阅读说明：本技术 隔离型功率变换器 (Isolated power converter ) 是由 郜小茹 胡黎强 朱臻 于 2020-06-29 设计创作，主要内容包括：本申请提供一种隔离型功率变换器,包括原边电路、副边电路以及电磁感应器；所述原边电路和所述副边电路藉由变压器元件耦接且相互隔离,所述原边电路具有原边控制器,所述副边电路具有副边控制器；所述电磁感应器设置于印刷电路板上,且具有相互耦合的第一感应元件和第二感应元件；其中所述第一感应元件耦接所述原边控制器,所述第二感应元件耦接所述副边控制器。(The application provides an isolated power converter, which comprises a primary side circuit, a secondary side circuit and an electromagnetic inductor; the primary side circuit and the secondary side circuit are coupled and isolated from each other by a transformer element, the primary side circuit is provided with a primary side controller, and the secondary side circuit is provided with a secondary side controller; the electromagnetic inductor is arranged on the printed circuit board and is provided with a first induction element and a second induction element which are mutually coupled; the first inductive element is coupled to the primary side controller, and the second inductive element is coupled to the secondary side controller.)

1. An isolated power converter, comprising:

the primary side circuit, the secondary side circuit and the electromagnetic inductor;

the primary side circuit and the secondary side circuit are coupled and isolated from each other by a transformer element, the primary side circuit is provided with a primary side controller, and the secondary side circuit is provided with a secondary side controller;

the electromagnetic inductor is arranged on the printed circuit board and is provided with a first induction element and a second induction element which are mutually coupled;

the first inductive element is coupled to the primary side controller, and the second inductive element is coupled to the secondary side controller.

2. The isolated power converter of claim 1, wherein the first and second inductive elements comprise coils, the coils comprising coupling portions.

3. The isolated power converter of claim 2, wherein the coil comprises a wire on the printed circuit board.

4. The isolated power converter of claim 1 wherein said printed circuit board has an insulating layer.

5. The isolated power converter of claim 4, wherein the coupling portions of the first and second inductive elements are disposed on the same side of the insulating layer.

6. The isolated power converter of claim 4, wherein the coupling portions of the first and second inductive elements are disposed on different sides of the insulating layer.

7. The isolated power converter of claim 1, wherein the printed circuit board has a plurality of insulating layers.

8. The isolated power converter of claim 7, wherein the coupling portions of the first and second inductive elements are disposed on one side of any two of the plurality of insulating layers, respectively.

9. The isolated power converter of claim 1, wherein the electromagnetic inductor further comprises at least one shielding element at least partially encasing the coupling portion of at least one of the first and second inductive elements.

10. The isolated power converter of claim 9, wherein said shield element is disposed on said printed circuit board.

Technical Field

The present invention relates generally to integrated circuit and printed circuit board designs, and more particularly to an isolated power converter.

Background

At present, in an isolated power converter circuit, a transformer is generally used to implement electrical isolation of input and output, in order to implement output control and protection functions, it is necessary to sample input or output electrical signals (e.g., current or voltage) and transmit the sampled signals and/or corresponding control signals to an output or input side, and in order to meet the safety requirements of an isolated power converter, an isolation device needs to be arranged in the transmission process of the signals.

The use of discrete isolation devices increases circuit board area and cost, as well as circuit design complexity.

Disclosure of Invention

The invention provides an electromagnetic inductor directly designed on a Printed Circuit Board (PCB) to realize the signal one-way and/or two-way transmission of the input/output side of an isolated power converter and realize the isolation of the input/output side.

In order to solve the technical problem, the invention provides an isolated power converter, which comprises a primary side circuit, a secondary side circuit and an electromagnetic inductor; the primary circuit and the secondary circuit are coupled and isolated from each other by a transformer element, the primary circuit is provided with a primary controller, and the secondary circuit is provided with a secondary controller; the electromagnetic inductor is arranged on the printed circuit board and is provided with a first induction element and a second induction element which are mutually coupled; the first inductive element is coupled to the primary controller, and the second inductive element is coupled to the secondary controller.

In an embodiment of the invention, the first inductive element and the second inductive element comprise coils.

In an embodiment of the invention, the coil comprises a wire in a printed circuit board.

Compared with the prior art, the invention has at least the following advantages: the method and the device realize the one-way or two-way transmission of signals at the input/output side of the isolated power converter, meet the safety requirement of the isolated power converter, have flexible design and can reduce the manufacturing cost.

Drawings

The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this application, illustrate embodiment(s) of the invention and together with the description serve to explain the principle of the invention.

In the drawings:

fig. 1 is a schematic circuit diagram of an isolated power converter according to an embodiment of the present invention.

Fig. 2 is a schematic circuit diagram of an isolated power converter according to another embodiment of the present invention.

Fig. 3 is a schematic plan view of an electromagnetic inductor when the primary and secondary controllers are disposed on the same side of the printed circuit board according to an embodiment of the present invention.

Fig. 4 is a schematic plan view of an electromagnetic inductor when the primary and secondary controllers are disposed on different sides of a printed circuit board according to an embodiment of the present invention.

Fig. 5A is a schematic diagram of a single-turn and same-direction winding of the first conducting wire and the second conducting wire of the electromagnetic inductor when the primary and secondary controllers are disposed on different sides of the printed circuit board according to an embodiment of the present invention.

Fig. 5B is a schematic diagram of the first conducting wire and the second conducting wire of the electromagnetic inductor being single-winding reverse windings when the primary and secondary controllers are disposed on different sides of the printed circuit board according to an embodiment of the present invention.

Fig. 6A is a schematic diagram of a plurality of windings of the primary and secondary controllers of the electromagnetic inductor in the same direction when the primary and secondary controllers are disposed on different sides of the pcb according to an embodiment of the present invention.

Fig. 6B is a schematic diagram of the electromagnetic inductor with the first conducting wire and the second conducting wire wound in opposite directions when the primary and secondary controllers are disposed on different sides of the pcb according to an embodiment of the present invention.

Fig. 7A is a schematic cross-sectional view illustrating an electromagnetic inductor disposed on an upper surface of a single-layer printed circuit board according to an embodiment of the invention.

Fig. 7B is a schematic cross-sectional view illustrating an electromagnetic inductor disposed on a lower surface of a single-layer pcb according to an embodiment of the invention.

Fig. 7C is a schematic cross-sectional view illustrating an electromagnetic inductor disposed on the upper and lower surfaces of a single-layer pcb according to an embodiment of the present invention.

Fig. 8A is a schematic cross-sectional view of an electromagnetic inductor with an isolated power converter disposed on an upper surface of an upper insulating layer of a double-layer pcb according to an embodiment of the invention.

Fig. 8B is a schematic cross-sectional view of an electromagnetic inductor with an isolated power converter disposed on a lower surface of a lower insulating layer of a double-layer pcb according to an embodiment of the invention.

Fig. 8C is a schematic cross-sectional view of an electromagnetic inductor with an isolated power converter disposed between two printed circuit boards according to an embodiment of the invention.

Fig. 8D is a schematic cross-sectional view of an electromagnetic inductor with an isolated power converter disposed on the upper and lower surfaces of an upper insulating layer of a double-layer pcb according to an embodiment of the invention.

Fig. 8E is a schematic cross-sectional view of an electromagnetic inductor with an isolated power converter disposed on the upper surface of the upper insulating layer and the lower surface of the lower insulating layer of the double-layer pcb according to an embodiment of the present invention.

Fig. 9 is a schematic cross-sectional view of an electromagnetic inductor with a shielding layer, in which an isolated power converter according to an embodiment of the present invention is disposed inside a five-layer printed circuit board.

Detailed Description

In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings used in the description of the embodiments will be briefly introduced below. It is obvious that the drawings in the following description are only examples or embodiments of the application, from which the application can also be applied to other similar scenarios without inventive effort for a person skilled in the art. Unless otherwise apparent from the context, or otherwise indicated, like reference numbers in the figures refer to the same structure or operation.

As used in this application and the appended claims, the terms "a," "an," "the," and/or "the" are not intended to be inclusive in the singular, but rather are intended to be inclusive in the plural unless the context clearly dictates otherwise. In general, the terms "comprises" and "comprising" merely indicate that steps and elements are included which are explicitly identified, that the steps and elements do not form an exclusive list, and that a method or apparatus may include other steps or elements.

Spatially relative terms, such as "above … …," "above … …," "above … …," "above," and the like, may be used herein for ease of description to describe one device or feature's spatial relationship to another device 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 a device in the figures is turned over, devices described as "above" or "on" other devices or configurations would then be oriented "below" or "under" the other devices or configurations. Thus, the exemplary term "above … …" can include both an orientation of "above … …" and "below … …". The device may be otherwise variously oriented (rotated 90 degrees or at other orientations) and the spatially relative descriptors used herein interpreted accordingly.

It should be noted that the terms "first", "second", and the like are used to define the components, and are only used for convenience of distinguishing the corresponding components, and the terms have no special meanings unless otherwise stated, and therefore, the scope of protection of the present application is not to be construed as being limited. Further, although the terms used in the present application are selected from publicly known and used terms, some of the terms mentioned in the specification of the present application may be selected by the applicant at his or her discretion, the detailed meanings of which are described in relevant parts of the description herein. Further, it is required that the present application is understood not only by the actual terms used but also by the meaning of each term lying within.

It will be understood that when an element is referred to as being "on," "connected to," "coupled to" or "contacting" another element, it can be directly on, connected or coupled to, or contacting the other element or intervening elements may be present. In contrast, when an element is referred to as being "directly on," "directly connected to," "directly coupled to" or "directly contacting" another element, there are no intervening elements present. Similarly, when a first component is said to be "in electrical contact with" or "electrically coupled to" a second component, there is an electrical path between the first component and the second component that allows current to flow. The electrical path may include capacitors, coupled inductors, and/or other components that allow current to flow even without direct contact between the conductive components.

Embodiments of the present invention describe an isolated power converter. The isolated power converter of various embodiments may include a primary circuit, a secondary circuit, and an electromagnetic inductor. The primary circuit and the secondary circuit are isolated from each other by a transformer element. The primary side circuit has a primary side controller. The secondary side circuit has a secondary side controller. The electromagnetic inductor is arranged on the printed circuit board and is provided with a first induction element and a second induction element which are mutually coupled, wherein the first induction element is coupled with the primary side controller, and the second induction element is coupled with the secondary side controller. Embodiments of the present invention also include some example isolated power converters, including but not limited to synchronous flyback converters, isolated synchronous flyback converters, buck converters, forward converters, half-bridge converters, full-bridge converters, etc., and multi-stage converters formed by cascading the aforementioned plurality of converters.

In one embodiment, the primary side circuit and the secondary side circuit of the isolated power converter have different grounding voltages.

Embodiments of the present invention provide isolation between primary and secondary electrical signals using an electromagnetic inductor disposed on a printed circuit board, the electromagnetic inductor being formed from a metal coil fabricated on the printed circuit board and providing an information path between the primary and secondary electrical circuits.

In one embodiment of the present invention, as shown in fig. 1, a flyback switching converter is taken as an example. IN fig. 1, the flyback switching converter includes a primary circuit 1, a secondary circuit 2, and an electromagnetic inductor 3, where the primary circuit 1 receives an AC input from an AC IN terminal. Diodes D1, D2, D3 and D4 in the primary side circuit 1 form a rectifier bridge circuit, C1 is a filter capacitor, and GND1 is the grounding end of the primary side circuit 1. The absorption circuit formed by the resistor R1, the capacitor C2 and the diode D5 reduces voltage spikes caused by leakage inductance. The primary circuit 1 is coupled to the secondary circuit 2 via a transformer 4 and isolated from each other, and S1 and S2 in the transformer 4 are terminals of the same name as the transformer. The secondary side circuit 2 comprises an output capacitor C3, and the two ends of the C3 are connected with a load. D6 is a rectifier diode. GND2 and GND3 are ground terminals of the secondary circuit 2.

The primary circuit 1 also has a primary controller 11 and the secondary circuit 2 has a secondary controller 21, there being a signal path between the primary and secondary controllers. The secondary controller 21 detects and processes the feedback signal in the secondary circuit 2 to obtain a control signal of the primary power switch operation. In the embodiment shown in fig. 1, the secondary controller 21 may detect the output voltage signal of the secondary circuit through a voltage division sampling circuit composed of resistors R2 and R3, for example, and may select an appropriate voltage for the feedback signal detection terminal FB of the secondary controller by adjusting the resistances of R2 and R3. Since the primary and secondary circuits are isolated and their respective ground voltages are different, the control signal of the secondary controller 21 cannot be directly transmitted to the primary controller 11. In fig. 1, a control signal of the secondary controller 21 is transmitted to the electromagnetic inductor 3 on the printed circuit board through the transmitter 22 disposed in the controller, and is received by the receiver 12 of the primary controller 11 through the isolation and coupling of the electromagnetic inductor 3, and the primary controller 11 controls the operation of the primary switching device M1 based on the control signal. The switching on and off of the switching device M1 enables energy to be transferred from the primary side to the secondary side.

In the isolated power converter of the embodiment of the present invention, the electromagnetic inductor 3 on the printed circuit board is not limited to unidirectional transmission signals, and bidirectional transmission signals can also be implemented. Fig. 2 shows a synchronous flyback power converter of another embodiment, in which the electromagnetic inductor 3 is a bidirectional transmission device. Not only can the primary side controller 11 receive a control signal from the T terminal of the secondary side controller 21 through the R terminal to control the operation of the primary side switching device M1, but also the primary side controller 11 can transmit a control signal to the R terminal of the secondary side controller 21 through the T terminal to control the on or off of the secondary side switching device M2.

In this embodiment, the secondary controller 21 directly samples the output signal, and transmits the output signal to the primary controller 11 through the electromagnetic inductor 3 on the printed circuit board after processing, or transmits the control signal of the primary controller 11 to the secondary controller 21 through the electromagnetic inductor 3 on the printed circuit board, so that the isolated power converter is controlled more accurately and quickly.

In one embodiment of the present invention, the electromagnetic inductor 3 disposed on the printed circuit board comprises two or more inductive elements, such as a coil 13 and a coil 23, as shown in fig. 3-4, wherein the coil 13 is connected to the primary side control chip 11, and the coil 23 is connected to the secondary side control chip 21. The connection may be by way of a pin connection, for example. T1 and T2 are the transmitting ends of the transmitter, and R1 and R2 are the receiving ends of the receiver. The transmitter 22 in the secondary control chip transmits an electrical signal to the coil 23, and a corresponding electrical signal is formed at both ends of the coil 13 by the induced electromagnetic field, and the electrical signal is received by the receiver 12, so that the isolated transmission of the electrical signal is realized.

In a preferred embodiment of the invention, the coils 13 and 23 are made of conductive wires on a printed circuit board and the electromagnetic inductor 3 does not contain a magnetic core. The material of the conductive wire may be copper, for example. In other embodiments, the inductive element may be a structure made of other metal materials, such as an antenna, capable of generating an electromagnetic field.

In some embodiments, as shown in fig. 3, the coupling portions of the coil 13 and the coil 23 are disposed on the same side of the printed circuit board, and the corresponding primary side control chip 11 and secondary side control chip 21 are disposed on the same side of the printed circuit board. And the coupling parts have a spacing a1 between them, a1 may be, for example, 10 mm. The coupling parts of the coil 13 and the coil 23 have a certain distance, so that the effective isolation of electric signals is ensured, the isolated power converter can work safely, and the communication of the primary side and the secondary side is realized.

In some embodiments, as shown in fig. 4, the coupling portions of the coil 13 and the coil 23 are respectively disposed on different sides of the printed circuit board, and the corresponding primary side control chip 11 and the secondary side control chip 21 are disposed on different sides of the printed circuit board. For the printed circuit board substrate commonly used in the industry, the isolation withstand voltage is very high. For example, the breakdown voltage of a single-layer double-sided board with the thickness of 1.5mm and the material of FR-4 can reach 38kV, so that the isolation scheme of the electromagnetic inductor is safe and reliable, the effective isolation of electric signals is ensured, the isolated power converter can work safely, and the communication of the original secondary side is realized.

The shape and relative position of the coil coupling portions in fig. 3 and 4 can be varied reasonably to suit the particular application requirements. For example, fig. 5A is a schematic diagram of the electromagnetic inductor having a single winding and the same direction winding of the first conducting wire and the second conducting wire when the primary and secondary controllers are disposed on different sides of the printed circuit board according to the embodiment of the present invention. Fig. 5B is a schematic diagram of the first conducting wire and the second conducting wire of the electromagnetic inductor being single-winding reverse windings when the primary and secondary controllers are disposed on different sides of the printed circuit board according to the embodiment of the present invention. Fig. 6A is a schematic diagram of a plurality of windings of the primary and secondary controllers of the electromagnetic inductor in the same direction when the primary and secondary controllers are disposed on different sides of the pcb according to an embodiment of the present invention. Fig. 6B is a schematic diagram of the electromagnetic inductor with the first and second wires wound in opposite directions when the primary and secondary controllers are disposed on different sides of the pcb according to the embodiment of the present invention. Specifically, for example, the winding direction of the first conductive wire (or coil) is clockwise, and the winding direction of the second conductive wire (or coil) is counterclockwise. Or the winding direction of the first wire (or coil) is counterclockwise, and the winding direction of the second wire (or coil) is clockwise.

The isolated power converter comprises the electromagnetic inductor manufactured on the printed circuit board, and the area and the shape of the coil can be designed according to requirements, so that signals with different intensities can be transmitted/received, and flexible application is realized.

In the isolated power converter according to the embodiment of the present invention, the printed circuit board on which the electromagnetic inductor is disposed has at least one insulating layer, and the first conductive line (or coil) forming the first inductive element and the second conductive line (or coil) forming the second inductive element may be on the same side of the insulating layer or on different sides of the insulating layer, and the cross-sectional views thereof may be as illustrated in fig. 7A, 7B, and 7C. Specifically, the cross-sectional view is formed, for example, along the section line a-a' of fig. 3, 5A, or 5B. A cross-sectional view may also be formed for fig. 6A or 6B in a similar manner. Fig. 8A-8E and 9 may also be cross-sectional views formed in this manner, and are not described further herein.

Fig. 7A is a schematic cross-sectional view illustrating an electromagnetic inductor disposed on an upper surface of a single-layer printed circuit board according to an embodiment of the invention. Fig. 7B is a schematic cross-sectional view illustrating an electromagnetic inductor disposed on a lower surface of a single-layer pcb according to an embodiment of the invention. Fig. 7C is a schematic cross-sectional view illustrating a first sensing element and a second sensing element of an electromagnetic sensor respectively disposed on an upper surface and a lower surface of a single-layer printed circuit board according to an embodiment of the invention. The printed circuit board is shown with an insulating layer 8, and the inductive elements (e.g., coil 13 and coil 23) are shown as single-turn coils, or as multiple-turn windings; the winding direction of the coils can be the same direction or opposite direction. Different magnetic flux areas can be obtained by setting different winding modes, so that signals with different intensities can be transmitted/received, and flexible application is realized.

The printed circuit board on which the electromagnetic inductor is located in the isolated power converter according to the embodiment of the present invention may also be a printed circuit board having a plurality of insulating layers, and the two winding coils may be on the same side of one of the insulating layers, or may be separated by at least one insulating layer, in other words, disposed on one side of any two insulating layers, respectively, and their cross-sectional views may be as illustrated in fig. 8A to 8E.

Fig. 8A is a schematic cross-sectional view of an electromagnetic inductor disposed on the upper surface of an upper insulating layer 81, wherein the electromagnetic inductor forms a first conductive line of a first inductive element and a second conductive line of a second inductive element in an isolated power converter according to an embodiment of the present invention. The coil wiring mode of the first lead and the second lead can be single-coil winding or multi-coil winding.

Fig. 8B is a schematic cross-sectional view of the electromagnetic inductor disposed on the lower surface of the lower insulating layer 82, wherein the electromagnetic inductor forms a first conductive line of the first inductive element and a second conductive line of the second inductive element in the isolated power converter according to the embodiment of the present invention. The coil wiring mode of the first lead and the second lead can be single-coil winding or multi-coil winding.

Fig. 8C is a schematic cross-sectional view of the electromagnetic inductor disposed between the upper insulating layer 81 and the lower insulating layer 82 on the printed circuit board, wherein the electromagnetic inductor forms a first conductive line of the first inductive element and a second conductive line of the second inductive element in the isolated power converter according to the embodiment of the present invention. The coil wiring mode of the first lead and the second lead can be single-coil winding or multi-coil winding.

Fig. 8D is a schematic cross-sectional view of an electromagnetic inductor in which the electromagnetic inductor forms a first conductive line of a first inductive element and a second conductive line of a second inductive element, and the first conductive line is disposed on the upper surface of the upper insulating layer 81 and the second conductive line is disposed on the lower surface of the upper insulating layer 81 in the isolated power converter according to the embodiment of the present invention. Alternatively, the first conductive line is disposed on the lower surface of the upper insulating layer 81, and the second conductive line is disposed on the upper surface of the upper insulating layer 81. The coil wiring mode of the first lead and the second lead can be single-coil winding or multi-coil winding.

Fig. 8E is a schematic cross-sectional view of the electromagnetic inductor in which the electromagnetic inductor forms a first conductive line of the first inductive element and a second conductive line of the second inductive element, and the first conductive line is disposed on the upper surface of the upper insulating layer 81 and the second conductive line is disposed on the lower surface of the lower insulating layer 82 in the isolated power converter according to the embodiment of the present invention. Alternatively, the first conductive line is disposed on the lower surface of the lower insulating layer 82, and the second conductive line is disposed on the upper surface of the upper insulating layer 81. The coil wiring mode of the first lead and the second lead can be single-coil winding or multi-coil winding.

In some embodiments, the isolated power converter of the present application further comprises a shielding element at least partially encasing the inductive element of the electromagnetic inductor.

Fig. 9 is a schematic cross-sectional view of an electromagnetic inductor of an isolated power converter implemented as an electromagnetic inductor inside a five-layer printed circuit board with a shielding layer according to an embodiment of the present invention. As illustrated in FIG. 9, the insulating layers of the five-layer PCB are respectively 101-105. The electromagnetic inductor is composed of a first conductive line 106 forming a first inductive element and a second conductive line 107 forming a second inductive element. Shielding layers 108 and 109 are also included. The material of the shielding layer may be a metal material, and the specific material may be selected according to actual requirements, such as copper or aluminum. The shielding layers 108 and 109 at least partially cover the coupling portions of the inductive elements 106 and 107, and the distribution positions of the shielding layers can be adjusted as needed, for example, the shielding layers are respectively arranged on the upper surface of the uppermost layer and the lower surface of the lowermost layer of the printed circuit board.

The electromagnetic inductor behind the setting shielding layer shields the interference of external electromagnetic signal more easily to make and have better signal transmission effect between first wire (being coil 1) and the second wire (being coil 2).

In some embodiments, the electromagnetic inductor may also be fabricated on a separate printed circuit board, mounted on the main printed circuit board in the form of a card. The interposer may be a single layer or a multilayer board.

The isolated power converter utilizes the metal wire on the printed circuit board to design the electromagnetic inductor to transmit the isolated electric signal, has flexible and convenient specific implementation mode, can reduce the manufacturing cost, and has high isolation withstand voltage, safety and reliability.

Having thus described the basic concept, it will be apparent to those skilled in the art that the foregoing disclosure of the embodiments of the invention is provided merely as an example and is not intended to limit the present application. Various modifications, improvements and adaptations to the present application may occur to those skilled in the art, although not explicitly described herein. Such modifications, improvements and adaptations are proposed in the present application and thus fall within the spirit and scope of the exemplary embodiments of the present application.

Also, this application uses specific language to describe embodiments of the application. Reference throughout this specification to "one embodiment," "an embodiment," and/or "some embodiments" means that a particular feature, structure, or characteristic described in connection with at least one embodiment of the present application is included in at least one embodiment of the present application. Therefore, it is emphasized and should be appreciated that two or more references to "an embodiment" or "one embodiment" or "an alternative embodiment" in various places throughout this specification are not necessarily all referring to the same embodiment. Furthermore, some features, structures, or characteristics of one or more embodiments of the present application may be combined as appropriate.

Although the present application has been described with reference to the present specific embodiments, it will be recognized by those skilled in the art that the foregoing embodiments are merely illustrative of the present application and that various changes and substitutions of equivalents may be made without departing from the spirit of the application, and therefore, it is intended that all changes and modifications to the above-described embodiments that come within the spirit of the application fall within the scope of the claims of the application.