CN218730329U

CN218730329U - Transformer and switching power supply circuit

Info

Publication number: CN218730329U
Application number: CN202222747243.4U
Authority: CN
Inventors: 邓波; 侯永军; 杨小华
Original assignee: Shenzhen ICM Microelectronics Co Ltd
Current assignee: Shenzhen Chuangxin Microelectronics Co ltd
Priority date: 2022-10-18
Filing date: 2022-10-18
Publication date: 2023-03-24
Anticipated expiration: 2032-10-18

Abstract

The utility model discloses a transformer and a switch power supply circuit, wherein the transformer comprises a framework winding slot, a shielding winding, a primary winding, an auxiliary winding and a secondary winding, wherein a magnetic core is arranged inside the framework winding slot; the shielding winding, the primary winding, the auxiliary winding and the secondary winding are sequentially wound on the framework winding slot from inside to outside. According to the technical scheme, the shielding winding is arranged on the innermost layer, the primary winding is arranged on the periphery of the shielding winding, the auxiliary winding is arranged on the periphery of the primary winding, and the secondary winding is arranged on the outermost layer, so that the coupling capacitance between the primary winding and the secondary winding can be reduced, the common-mode current between the primary winding and the secondary winding is further reduced, and the EMI (electro-magnetic interference) conduction performance of the transformer is improved.

Description

Transformer and switching power supply circuit

Technical Field

The utility model relates to an electronic information technical field especially relates to a transformer and switching power supply circuit.

Background

The switching Power Supply is a Switching Mode Power Supply (SMPS), also called switching Power Supply or switching converter, and is a high-frequency Power conversion device, which is a kind of Power Supply. The function is to convert a level voltage into a voltage or current required by the user terminal through different types of architectures.

The transformer in the existing switching power supply circuit generally comprises a primary winding, a secondary winding and an auxiliary winding, and is wound by adopting a sandwich winding method, for example, the primary winding clamps the secondary winding or the secondary winding clamps the primary winding, so that the effective coupling area between the primary winding and the secondary winding of the transformer can be increased, the leakage inductance of the transformer is reduced, and the overall efficiency of the power supply is improved. However, since the effective coupling area between the primary winding and the secondary winding is increased, the coupling capacitance between the primary winding and the secondary winding is increased, and the EMI (Electromagnetic Interference) conduction performance of the transformer is deteriorated. In the prior art, in order to solve the problem of poor performance of conducting EMI of a transformer, the electromagnetic interference is usually reduced by adding a Y capacitor in a switching power supply circuit, but the increase of the Y capacitor occupies the space of a PCB board or a complete machine, the design cost is also increased, and meanwhile, the Y capacitor may cause leakage current to cause noise to a system. Therefore, a transformer capable of improving the performance of conducting EMI is needed.

SUMMERY OF THE UTILITY MODEL

An embodiment of the utility model provides a transformer and switching power supply circuit to solve the current relatively poor problem of transformer conduction EMI performance.

A transformer comprises a framework winding slot, a shielding winding, a primary winding, an auxiliary winding and a secondary winding, wherein a magnetic core is arranged in the framework winding slot; the shielding winding, the primary winding, the auxiliary winding and the secondary winding are sequentially wound on the framework winding slot from inside to outside.

Furthermore, the shielding windings are uniformly distributed on the framework winding slots.

Further, the number of layers of the shielding winding is 1.

Further, the bobbin winding slot comprises a primary side and a secondary side, the primary side is provided with a first pin and a second pin, and the secondary side is provided with a third pin and a fourth pin;

the starting end and the ending end of the primary winding are respectively connected to a first pin and a second pin of the framework winding slot;

and the starting end and the ending end of the secondary winding are respectively connected to the third pin and the fourth pin of the framework winding slot.

Further, the shielding winding comprises at least two first winding wires;

at least two first windings wind around on skeleton wire winding groove, every the initiating terminal of first winding links to each other with the fifth pin on the skeleton wire winding groove, every the end of first winding is unsettled.

Further, the number of layers of the auxiliary winding is 1.

Further, the auxiliary winding includes at least two second windings; and at least two second windings are wound on the framework winding groove, the starting end of each second winding is connected with a sixth pin on the framework winding groove, and the finishing end of each second winding is connected with a seventh pin on the framework winding groove.

Further, the winding directions of the shielding winding, the primary winding, the auxiliary winding and the secondary winding are the same.

Furthermore, insulating layers are arranged outside the shielding winding, the primary winding, the auxiliary winding and the secondary winding.

A switching power supply circuit comprises the transformer.

According to the transformer and the switching power supply circuit, the shielding winding is arranged on the innermost layer, the primary winding is arranged on the periphery of the shielding winding, the auxiliary winding is arranged on the periphery of the primary winding, and the secondary winding is arranged on the outermost layer, so that the coupling capacitance between the primary winding and the secondary winding can be reduced, the common-mode current between the primary winding and the secondary winding is further reduced, and the conduction EMI performance of the transformer is improved.

Drawings

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

Fig. 1 is a sectional view of a transformer according to an embodiment of the present invention.

In the figure: 10. a framework winding slot; 11. a primary side; 12. a secondary side; 20. a shield winding; 30. a primary winding; 40. an auxiliary winding; 50. a secondary winding.

Detailed Description

The technical solutions in the embodiments of the present invention will be described clearly and completely with reference to the accompanying drawings in the embodiments of the present invention, and it is obvious that the described embodiments are some, not all, of the embodiments of the present invention. Based on the embodiments in the present invention, all other embodiments obtained by a person skilled in the art without creative efforts belong to the protection scope of the present invention.

It is to be understood that the present invention may be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art. In the drawings, the size and relative sizes of layers and regions may be exaggerated throughout the same reference numerals to indicate same elements for clarity.

It will be understood that when an element or layer is referred to as being "on," "adjacent to," "connected to," or "coupled to" another element or layer, it can be directly on, adjacent to, connected to, or coupled to the other element or layer, or intervening elements or layers may be present. In contrast, when an element is referred to as being "directly on," "directly adjacent," "directly connected to," or "directly coupled to" other elements or layers, there are no intervening elements or layers present. It will be understood that, although the terms first, second, third, etc. may be used to describe various elements, components, regions, layers and/or sections, these elements, components, regions, layers and/or sections should not be limited by these terms. These terms are only used to distinguish one element, component, region, layer or section from another element, component, region, layer or section. Thus, a first element, component, region, layer or section discussed below could be termed a second element, component, region, layer or section without departing from the teachings of the present invention.

Spatial relationship terms such as "under 823030," "under 8230; below," "under 8230," "under," "over," and the like may be used herein for convenience of description to describe the relationship of one element or feature to another element or feature as illustrated in the figures. It will be understood that the spatially relative terms are intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the figures. For example, if the device in the figures is turned over, elements or features described as "below" or "beneath" other elements or features would then be oriented "above" the other elements or features. Thus, the exemplary terms "at 8230, below" and "at 8230, below" may include both an upper and a lower orientation. The device may be otherwise oriented (rotated 90 degrees or at other orientations) and the spatial descriptors used herein interpreted accordingly.

The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. As used herein, the singular forms "a", "an" and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms "comprises" and/or "comprising," when used in this specification, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof. As used herein, the term "and/or" includes any and all combinations of the associated listed items.

In order to provide a thorough understanding of the present invention, detailed structures and steps will be provided in the following description so as to explain the technical solution provided by the present invention. The preferred embodiments of the present invention are described in detail below, however, other embodiments of the present invention are possible in addition to these detailed descriptions.

The present embodiment provides a transformer, as shown in fig. 1, including a bobbin winding slot 10 with a magnetic core inside, a shielding winding 20, a primary winding 30, an auxiliary winding 40, and a secondary winding 50; the shielding winding 20, the primary winding 30, the auxiliary winding 40 and the secondary winding 50 are sequentially wound on the bobbin winding slot 10 from inside to outside.

As an example, the transformer includes a bobbin winding slot 10 and a magnetic core. The core is mounted in the bobbin winding slot 10. The core is generally used to increase the magnetic induction of the electromagnet.

In the present embodiment, by disposing the shielding winding 20 at the innermost layer to shield the radiation interference caused by the interference signal overflowing to the space, disposing the primary winding 30 at the periphery of the shielding winding 20, disposing the auxiliary winding 40 at the periphery of the primary winding 30, and disposing the secondary winding 50 at the outermost layer, two common mode currents, positive and negative, can be generated due to the coupling capacitance between the primary winding 30 and the secondary winding 50, and by disposing the auxiliary winding 40 between the primary winding 30 and the secondary winding 50, at least part of the positive and negative common mode currents can be cancelled, thereby reducing the common mode current between the primary winding 30 and the secondary winding 50, and thus improving the conducted EMI performance of the transformer.

In one embodiment, the shield windings 20 are uniformly arranged on the bobbin winding slots 10.

In the present embodiment, the shielding windings 20 are uniformly arranged on the bobbin winding slots 10, so as to ensure that the current transmitted on the shielding windings 20 is more uniform, prevent the generation of unnecessary common mode current, and thus improve the EMI conduction performance of the transformer.

In one embodiment, the number of layers of the shield winding 20 is 1.

In the present embodiment, the number of layers of the shielding winding 20 is configured to be 1 layer, so as to reduce the number of turns of the winding in the shielding winding 20, to reduce the coupling capacitance between the primary winding 30 and the secondary winding 50, and to reduce the common mode current between the primary winding 30 and the secondary winding 50, thereby improving the conducted EMI performance of the transformer.

In one embodiment, the bobbin winding slot 10 includes a primary side 11 and a secondary side 12, the primary side 11 is provided with a first PIN1 and a second PIN2, and the secondary side 12 is provided with a third PIN3 and a fourth PIN4; the starting end and the ending end of the primary winding 30 are respectively connected to a first PIN PIN1 and a second PIN PIN2 of the bobbin winding slot 10; the starting end and the ending end of the secondary winding 50 are respectively connected to the third PIN PIN3 and the fourth PIN PIN4 of the bobbin winding slot 10.

As an example, the bobbin winding slot 10 is provided at both sides thereof with a primary side 11 and a secondary side 12, and the primary side 11 is provided with a first PIN1 and a PIN for connecting the primary winding 30. The secondary side 12 is provided with a third PIN3 and a fourth PIN4 for connection to the secondary winding 50.

As an example, the starting end and the ending end of the primary winding 30 are respectively connected to the first PIN1 and the second PIN2 of the bobbin winding slot 10. In this example, specific parameters of the primary winding 30, such as winding material, number of turns, and number of layers, may be set according to transformer parameters, for example, the number of layers of the primary winding 30 may be three.

As an example, the starting end and the ending end of the secondary winding 50 are respectively connected to the third PIN3 and the fourth PIN4 of the bobbin winding slot 10. In this example, the specific parameters of the secondary winding 50, such as the winding material, the number of turns, and the number of layers, may be set according to the transformer parameters, for example, the number of layers of the secondary winding 50 may be one. Further, the secondary winding 50 may be wound by a single wire, or may be wound by multiple wires, for example, by a double wire winding, which depends on the number of output groups required, for example, when only one output group is required, the secondary winding may be wound by a single wire, and the start end and the end of the single wire serve as a group of output ports; when two sets of outputs are required, a double-wire parallel winding structure can be adopted, wherein the starting end and the ending end of one winding in the double wires are used as one set of output ports, and the starting end and the output end of the other winding are used as the other set of output ports.

In one embodiment, the shield winding 20 includes at least two first windings; at least two first windings are wound on the framework winding groove 10, the starting end of each first winding is connected with a fifth PIN PIN5 on the framework winding groove 10, and the ending end of each first winding is suspended.

Wherein floating means that no electrical connection is made. In this example, the end of each first winding may be wired to the NC pin to ensure stability and reliability of the transformer. Illustratively, the NC pin may be disposed on the primary side 11 of the bobbin winding slot 10.

As an example, at least two first windings are wound on the bobbin winding slot 10, the start end of each first winding is connected to the fifth PIN5 on the bobbin winding slot 10, and the end of each first winding is suspended. In this example, at least two first windings are wound around the bobbin winding slot 10, and the start end of each first winding is connected to the fifth PIN5 on the bobbin winding slot 10, that is, the shielding winding 20 is wound around the bobbin winding slot 10 in a parallel winding manner, so that the number of layers of the shielding winding 20 is 1, and the number of turns of the first winding in the shielding winding 20 is reduced, thereby reducing the coupling capacitance between the primary winding 30 and the secondary winding 50, further reducing the common-mode current between the primary winding 30 and the secondary winding 50, and further improving the conducted EMI performance of the transformer.

In one embodiment, the number of layers of the auxiliary winding 40 is 1.

In the present embodiment, the number of layers of the auxiliary winding 40 is configured to be 1 layer, so as to reduce the number of turns of the winding in the auxiliary winding 40, to reduce the coupling capacitance between the primary winding 30 and the secondary winding 50, and to reduce the common mode current between the primary winding 30 and the secondary winding 50, thereby improving the conducted EMI performance of the transformer.

In one embodiment, the auxiliary winding 40 includes at least two second windings; the at least two second windings are wound on the bobbin winding grooves 10, the starting end of each second winding is connected with a sixth PIN PIN6 on the bobbin winding grooves 10, and the finishing end of each second winding is connected with a seventh PIN PIN7 on the bobbin winding grooves 10.

As an example, at least two second windings are wound on the bobbin winding slot 10, the start end of each second winding is connected to the sixth PIN6 on the bobbin winding slot 10, and the end of each second winding is connected to the seventh PIN7 on the bobbin winding slot 10. In this example, at least two second windings are wound on the bobbin winding slot 10, the start end of each second winding is connected to the sixth PIN6 on the bobbin winding slot 10, and the end of each second winding is connected to the seventh PIN7 on the bobbin winding slot 10, that is, the auxiliary winding 40 is wound on the bobbin winding slot 10 in a parallel winding manner, so that the number of layers of the auxiliary winding 40 is 1, and the number of turns of the second winding in the auxiliary winding 40 is reduced, so that the coupling capacitance between the primary winding 30 and the secondary winding 50 is reduced, the common mode current between the primary winding 30 and the secondary winding 50 is reduced, and the EMI conduction performance of the transformer is improved.

In one embodiment, the winding directions of the shield winding 20, the primary winding 30, the auxiliary winding 40 and the secondary winding 50 are the same.

In this embodiment, the winding directions of the shielding winding 20, the primary winding 30, the auxiliary winding 40 and the secondary winding 50 are the same, so that the complexity of the transformer production process is reduced, and the winding efficiency of the shielding winding 20, the primary winding 30, the auxiliary winding 40 and the secondary winding 50 is improved.

In one embodiment, the shielding winding 20, the primary winding 30, the auxiliary winding 40, and the secondary winding 50 are provided with an insulating layer on the outside.

Wherein the insulating layer includes, but is not limited to, a polyamine film, an insulating lacquer coating, or a fiberglass layer.

In this embodiment, the insulating layers are disposed outside the shielding winding 20, the primary winding 30, the auxiliary winding 40, and the secondary winding 50, so that the shielding winding 20, the primary winding 30, the auxiliary winding 40, and the secondary winding 50 can bear a high ac voltage, thereby improving safety.

The embodiment provides a switching power supply circuit, which comprises the transformer.

In this embodiment, since the switching power supply circuit includes the transformer in the above embodiments, the transformer has a better EMI conduction performance, so that it is not necessary to add a Y capacitor in the switching power supply circuit to reduce electromagnetic interference, reduce design cost, avoid leakage current caused by the Y capacitor, and improve the overall performance of the switching power supply circuit.

The above-mentioned embodiments are only used for illustrating the technical solution of the present invention, and not for limiting the same; although the present invention has been described in detail with reference to the foregoing embodiments, it should be understood by those skilled in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some technical features may be equivalently replaced; such modifications and substitutions do not substantially depart from the spirit and scope of the embodiments of the present invention, and are intended to be included within the scope of the present invention.

Claims

1. A transformer is characterized by comprising a framework winding slot, a shielding winding, a primary winding, an auxiliary winding and a secondary winding, wherein a magnetic core is arranged in the framework winding slot; the shielding winding, the primary winding, the auxiliary winding and the secondary winding are sequentially wound on the framework winding slot from inside to outside.

2. The transformer of claim 1, wherein the shield windings are evenly arranged on the bobbin winding slots.

3. The transformer of claim 2, wherein the number of layers of the shield winding is 1.

4. The transformer of claim 1, wherein the bobbin winding slot comprises a primary side and a secondary side, the primary side being provided with a first pin and a second pin, the secondary side being provided with a third pin and a fourth pin;

the starting end and the ending end of the primary winding are respectively connected to the first pin and the second pin of the framework winding slot;

5. The transformer of claim 4, wherein the shield winding comprises at least two first windings;

6. The transformer of claim 1, wherein the number of layers of the auxiliary winding is 1.

7. The transformer of claim 6, wherein the auxiliary winding comprises at least two second windings; and at least two second windings are wound on the framework winding groove, the starting end of each second winding is connected with a sixth pin on the framework winding groove, and the finishing end of each second winding is connected with a seventh pin on the framework winding groove.

8. The transformer of claim 1, wherein the shield winding, the primary winding, the auxiliary winding, and the secondary winding are wound in the same direction.

9. The transformer of claim 1, wherein the shield winding, the primary winding, the auxiliary winding, and the secondary winding are provided with an insulating layer on the outside.

10. A switched-mode power supply circuit, characterized in that it comprises a transformer according to any one of claims 1-9.