circuit, a switching power supply, and an electronic device, which integrate a compensation inductor inside the inductor, so that when the inductor is applied to a switching power supply, the layout area of the switching power supply can be reduced.

[0004] To achieve the above object, embodiments of the present application adopt the following technical solutions:

[0005] In a first aspect, an inductor is provided. The inductor includes: a magnetic core, the magnetic core includes a first middle column and a second middle column; a primary winding, the primary winding is wound around the first middle column; a secondary winding, the secondary winding is wound around the first middle column and the second middle column, and the primary winding is disposed between the first middle column and the secondary winding.

[0006] The inductor provided in this embodiment winds the primary winding around the first middle column, and winds the secondary winding around the first middle column and the second middle column, and the primary winding is disposed between the first middle column and the secondary winding. When current passes through the primary winding, magnetic fields are generated in both the first middle column and the second middle column. The magnetic field generated in the first middle column passes through the primary winding and the secondary winding, and an electromotive force is generated in the secondary winding. The magnetic field generated in the second middle column does not link with the primary winding, and a leakage inductance that is not coupled is constructed in the secondary winding and the primary winding. The leakage inductance is integrated as a compensation inductor inside the inductor. When applied to a power conversion circuit, it can adjust the response speed and stability of the power supply, and reduce the board area and manufacturing cost of the power conversion circuit.

[0007] In an exemplary embodiment, the magnetic core includes a first structural member and a second structural member. The first structural member includes a first bottom plate and a first column disposed on the first bottom plate; the second structural member includes a second bottom plate and a second column disposed on the second bottom plate; the free end of the first column contacts the free end of the second column to form the first middle column; the first structural member further includes a third column disposed on the first bottom plate; and a fourth column disposed on the second bottom plate, and the free end of the third column is opposite to the free end of the fourth column to form the second middle column. Thereby, the length of the magnetic path can be increased, and thus the induction effect of the inductor can be improved.

[0008] In an exemplary embodiment, a paste material layer is provided between the free ends of the third cylinder and the fourth cylinder, and voids are included in the paste material layer.

[0009] In this embodiment, when the paste material layer contains air gaps, the magnetic field generated in the second middle column can be further prevented from cross-linking with the primary winding, reducing the coupling coefficient between the primary winding and the secondary winding. Thus, the leakage inductance in the inductor can be adjusted by adjusting the size of the voids in the paste material layer. When there are no air gaps between the free ends of the third cylinder and the fourth cylinder, the coupling coefficient between the primary winding and the secondary winding is the largest.

[0010] In an exemplary embodiment, the magnetic core includes a first structural member and a cover plate. The first structural member includes a bottom plate, a first middle column, and a second middle column provided on the bottom plate; the cover plate contacts the free end of the first middle column and faces the free end of the second middle column.

[0011] In an exemplary embodiment, a paste material layer is provided between the free end of the cover plate and the free end of the second middle column, and voids are included in the paste material layer.

[0012] In this embodiment, when the paste material layer contains air gaps, the magnetic field generated in the second middle column can be further prevented from cross-linking with the primary winding, reducing the coupling coefficient between the primary winding and the secondary winding. Thus, the leakage inductance in the inductor can be adjusted by adjusting the size of the voids in the paste material layer. When there are no air gaps between the free ends of the third cylinder and the fourth cylinder, the coupling coefficient between the primary winding and the secondary winding is the largest.

[0013] In an exemplary embodiment, the magnetic core includes a first structural member and a second structural member. The first structural member includes a first bottom plate and a second middle column provided on the first bottom plate; the second structural member includes a second bottom plate and a first middle column provided on the second bottom plate; the first bottom plate faces the free end of the first middle column; the second bottom plate contacts the free end of the second middle column.

[0014] In an exemplary embodiment, a paste material layer is provided between the free end of the second bottom plate and the free end of the second middle column, and voids are included in the paste material layer.

[0015] In this embodiment, when the paste material layer contains air gaps, the magnetic field generated in the second middle column can be further prevented from cross-linking with the primary winding, reducing the coupling coefficient between the primary winding and the secondary winding. Thus, the leakage inductance in the inductor can be adjusted by adjusting the size of the voids in the paste material layer. When there are no air gaps between the free ends of the third cylinder and the fourth cylinder, the coupling coefficient between the primary winding and the secondary winding is the largest.

[0016] In an exemplary embodiment, the magnetic core includes a bottom plate and a cover plate. A first central column and a second central column are provided on the bottom plate, and the first central column and the second central column are in contact with the cover plate; the bottom plate, the first central column, the second central column, and the cover plate are integrally formed.

[0017] In an exemplary embodiment, the primary winding includes a first end and a second end. Both the first end and the second end of the primary winding are located on a first side of the magnetic core. The first side is the side closer to the first central column in the arrangement direction of the first central column and the second central column; the secondary winding includes a first end and a second end. Both the first end and the second end of the secondary winding are located on the first side of the magnetic core.

[0018] In an exemplary embodiment, the primary winding includes a first end and a second end. Both the first end and the second end of the primary winding are located on a first side of the magnetic core. The first side is one side in the arrangement direction of the first central column and the second central column; the secondary winding includes a first end and a second end. Both the first end and the second end of the secondary winding are located on the first side of the magnetic core.

[0019] In an exemplary embodiment, the magnetic core further includes a third central column. The secondary winding is wound around the first central column, the second central column, and the third central column, and the primary winding is disposed between the first central column and the secondary winding.

[0020] In an exemplary embodiment, the cross-sectional area of the first central column is larger than that of the second central column. Thus, it can be ensured that energy can be transferred from one primary winding to the secondary winding while maintaining relative signal isolation.

[0021] In an exemplary embodiment, at least one of the primary winding and the secondary winding is a film-covered wire. Thus, electrical isolation between the primary winding and the secondary winding is achieved.

[0022] In an exemplary embodiment, the film-covered wire includes a core layer and a film layer covering the core layer. The core layer includes a metal material, and the film layer includes an insulating material. Thus, electrical isolation between the primary winding and the secondary winding is achieved.

[0023] In an exemplary embodiment, the magnetic core further includes side columns. A part of the secondary winding is disposed between the side columns and the first central column. Thus, a complete magnetic circuit can be formed inside the magnetic core.

[0024] In a second aspect, a power conversion circuit is provided. The power conversion circuit includes a switching circuit and an inductor; the inductor and the switching circuit are electrically connected.

[0025] In a third aspect, a switching power supply is provided. The switching power supply includes a control circuit and a power conversion circuit; the control circuit is electrically connected to the power conversion circuit.

[0026] Fourthly, an electronic device is provided. The electronic device includes: a load and a switching power supply, and the switching power supply is electrically connected to the load.

[0027] Among them, for the technical effects brought by any one of the possible implementation manners in the second to fourth aspects, reference may be made to the technical effects brought by different implementation manners in the first aspect above, which will not be elaborated herein. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 Schematic diagram of the structure of the electronic device provided by the embodiment of the present application;

[0029] Figure 2 Schematic diagram of the structure of the electronic device provided by the embodiment of the present application;

[0030] Figure 3 Schematic diagram of the power conversion circuit provided by the embodiment of the present application;

[0031] Figure 4 Schematic diagram of the power conversion circuit provided by another embodiment of the present application;

[0032] Figure 5 Schematic diagram of the structure of the inductor provided by the embodiment of the present application;

[0033] Figure 6 Schematic diagram of the structure of the inductor provided by another embodiment of the present application;

[0034] Figure 7 Schematic diagram of the equivalent inductor provided by the embodiment of the present application;

[0035] Figure 8 Schematic diagram of the structure of the inductor provided by the embodiment of the present application;

[0036] Figure 9 Schematic diagram of the structure of the inductor provided by the embodiment of the present application;

[0037] Figure 10 Schematic diagram of the power conversion circuit provided by the embodiment of the present application;

[0038] Figure 11 Schematic diagram of the structure of the inductor provided by the embodiment of the present application;

[0039] Figure 12 Schematic diagram of the structure of the inductor provided by the embodiment of the present application;

[0040] Figure 13 Schematic diagram of the structure of the inductor provided by the embodiment of the present application;

[0041] Figure 14 Schematic diagram of the structure of the inductor provided by the embodiment of the present application;

[0042] Figure 15 It is a schematic structural diagram of the inductor provided by the embodiment of the present application;

[0043] Figure 16 It is a schematic structural diagram of the inductor provided by the embodiment of the present application;

[0044] Figure 17 It is a schematic structural diagram of the inductor provided by the embodiment of the present application;

[0045] Figure 18 It is a schematic structural diagram of the inductor provided by the embodiment of the present application. Detailed implementation manners

[0046] Next, the technical solutions in the embodiments of the present application will be described in conjunction with the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments.

[0047] Hereinafter, terms such as "first" and "second" are only used for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, features defined with "first", "second", etc. may explicitly or implicitly include one or more of such features.

[0048] In addition, in the present application, orientation terms such as "upper" and "lower" are defined relative to the orientation of the components shown in the drawings. It should be understood that these directional terms are relative concepts, which are used for relative description and clarification, and they may change accordingly with the change of the orientation of the components placed in the drawings.

[0049] In the present application, unless otherwise clearly defined and limited, the term "connection" should be understood in a broad sense. For example, "connection" can be a fixed connection, a detachable connection, or an integral one; it can be directly connected, or indirectly connected through an intermediate medium. In addition, the term "coupling" can be a way of realizing electrical connection for signal transmission, and "coupling" can be a direct electrical connection, or an indirect electrical connection through an intermediate medium.

[0050] The embodiment of the present application provides an electronic device, which includes electronic devices with functions such as processing, computing, and communication, such as mobile phones, tablet computers, in-vehicle computers, smart wearable products, servers, switches, and computers. The embodiment of the present application does not impose special restrictions on the specific form of the above-mentioned electronic devices.

[0051] For the convenience of description below, a mobile phone is taken as an example of the electronic device for illustration. As Figure 1 shown, the electronic device 01 includes a display module 10, a middle frame 11, and a rear shell 12.

[0052] The display module 10 is used to display images. In some embodiments of the present application, the display module 10 includes a liquid crystal display (LCD) module and a backlight unit (BLU). Alternatively, in some other embodiments of the present application, the display module 10 may be an organic light emitting diode (OLED) display screen.

[0053] The middle frame 11 is located between the display module 10 and the rear case 12. One side of the middle frame 11 facing the display module 10 is used to carry the display module 10. In addition, the above-mentioned electronic device 01 further includes a printed circuit board (PCB). One side surface of the middle frame 11 facing the rear case 12 is used to carry electronic components such as the PCB, camera, and battery. Among them, the camera and the battery are not shown in the figure. The rear case 12 is connected to the middle frame 11 to form a receiving cavity for accommodating the above-mentioned electronic components such as the PCB, camera, and battery. Thereby, it is possible to prevent external moisture and dust from invading the receiving cavity and affecting the performance of the above-mentioned electronic components.

[0054] In some examples, as Figure 2 shown, the electronic device 01 may include a switching power supply 20 and a load 30. The switching power supply 20 and the load 30 are connected through a circuit pattern on the above-mentioned printed circuit board PCB. Among them, the input end of the switching power supply 20 can be electrically connected to a power supply outside the electronic device. Exemplarily, the external power supply can be an AC power supply or a DC power supply. The output end of the switching power supply 20 can be electrically connected to the load 30, so that the AC power supply can supply power to the load 30 through the switching power supply 20. Exemplarily, the AC power supply can be mains power or a diesel generator, etc.

[0055] Exemplarily, the load 30 may include a processing chip, such as a system on chip (SoC), a central processing unit (English full name: central processing unit, English abbreviation: CPU), or a graphics processing unit (English full name: graphics processing unit, English abbreviation: GPU), etc. The switching power supply 20 can convert the AC voltage provided by the AC power supply into a stable DC voltage, so that the load 30 can operate normally. In some examples, the voltage value at the output end of the switching power supply 20 can change with the change of the operating power of the load 30 to meet the operating requirements of the load 30 under different working conditions.

[0056] In addition, as Figure 2As shown, the switching power supply 20 includes a power conversion circuit 23 and a control circuit 24. The power conversion circuit 23 and the control circuit 24 can be disposed on the above-mentioned PCB, and the control circuit 24 is used to control the power conversion circuit 23. The power conversion circuit 23 is used to convert the voltage of the power supply outside the electronic device 01, and after, for example, step-down or step-up processing, it is provided as the working voltage to each of the above-mentioned loads 30. The power conversion circuit 23 can be a buck (BUCK) circuit.

[0057] For the convenience of description below, the power conversion circuit 23 is taken as an example of a buck (BUCK) circuit for illustration.

[0058] Among them, the power conversion circuit 23 includes a multi-phase buck circuit 21 and a capacitor Co. Each phase of the buck circuit 21 includes a switching circuit 22 and an inductor L1. As Figure 3 shown, a BUCK circuit is provided. The power conversion circuit includes: a multi-phase buck circuit 21 and a capacitor Co. Each phase of the buck circuit 21 is connected in parallel. Among them, each phase of the buck circuit 21 includes a switching circuit 22 (including: a first switching transistor Q1 and a second switching transistor Q2) and an inductor L1. The first switching transistor Q1 and the second switching transistor Q2 can be transistors. The first pole of the first switching transistor Q1, for example, the source (source, s), is coupled to the input terminal Vin of the BUCK circuit. The input terminal Vin of the BUCK circuit can be coupled to a power supply, for example, the positive electrode of a battery. The second pole of the first switching transistor Q1, for example, the drain (drain, d), is coupled to the first end of the inductor L1. The gate (gate, g) of the first switching transistor Q1 is used to receive the first control signal sent by the control circuit, and this first control signal can control the conduction and cut-off of the first switching transistor Q1. The first pole of the second switching transistor Q2, for example, the source s, is coupled to the first end of the inductor L1. The second pole of the second switching transistor Q2, for example, the drain d, is coupled to a power supply, for example, the negative electrode of the above-mentioned battery. The gate (gate, g) of the second switching transistor Q2 is used to receive the second control signal sent by the control circuit, and this second control signal can control the conduction and cut-off of the second switching transistor Q2. The second end of the inductor L1 is coupled to the output terminal Vout of the BUCK circuit. The first end of the capacitor Co is coupled to the output terminal Vout of the BUCK circuit, and the second end is coupled to a power supply, for example, the negative electrode of the above-mentioned battery. The inductor L1 has the functions of energy storage and filtering. When the first switching transistor Q1 is conducting and the second switching transistor Q2 is cut off, the power supply charges the inductor L1. When the first switching transistor Q1 is cut off and the second switching transistor Q2 is conducting, the inductor L1 discharges and continuously provides a stable working voltage to each load through the capacitor Co.

[0059] Above Figure 3In the provided solution, the first switching transistor Q1 and the second switching transistor Q2 are both described by taking NMOS as an example. Of course, in other solutions, the first switching transistor Q1 and the second switching transistor Q2 can both use PMOS, or both use NMOS; or one of the first switching transistor Q1 and the second switching transistor Q2 uses NMOS and the other uses PMOS.

[0060] When the first switching transistor Q1 uses PMOS and the second switching transistor Q2 uses PMOS, compared with Figure 3 the difference is that the source s of the second switching transistor Q2 should be coupled to the drain d of the first switching transistor Q1, and the drain d of the second switching transistor Q2 should be coupled to the power supply, such as the negative electrode of the above-mentioned battery. When the first switching transistor Q1 uses PMOS and the second switching transistor Q2 uses NMOS, compared with Figure 3 the difference is that the source of the first switching transistor Q1 is coupled to Vin, the drain of the first switching transistor Q1 is coupled to the drain of the second switching transistor Q2, and the source of the second switching transistor Q2 is coupled to the power supply, such as the negative electrode of the above-mentioned battery.

[0061] When the first switching transistor Q1 uses NMOS and the second switching transistor Q2 uses PMOS, compared with Figure 3 the difference is that the drain d of the first switching transistor Q1 is coupled to the input terminal Vin of the BUCK circuit, and the source s of the first switching transistor Q1 is coupled to the first end of the inductor L1. The source s of the second switching transistor Q2 is coupled to the source s of the first switching transistor Q1, and the drain d of the second switching transistor Q2 is coupled to the power supply, such as the negative electrode of the above-mentioned battery.

[0062] In addition, usually, the switching transistor in the BUCK circuit can also be replaced with a diode D. In this way, compared with Figure 3 the difference is that the cathode (cathode, c) of the diode D is coupled to the first end of the inductor L1, and the anode (anode, a) is coupled to the power supply, such as the negative electrode of the above-mentioned battery.

[0063] It can be understood that those skilled in the art can set each part in the switching circuit according to requirements, and this application does not limit it here.

[0064] However, with the continuous evolution of the requirements for switching power supplies, for example, the requirement for the dynamic response speed of the power supply of the switching power supply has been increased from 1000A / us to 2000A / us. Affected by ripple and efficiency, the output inductor L1 of the traditional power conversion circuit is difficult to reduce, and its dynamic performance has approached the limit.

[0065] Therefore, the embodiment of this application also provides a power conversion circuit. This power conversion circuit is based on the trans-inductor voltage regulator (TLVR) topology. As Figure 4As shown in the figure, the power conversion circuit includes: an n-phase buck circuit, a compensation inductor L0, and a capacitor Co. Each phase of the buck circuit is connected in parallel. Among them, each phase of the buck circuit includes a switching circuit 22 (including: a first switching transistor Q1 and a second switching transistor Q2) and a dual-winding coupled inductor L2. The first switching transistor Q1 and the second switching transistor Q2 can be transistors. The first pole of the first switching transistor Q1, such as the source (s), is coupled to the input terminal Vin of the BUCK circuit, and the input terminal Vin of the BUCK circuit can be coupled to a power source, such as the positive electrode of a battery. The second pole of the first switching transistor Q1, such as the drain (d), is coupled to the first end of the dual-winding coupled inductor L2. The gate (g) of the first switching transistor Q1 is used to receive a first control signal sent by a control circuit, and this first control signal can control the conduction and cutoff of the first switching transistor Q1. The first pole of the second switching transistor Q2, such as the source s, is coupled to the first end of the dual-winding coupled inductor L2, and the second pole of the second switching transistor Q2, such as the drain d, is coupled to a power source, such as the negative electrode of the above-mentioned battery. The gate (g) of the second switching transistor Q2 is used to receive a second control signal sent by the control circuit, and this second control signal can control the conduction and cutoff of the second switching transistor Q1. The second end of the dual-winding coupled inductor L2 is coupled to the output terminal Vout of the BUCK circuit. The third end of the dual-winding coupled inductor L2 in the first-phase buck circuit is grounded, the fourth end of the dual-winding coupled inductor L2 in the i-th (i = 1, 2, 3....n - 1) phase buck circuit is connected to the third end of the dual-winding coupled inductor L2 in the (i + 1)-th phase buck circuit, and the fourth end of the dual-winding coupled inductor L2 in the n-th phase buck circuit is grounded. The first end of the capacitor Co is coupled to the output terminal Vout of the BUCK circuit, and the second end is coupled to a power source, such as the negative electrode of the above-mentioned battery.

[0066] In this embodiment, the inductor in the BUCK circuit is replaced with a dual-winding coupled inductor L2 similar to a transformer with double windings. An ordinary inductor has only one set of windings, while the dual-winding coupled inductor L2 has two mutually coupled windings. Exemplarily, refer to Figure 5 , the dual-winding coupled inductor L2 includes: a magnetic core, and the magnetic core includes a central leg 10; a primary winding 110, and the primary winding 110 is wound around the central leg 101; a secondary winding 120, and the secondary winding 120 is wound around the central leg 101, and the primary winding 110 is arranged between the central leg and the secondary winding 120. When both the primary winding 110 and the secondary winding 120 are energized, a magnetic field is generated in the central leg 101. The secondary winding 120 and the central leg 101 act together to form a secondary inductor, and the primary winding 110 and the central leg 101 act together to form a primary inductor.

[0067] When applying the dual-winding coupled inductor L2 to a buck circuit, the third terminal of the dual-winding coupled inductor L2 in the first-phase buck circuit needs to be grounded, the fourth terminal of the dual-winding coupled inductor L2 in the i-th (i = 1, 2, 3....n-1) phase buck circuit is connected to the third terminal of the dual-winding coupled inductor L2 in the (i + 1)-th phase buck circuit, and the fourth terminal of the dual-winding coupled inductor L2 in the n-th phase buck circuit is grounded, so that the secondary inductors of all the dual-winding coupled inductors L2 are connected in series. This makes the connection between the buck circuits of each phase the strongest and can significantly improve the dynamic response speed. However, in order to adjust the response speed and stability of the power supply, an additional compensation inductor L0 needs to be added to the coupling path of the secondary inductor. The operating frequency of this inductor is the product of the number of phases and the switching frequency, which will bring relatively high additional losses and increase the board area and cost.

[0068] For this reason, an embodiment of the present application provides an inductor. Refer to Figure 6 , the inductor includes: a magnetic core 100, the magnetic core 100 includes a first central column 102 and a second central column 103; a primary winding 110, the primary winding 110 is wound around the first central column 102; a secondary winding 120, the secondary winding 120 is wound around the first central column 102 and the second central column 103, and the primary winding 110 is arranged between the first central column 102 and the secondary winding 120.

[0069] The inductor provided by the embodiment of the present application winds the primary winding 110 around the first central column 102, and winds the secondary winding 120 around the first central column 102 and the second central column 103, and the primary winding 110 is arranged between the first central column 102 and the secondary winding 120. When current passes through the primary winding 110, magnetic fields are generated in both the first central column 102 and the second central column 103. The magnetic field generated in the first central column 102 passes through the primary winding 110 and the secondary winding 120, and an electromotive force is generated in the secondary winding 120. The magnetic field generated in the second central column 103 is not cross-linked with the primary winding 110, and a leakage inductance that does not couple is constructed in the secondary winding 120 and the primary winding 110. The leakage inductance is integrated as the compensation inductor L0 inside the inductor. When applied to a power conversion circuit, it can adjust the response speed and stability of the power supply, and reduce the board area and manufacturing cost of the power conversion circuit.

[0070] Correspondingly, the equivalent circuit diagram corresponding to the inductor is as shown in Figure 7As shown. When both the primary winding 110 and the secondary winding 120 are energized, magnetic fields are generated in both the first middle leg 102 and the second middle leg 103. The secondary winding 120, the first middle leg 102, and the second middle leg 103 act together to form a secondary inductor, and the primary winding 110 and the first middle leg 102 act together to form a primary inductor. Among them, the secondary inductor and the primary inductor constitute an inductor L3. The secondary leakage inductance generated by the secondary winding is equivalent to an inductor L4 connected in series with the secondary inductor, and the primary leakage inductance generated by the primary winding is equivalent to an inductor L5 connected in series with the primary inductor. Compared with Figure 4 the inductor L2 in, when the inductor L3 provided in this embodiment is applied to a power conversion circuit, it is not necessary to connect a compensation inductor L0 in series on the coupling path of the secondary inductor, and the power supply requirements can be met, thereby reducing the board area and manufacturing cost of the power conversion circuit.

[0071] In an alternative embodiment, referring to Figure 8 , the inductor includes a magnetic core 100. The magnetic core 100 includes a first structural member 130 and a second structural member 140. The first structural member 130 includes a first bottom plate 131 and a first column 104 disposed on the first bottom plate 131; the second structural member 140 includes a second bottom plate 141 and a second column 106 disposed on the second bottom plate 141; the free end of the first column 104 contacts the free end of the second column 106 to form the first middle leg 102; the first structural member 130 further includes a third column 105 disposed on the first bottom plate 131; and a fourth column 107 disposed on the second bottom plate 141. The free end of the third column 105 faces the free end of the fourth column 107 to form the second middle leg 103. The primary winding 110 is wound around the first middle leg 102; the secondary winding 120 is wound around the first middle leg 102 and the second middle leg 103, and the primary winding 110 is disposed between the first middle leg 102 and the secondary winding 120.

[0072] In this embodiment, the magnetic core 100 includes a first structural member 130 and a second structural member 140. The free end of the first column 104 disposed in the first structural member 130 contacts the free end of the second column 106 disposed in the second structural member 140 to form the first middle leg 102, and the free end of the third column 105 disposed in the first structural member 130 faces the free end of the fourth column 107 disposed in the second structural member 140 to form the second middle leg 103, thereby increasing the length of the magnetic path and improving the induction effect of the inductor.

[0073] In an alternative embodiment, referring to Figure 9 , wherein Figure 9 is Figure 8The screenshot in the AA' plane, a paste material layer 150 is provided between the free ends of the third cylinder 105 and the fourth cylinder 107, and voids are included in the paste material layer 150. Exemplarily, the material of the paste material layer 150 can be glue containing solid particles of a specific size. By containing solid particles of a specific size, voids can be made to be included in the paste material layer 150. When air gaps are included in the paste material layer 150, the magnetic field generated in the second middle cylinder 103 can be further prevented from cross-linking with the primary winding 110, reducing the coupling coefficient between the primary winding 110 and the secondary winding 120. It can be understood that the leakage inductance in the inductor can be adjusted by adjusting the size of the voids in the paste material layer 150. There are no air gaps between the free ends of the third cylinder 105 and the fourth cylinder 107, and at this time, the coupling coefficient between the primary winding 110 and the secondary winding 120 is the largest.

[0074] For example, in Figure 4 the power conversion circuit shown, in order to adjust the response speed and stability of the switching power supply, a compensation inductor L0 needs to be connected in series on the secondary inductor coupling path. Exemplarily, Figure 4 in the power conversion circuit shown, the inductance of the compensation inductor L0 is 75 nH. In the embodiments of the present application, the leakage inductance of the inductor can be controlled by controlling the size of the voids. Exemplarily, as Figure 10 shown, when the power conversion circuit is provided with multiple inductors L3, for example, when three inductors L3 are included, the leakage inductance of the inductor L3 can be controlled by controlling the size of the voids so that the leakage inductance of the inductor L3 is 25 nH, and thus the total leakage inductance of the three inductors L3 is 75 nH, which can replace the compensation inductor L0 to improve the stability of the switching power supply.

[0075] In an alternative embodiment, the cross-sectional area of the first middle cylinder 102 of the inductor is larger than the cross-sectional area of the second middle cylinder 103 to ensure that energy can be transmitted from one primary winding 110 to the secondary winding 120 while maintaining relative signal isolation.

[0076] In an alternative embodiment, at least one of the primary winding 110 and the secondary winding 120 is a film-covered wire. Exemplarily, the film-covered wire includes a core layer and a film layer covering the core layer. The core layer includes a metal material. For example, the core layer is a copper wire, and the film layer includes an insulating material. Exemplarily, the primary winding 110 can be a film-covered wire and the secondary winding 120 can be a copper wire; or, the primary winding 110 can be a copper wire and the secondary winding 120 can be a film-covered wire; or, both the primary winding 110 and the secondary winding 120 can be film-covered wires.

[0077] The material of the magnetic core 100 can be soft ferrite or metal soft magnetic powder core. Thus, the magnetic core 100 can have a relatively high magnetic permeability, which means it can effectively conduct magnetic fields and store and release energy in the magnetic field. The high magnetic permeability helps improve the efficiency and performance of the inductor.

[0078] In an alternative embodiment, referring to Figure 11 , the inductor includes: a magnetic core 100, the magnetic core 100 includes a first structural member 130 and a cover plate 141, the first structural member 130 includes a bottom plate 131 and a first middle column 102 and a second middle column 103 disposed on the bottom plate 131; the cover plate 141 contacts the free end of the first middle column 102 and is opposite to the free end of the second middle column 103. A primary winding 110, the primary winding 110 is wound around the first middle column 102; a secondary winding 120, the secondary winding 120 is wound around the first middle column 102 and the second middle column 103, and the primary winding 110 is disposed between the first middle column 102 and the secondary winding 120.

[0079] In this embodiment, the magnetic core 100 includes a first structural member 130 and a cover plate 141. The first structural member 130 includes a bottom plate 131 and a first middle column 102 and a second middle column 103 disposed on the bottom plate 131. The bottom plate 131 and the cover plate 141 provide a transmission channel for the magnetic field coupling between the primary winding 110 and the secondary winding 120. At the same time, the bottom plate 131 and the cover plate 141 can also protect the primary winding 110 and the secondary winding 120 from external environmental interference and improve the stability of the inductor.

[0080] In an alternative embodiment, referring to Figure 12 , wherein, Figure 12 is Figure 11 a screenshot in the AA' plane. A paste material layer 150 is disposed between the cover plate 141 and the free end of the second middle column 103, and the paste material layer 150 includes voids. Exemplarily, the material of the paste material layer 150 can be glue containing solid particles of a specific size. By containing solid particles of a specific size, voids can be made to be included in the paste material layer 150. When the paste material layer 150 contains air gaps, the magnetic field in the second middle column 103 that does not cross-link with the primary winding 110 can be further increased, reducing the coupling coefficient between the primary winding 110 and the secondary winding 120. It can be understood that the size of the leakage inductance in the inductor can be adjusted by adjusting the size of the voids in the paste material layer 150. There is no air gap between the free end of the third column 105 and the free end of the fourth column 107. At this time, the coupling coefficient between the primary winding 110 and the secondary winding 120 is the largest.

[0081] In an alternative embodiment, as Figure 13As shown, the inductor includes a magnetic core 100, which includes a first structural member 130 and a second structural member 140. The first structural member 130 includes a first bottom plate 131 and a second middle column 103 disposed on the bottom plate 131; the second structural member 140 includes a second bottom plate 141 and a first middle column 102 disposed on the second bottom plate 141; the first bottom plate 131 is opposite to the free end of the first middle column 102; the second bottom plate 141 is in contact with the free end of the second middle column 103. A primary winding 110 is disposed around the first middle column 102; a secondary winding 120 is disposed around the first middle column 102 and the second middle column 103, and the primary winding 110 is disposed between the first middle column 102 and the secondary winding 120.

[0082] In this embodiment, the magnetic core 100 includes a first structural member 130 and a second structural member 140. The first structural member 130 includes a first bottom plate 131 and a second middle column 103 disposed on the bottom plate 131; the second structural member 140 includes a second bottom plate 141 and a first middle column 102 disposed on the second bottom plate 141. The first bottom plate 131 and the second bottom plate 141 provide a transmission channel for magnetic field coupling between the primary winding 110 and the secondary winding 120. At the same time, the first bottom plate 131 and the second bottom plate 141 can also protect the primary winding 110 and the secondary winding 120 from external environmental interference and improve the stability of the inductor.

[0083] In an alternative embodiment, refer to Figure 14 , wherein, Figure 14 is Figure 13 a screenshot in the AA' plane. A paste material layer 150 is disposed between the second bottom plate 141 and the free end of the first middle column 102, and the paste material layer 150 includes voids. Exemplarily, the material of the paste material layer 150 can be glue containing solid particles of a specific size. By containing solid particles of a specific size, voids can be included in the paste material layer 150. When the paste material layer 150 contains air gaps, the magnetic field in the second middle column 103 that does not cross-link with the primary winding 110 can be further increased, reducing the coupling coefficient between the primary winding 110 and the secondary winding 120. It can be understood that the size of the leakage inductance in the inductor can be adjusted by adjusting the size of the voids in the paste material layer 150. When there is no air gap between the second middle column 103 and the second bottom plate 141, the coupling coefficient between the primary winding 110 and the secondary winding 120 is the largest at this time.

[0084] In an alternative embodiment, the magnetic core 100 includes a bottom plate 131 and a cover plate 141. The first middle column 102 and the second middle column 103 are disposed on the bottom plate 131, and the first middle column 102 and the second middle column 103 are in contact with the cover plate 141; the bottom plate 131, the first middle column 102, the second middle column 103, and the cover plate 141 are integrally formed.

[0085] Compared with Figures 8 - 14 the inductor formed by assembling the magnetic core 100, in the embodiments of the present application, the bottom plate 131, the first middle column 102, the second middle column 103 and the cover plate 141 can be integrally formed by processes such as powder magnetic core integral molding and powder magnetic core injection molding. The integrally formed magnetic core 100 can ensure that the distances and relative positions between the various parts of the magnetic core 100 are very accurate, so the mutual interference and electromagnetic noise between the magnetic cores 100 can be effectively reduced.

[0086] In order to more flexibly adjust the leakage inductance of the inductor, the following embodiments provide several different setting methods for the first middle column 102 and the second middle column 103. The inductors provided in the following embodiments can all form the magnetic core by the assembling or integral molding methods provided in the foregoing embodiments.

[0087] In an alternative embodiment, as Figure 15 shown, wherein, Figure 15 the (1) in Figure 15 is the top view of the (2) in

[0088] This inductor includes: a magnetic core 100, the magnetic core 100 includes a first middle column 102 and a second middle column 103; a primary winding 110, the primary winding 110 is wound around the first middle column 102; a secondary winding 120, the secondary winding 120 is wound around the first middle column 102 and the second middle column 103, and the primary winding 110 is arranged between the first middle column 102 and the secondary winding 120. The primary winding 110 includes a first end and a second end, both the first end and the second end of the primary winding 110 are located on the first side of the magnetic core 100, and the first side is the side close to the first middle column 102 in the arrangement direction of the first middle column 102 and the second middle column 103. The secondary winding 120 includes a first end and a second end, and both the first end and the second end of the secondary winding 120 are located on the first side of the magnetic core 100.

[0089] In this embodiment, compared with Figure 5The inductor shown. In this embodiment, the middle column of the magnetic core 100 is divided into a first middle column 102 and a second middle column 103 arranged along the first direction. The primary winding 110 includes a first end and a second end. Both the first end and the second end of the primary winding 110 are located on the first side of the magnetic core 100, and the first end and the second end of the primary winding 110 are respectively located on both sides of the first middle column 102, so that the primary winding 110 can surround the first middle column 102. Exemplarily, the primary winding 110 is in a "ji" shape. The secondary winding 120 includes a first end and a second end. Both the first end and the second end of the secondary winding 120 are located on the first side of the magnetic core 100, and the first end and the second end of the secondary winding 120 are respectively located on both sides of the first middle column 102 and the second middle column 103, so that the secondary winding 120 is arranged to surround the first middle column 102 and the second middle column 103. Exemplarily, the secondary winding 120 is in a "kui" shape. The first end and the second end of the secondary winding 120 and the first end and the second end of the primary winding 110 are all located on the first side of the magnetic core 100. The first side is the side closer to the first middle column 102 in the arrangement direction of the first middle column 102 and the second middle column 103, so as to facilitate the access of the first end and the second end of the secondary winding 120 and the first end and the second end of the primary winding 110 to current.

[0090] When the first end and the second end of the primary winding 110 and the first end and the second end of the secondary winding 120 are all energized, magnetic fields are generated in both the first middle column 102 and the second middle column 103. The secondary winding 120 interacts with the first middle column 102 and the second middle column 103 to form a secondary inductor, and the primary winding 110 interacts with the first middle column 102 to form a primary inductor. The magnetic field generated in the first middle column 102 passes through the primary winding 110 and the secondary winding 120 and then forms a magnetic circuit through the side column 151, so as to generate an electromotive force in the secondary winding 120. The magnetic field generated by the second middle column 103 does not cross-link with the primary winding 110, and leakage inductance that does not couple is constructed in the secondary winding 120 and the primary winding 110. The leakage inductance is integrated as a compensation inductor L0 inside the inductor. When applied to a power conversion circuit, it can adjust the response speed and stability of the power supply, and reduce the board area and manufacturing cost of the power conversion circuit.

[0091] In another alternative embodiment, as Figure 16 shown, where Figure 16 in (1) is Figure 16The top view of (2) therein. The inductor includes: a magnetic core 100, and the magnetic core 100 includes a first middle column 102 and a second middle column 103; a primary winding 110, and the primary winding 110 is disposed around the first middle column 102; a secondary winding 120, and the secondary winding 120 is disposed around the first middle column 102 and the second middle column 103, and the primary winding 110 is disposed between the first middle column 102 and the secondary winding 120. The primary winding 110 includes a first end and a second end, and both the first end and the second end of the primary winding 110 are located on the first side of the magnetic core 100, and the first side is one side in the arrangement direction of the first middle column 102 and the second middle column 103; the secondary winding 120 includes a first end and a second end, and both the first end and the second end of the secondary winding 120 are located on the first side of the magnetic core 100.

[0092] Compared with Figure 5 the inductor shown, in the inductor of this embodiment, the middle column in the magnetic core 100 is divided into a first middle column 102 and a second middle column 103 arranged along the second direction. The primary winding 110 includes a first end and a second end, and both the first end and the second end of the primary winding 110 are located on the first side of the magnetic core 100, and the first end and the second end of the primary winding 110 are respectively located on both sides of the first middle column 102, so that the primary winding 110 can be disposed around the first middle column 102. Exemplarily, the primary winding 110 is in a "ji" shape. The secondary winding 120 includes a first end and a second end, and both the first end and the second end of the secondary winding 120 are located on the first side of the magnetic core 100, and the first end of the secondary winding 120 is located on the side of the first end of the primary winding 110 away from the first middle column 102, and the second end of the secondary winding 120 is located on the side of the second middle column 103 away from the first middle column 102, so that the secondary winding 120 is disposed around the first middle column 102 and the second middle column 103. Exemplarily, the secondary winding 120 is in a "kui" shape, and the first end, the second end of the secondary winding 120 and the first end, the second end of the primary winding 110 are all located on the first side of the magnetic core, and the first side is one side in the arrangement direction of the first middle column 102 and the second middle column 103. Compared with Figure 15 the first middle column 102 and the second middle column 103 longitudinally arranged along the first direction shown, the first middle column 102 and the second middle column 103 in this embodiment are arranged horizontally along the second direction. When the length of the magnetic core 100 in the second direction is greater than the length in the first direction, the area of the second middle column 103 can be set larger, so as to provide a larger leakage inductance.

[0093] It can be understood that the relative positional relationship between the first middle column 102 and the second middle column 103 in the embodiment of the present application can also be as shown in Figure 16 (3) therein, that is, the second middle column 103 can be located on the left or right side of the first middle column 102.

[0094] In another alternative embodiment, as shown in Figure 17As shown, wherein, Figure 17 (1) in Figure 17 is the top view of (2) in, and the inductor includes: a magnetic core 100, the magnetic core 100 includes a first middle column 102, a second middle column 103 and a third middle column; a primary winding 110, the primary winding 110 is disposed around the first middle column 102; a secondary winding 120, the secondary winding 120 is disposed around the first middle column 102, the second middle column 103 and the third middle column, and the primary winding 110 is disposed between the first middle column 102 and the secondary winding 120.

[0095] Figure 15 and Figure 16 The length of the second middle column 103 in the inductor shown depends on the size of the first middle column 102. Only by adjusting the width of the second middle column 103 can the leakage inductance of the inductor be adjusted. Limited by the segmentation process, however, a certain dimension of the second middle column 103, such as the width, cannot be further reduced to further reduce the cross-sectional area. Therefore, compared with Figure 15 and Figure 16 In the inductor shown, in this embodiment, the middle column in the magnetic core 100 is divided into a first middle column 102, a second middle column 103 and a third middle column 108. The secondary winding 120 is disposed around the first middle column 102, the second middle column 103 and the third middle column 108, and the primary winding 110 is disposed between the first middle column 102 and the secondary winding 120. Exemplarily, the first middle column 102 is in a "convex" shape. Wherein, the sizes of the second middle column 103 and the third middle column 108 can be flexibly set to further flexibly adjust the leakage inductance of the inductor.

[0096] It should be noted that, understandably, the above examples are only examples listed for better understanding the technical solutions of the embodiments of the present invention and do not serve as the sole limitation of the embodiments of the present invention. Those skilled in the art can select the segmentation method of the middle column according to the process level and the leakage inductance requirement. For example, in an optional example, refer to Figure 18 , the first middle column 102 is disposed around the second middle column 103. Thus, the leakage inductance of the inductor can be further reduced.

[0097] The inductor provided by the embodiment of the present application includes a bottom plate 131 and a magnetic core 100 disposed on the bottom plate 131. The magnetic core 100 includes a first middle column 102 and a second middle column 103. The primary winding 110 is wound around the first middle column 102, and the secondary winding 120 is wound around the first middle column 102 and the second middle column 103. The primary winding 110 is disposed between the first middle column 102 and the secondary winding 120. When current passes through the primary winding 110, magnetic fields are generated in both the first middle column 102 and the second middle column 103. After the magnetic field generated in the first middle column 102 passes through the primary winding 110 and the secondary winding 120, an electromotive force is generated in the secondary winding 120. The magnetic field generated in the second middle column 103 is not cross-linked with the primary winding 110, and a leakage inductance that does not couple is constructed in the secondary winding 120 and the primary winding 110. The leakage inductance is integrated as a compensation inductor L0 inside the inductor. And the magnitude of the leakage inductance of the inductor can be adjusted by flexibly adjusting the cross-sectional areas of the first middle column 102 and the second middle column 103. When applied to a power conversion circuit, the leakage inductance of the inductor can be used as the compensation inductor L0 to adjust the response speed and stability of the power supply. Since there is no need to provide an additional compensation inductor L0 in the power conversion circuit, the board area and manufacturing cost of the power conversion circuit are reduced.

[0098] The above is only the specific implementation manner of the present application, but the protection scope of the present application is not limited thereto. Any person skilled in the art within the technical scope disclosed by the present application can easily think of changes or substitutions, which should all be covered within the protection scope of the present application. Therefore, the protection scope of the present application shall be subject to the protection scope of the claims.

Claims

1. An inductor, characterized in that, it includes: a magnetic core, the magnetic core includes a first central leg and a second central leg; a primary winding, the primary winding is arranged around the first central leg; a secondary winding, the secondary winding is arranged around the first central leg and the second central leg, and the primary winding is arranged between the first central leg and the secondary winding.

2. The inductor according to claim 1, characterized in that, the magnetic core includes a first structural member and a second structural member, the first structural member includes a first bottom plate and a first column body arranged on the first bottom plate; the second structural member includes a second bottom plate and a second column body arranged on the second bottom plate; the free end of the first column body contacts the free end of the second column body to form the first central leg; the first structural member further includes a third column body arranged on the first bottom plate; and a fourth column body arranged on the second bottom plate, the free end of the third column body faces the free end of the fourth column body to form the second central leg.

3. The inductor according to claim 2, characterized in that, a bonding material layer is arranged between the free end of the third column body and the free end of the fourth column body, and the bonding material layer includes voids.

4. The inductor according to claim 1, characterized in that, the magnetic core includes a first structural member and a cover plate, the first structural member includes a bottom plate and the first central leg and the second central leg arranged on the bottom plate; the cover plate contacts the free end of the first central leg and faces the free end of the second central leg.

5. The inductor according to claim 4, characterized in that, a bonding material layer is arranged between the free end of the cover plate and the free end of the second central leg, and the bonding material layer includes voids.

6. The inductor according to claim 1, characterized in that, the magnetic core includes a first structural member and a second structural member, the first structural member includes a first bottom plate and the second central leg arranged on the first bottom plate; the second structural member includes a second bottom plate and the first central leg arranged on the second bottom plate; the first bottom plate faces the free end of the second central leg; the second bottom plate contacts the free end of the first central leg.

7. The inductor according to claim 6, characterized in that, a bonding material layer is arranged between the free end of the second bottom plate and the free end of the second central leg, and the bonding material layer includes voids.

8. The inductor according to claim 1, characterized in that, the magnetic core includes a bottom plate and a cover plate, the first central leg and the second central leg are arranged on the bottom plate, and the first central leg and the second central leg contact the cover plate; the bottom plate, the first central leg, the second central leg and the cover plate are integrally formed.

9. The inductor according to any one of claims 1-8, characterized in that, the primary winding includes a first end and a second end, the first end and the second end of the primary winding are both located on the first side of the magnetic core, and the first side is the side close to the first central leg in the arrangement direction of the first central leg and the second central leg; The secondary winding includes a first end and a second end, and both the first end and the second end of the secondary winding are located on the first side of the magnetic core.

10. The inductor according to any one of claims 1-8, wherein, the primary winding includes a first end and a second end, and both the first end and the second end of the primary winding are located on the first side of the magnetic core, and the first side is one side in the arrangement direction of the first middle leg and the second middle leg; the secondary winding includes a first end and a second end, and both the first end and the second end of the secondary winding are located on the first side of the magnetic core.

11. The inductor according to any one of claims 1-8, wherein, the magnetic core further includes a third middle leg 108, the secondary winding is disposed around the first middle leg, the second middle leg and the third middle leg 108, and the primary winding is disposed between the first middle leg and the secondary winding.

12. The inductor according to any one of claims 1-11, wherein, the cross-sectional area of the first middle leg is larger than the cross-sectional area of the second middle leg.

13. The inductor according to any one of claims 1-12, wherein, at least one of the primary winding and the secondary winding is a film-coated wire.

14. The inductor according to claim 13, wherein, the film-coated wire includes a core layer and a film layer covering the core layer, the core layer includes a metallic material, and the film layer includes an insulating material.

15. The inductor according to any one of claims 1-14, wherein, the magnetic core further includes side legs, and a part of the secondary winding is disposed between the side legs and the first middle leg.

16. A power conversion circuit, wherein, it includes a switching circuit and an inductor according to any one of claims 1-15; the inductor is electrically connected to the switching circuit.

17. A switching power supply, wherein, it includes a control circuit and the power conversion circuit according to claim 16; the control circuit is electrically connected to the power conversion circuit.

18. An electronic device, wherein, it includes: a load and the switching power supply according to claim 17, and the switching power supply is electrically connected to the load.

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