WO2023279322A1

WO2023279322A1 - Communication transformer and corresponding electronic device

Info

Publication number: WO2023279322A1
Application number: PCT/CN2021/105177
Authority: WO
Inventors: Yingkun XU; Huan SHI; Wei Liu; Jincheng Li
Original assignee: Abb Schweiz Ag
Priority date: 2021-07-08
Filing date: 2021-07-08
Publication date: 2023-01-12
Also published as: CN117063253A

Abstract

Embodiments of the present disclosure provide a communication transformer and an electronic device comprising the same. The communication transformer comprises: a primary winding comprising a first set of sub-windings arranged in layers and connected in series between a high-side input terminal and a low-side input terminal; a secondary winding spaced apart from the primary winding and comprising a second set of sub-windings arranged in layers and connected in series between a high-side output terminal and a low-side output terminal; a first shield layer arranged between the primary winding and the secondary winding and electrically connected to the low-side input terminal; and a second shield layer arranged between the first shield layer and the secondary winding and electrically connected to one of the second set of sub-windings nearest to the primary winding, the second shield layer being at a distance from the first shield layer. According to embodiments of the present disclosure, with the first shield layer and the second shield layer, the anti-interference ability of the communication transformer will be significantly improved.

Description

COMMUNICATION TRANSFORMER AND CORRESPONDING ELECTRONIC DEVICE

FIELD

Example embodiments of the present disclosure generally relate to the field of communication technology, and more specifically, to a communication transformer and an electronic device comprising the same.

BACKGROUND

Communication transformers are widely used in various electronic devices, such as a distributed control system (DCS) , a network communication device, a data communication device, a photoelectric device, and a voice device, etc. For example, in some DCS, there is a serial interface between the controller and the input/out (I/O) module to achieve the communication therebetween. The serial interface is an isolated half-duplex communication link and the isolation is achieved through using a communication transformer having two coupled windings for transmitting signals and another communication transformer having two coupled windings for receiving signals. The communication transformers operate in a resonant mode.

However, the communication transformer, especially the one for transmitting the signals, typically has a poor anti-interference ability against electromagnetic interference (EMI) . Specifically, since there are parasitic capacitances between a primary winding and a secondary winding of the communication transformer, common mode interference in the communication transformer will become differential mode interference, which will affect the quality of the signal transmitted by the communication transformer.

Thus, there is a need for a solution for reducing the effect of the EMI on the signal transmitted by the communication transformer.

SUMMARY

In view of the foregoing problems, example embodiments of the present disclosure propose a communication transformer and an electronic device comprising the same.

In a first aspect, example embodiments of the present disclosure provide a communication transformer comprising: a primary winding comprising a first set of sub-windings arranged in layers and connected in series between a high-side input terminal and a low-side input terminal; a secondary winding spaced apart from the primary winding and comprising a second set of sub-windings arranged in layers and connected in series between a high-side output terminal and a low-side output terminal; a first shield layer arranged between the primary winding and the secondary winding and electrically connected to the low-side input terminal; and a second shield layer arranged between the first shield layer and the secondary winding and electrically connected to one of the second set of sub-windings nearest to the primary winding, the second shield layer being at a distance from the first shield layer.

According to embodiments of the present disclosure, with the first shield layer and the second shield layer, the anti-interference ability of the communication transformer will be significantly improved.

In some embodiments, the first set of sub-windings comprise a first sub-winding, a second sub-winding, a third sub-winding, and a fourth sub-winding, the first sub-winding is one of the first set of sub-windings farthest away from the secondary winding, and the fourth sub-winding is one of the first set of sub-windings nearest to the secondary winding, the second set of sub-windings comprise a fifth sub-winding, a sixth sub-winding, a seventh sub-winding, and an eighth sub-winding, and the fifth sub-winding is one of the second set of sub-windings nearest to the primary winding, and the eighth sub-winding is one of the second set of sub-windings farthest away from the primary winding.

In some embodiments, the high-side input terminal is electrically connected to an outer tap of the second sub-winding, an inner tap of the second sub-winding is electrically connected to an inner tap of the first sub-winding, an outer tap of the first sub-winding is electrically connected to an outer tap of the fourth sub-winding, an inner tap of the fourth sub-winding is electrically connected to an inner tap of the third sub-winding, and an outer tap of the third sub-winding is electrically connected to the low-side input terminal.

In some embodiments, the high-side output terminal is electrically connected to an outer tap of the sixth sub-winding, an inner tap of the sixth sub-winding is electrically connected to an inner tap of the fifth sub-winding, an outer tap of the fifth sub-winding is electrically connected to an outer tap of the eighth sub-winding, an inner tap of the eighth sub-winding is electrically connected to an inner tap of the seventh sub-winding, and an outer tap of the seventh sub-winding is electrically connected to the low-side output terminal.

In some embodiments, the high-side input terminal is electrically connected to an outer tap of the first sub-winding, an inner tap of the first sub-winding is electrically connected to an inner tap of the second sub-winding, an outer tap of the second sub-winding is electrically connected to an outer tap of the third sub-winding, an inner tap of the third sub-winding is electrically connected to an inner tap of the fourth sub-winding, and an outer tap of the fourth sub-winding is electrically connected to the low-side input terminal.

In some embodiments, the high-side output terminal is electrically connected to an outer tap of the eighth sub-winding, an inner tap of the eighth sub-winding is electrically connected to an inner tap of the seventh sub-winding, an outer tap of the seventh sub-winding is electrically connected to an outer tap of the sixth sub-winding, an inner tap of the sixth sub-winding is electrically connected to an inner tap of the fifth sub-winding, and an outer tap of the fifth sub-winding is electrically connected to the low-side output terminal.

In some embodiments, the first set of sub-windings further comprise one or more additional sub-windings arranged between the first sub-winding and the fourth sub-winding.

In some embodiments, the second set of sub-windings further comprise one or more additional sub-windings arranged between the fifth sub-winding and the eighth sub-winding.

In some embodiments, each of the first shield layer and the second shield layer is formed from a metal sheet or a metal line.

In a second aspect, example embodiments of the present disclosure provide an electronic device comprising: a printed circuit board; and a communication transformer according to the first aspect of the present disclosure arranged on the printed circuit board.

DESCRIPTION OF DRAWINGS

Drawings described herein are provided to further explain the present disclosure and constitute a part of the present disclosure. The example embodiments of the disclosure and the explanation thereof are used to explain the present disclosure, rather than to limit the present disclosure improperly.

Fig. 1 illustrates a schematic circuit diagram of a signal transmitting circuit in accordance with an embodiment of the present disclosure;

Fig. 2 illustrates a schematic structural view of a conventional communication transformer;

Fig. 3 illustrates a schematic structural view of a communication transformer in accordance with an embodiment of the present disclosure;

Fig. 4 illustrates a schematic operation principle of the signal transmitting circuit as shown in Fig. 1 when using the communication transformer as shown in Fig. 3;

Fig. 5 illustrates a schematic structural view of a communication transformer in accordance with another embodiment of the present disclosure;

Fig. 6 illustrates a schematic structural view of a communication transformer in accordance with yet another embodiment of the present disclosure; and

Fig. 7 illustrates a schematic operation principle of the signal transmitting circuit as shown in Fig. 1 when using the communication transformer as shown in Fig. 6.

Throughout the drawings, the same or similar reference symbols are used to indicate the same or similar elements.

DETAILED DESCRIPTION OF EMBODIEMTNS

Principles of the present disclosure will now be described with reference to several example embodiments shown in the drawings. Though example embodiments of the present disclosure are illustrated in the drawings, it is to be understood that the embodiments are described only to facilitate those skilled in the art in better understanding and thereby achieving the present disclosure, rather than to limit the scope of the disclosure in any manner.

The term “comprises” or “includes” and its variants are to be read as open terms that mean “includes, but is not limited to. ” The term “or” is to be read as “and/or” unless the context clearly indicates otherwise. The term “based on” is to be read as “based at least in part on. ” The term “being operable to” is to mean a function, an action, a motion or a state can be achieved by an operation induced by a user or an external mechanism. The term “one embodiment” and “an embodiment” are to be read as “at least one embodiment. ” The term “another embodiment” is to be read as “at least one other embodiment. ” The terms “first, ” “second, ” and the like may refer to different or same objects. Other definitions, explicit and implicit, may be included below. A definition of a term is consistent throughout the description unless the context clearly indicates otherwise.

As discussed above, the conventional communication transformer for transmitting signals has a poor anti-interference ability against electromagnetic interference (EMI) . Fig. 1 illustrates a schematic circuit diagram of a signal transmitting circuit in accordance with an embodiment of the present disclosure. As shown in Fig. 1, the signal transmitting circuit 200 includes a communication transformer 100 having a primary winding 101 and a secondary winding 102. The primary winding 101 has a high-side input terminal pin5 and a low-side input terminal pin6. An input capacitor C1 is connected between the high-side input terminal pin5 and the low-side input terminal pin6. The secondary winding 102 has a high-side output terminal pin3 and a low-side output terminal pin4. A Schottky diode SBD and a resistor R1 are connected in series between the high-side output terminal pin3 and a node N1. The node N1 is connected to a base of a bipolar NPN transistor T1. A collector of the transistor T1 is connected to ground EM. A capacitor C2 is connected between the node N1 and the ground EM. A thermistor R2 is connected between the node N1 and the ground EM. With the above arrangement, the signals may be transmitted by the signal transmitting circuit 200.

Fig. 2 illustrates a schematic structural view of a conventional communication transformer. As shown in Fig. 2, in the communication transformer 100, the primary winding 101 includes a first sub-winding L1, a second sub-winding L2, a third sub-winding L3, and a fourth sub-winding L4 arranged in layers and connected in series between the high-side input terminal pin5 and the low-side input terminal pin6. The secondary winding 102 includes a fifth sub-winding L5, a sixth sub-winding L6, a seventh sub-winding L7, and an eighth sub-winding L8 arranged in layers and connected in series between the high-side output terminal pin3 and the low-side output terminal pin4.

As shown in Fig. 2, the high-side input terminal pin5 is electrically connected to an outer tap of the second sub-winding L2. An inner tap of the second sub-winding L2 is electrically connected to an inner tap of the first sub-winding L1. An outer tap of the first sub-winding L1 is electrically connected to an outer tap of the fourth sub-winding L4. An inner tap of the fourth sub-winding L4 is electrically connected to an inner tap of the third sub-winding L3. An outer tap of the third sub-winding L3 is electrically connected to the low-side input terminal pin6.

As shown in Fig. 2, the high-side output terminal pin3 is electrically connected to an outer tap of the sixth sub-winding L6. An inner tap of the sixth sub-winding L6 is electrically connected to an inner tap of the fifth sub-winding L5. An outer tap of the fifth sub-winding L5 is electrically connected to an outer tap of the eighth sub-winding L8. An inner tap of the eighth sub-winding L8 is electrically connected to an inner tap of the seventh sub-winding L7. An outer tap of the seventh sub-winding L7 is electrically connected to the low-side output terminal pin4.

In the communication transformer 100, parasitic capacitances may exist between the primary winding 101 and the secondary winding 102. For example, as shown in Fig. 1, a parasitic capacitance C ₅₃ exists between the high-side input terminal pin5 and the high-side output terminal pin3, a parasitic capacitance C ₅₄ is exists between the high-side input terminal pin5 and the low-side output terminal pin4, a parasitic capacitance C ₆₃ exists between the low-side input terminal pin6 and the high-side output terminal pin3, and a parasitic capacitance C ₆₄ exists between the low-side input terminal pin6 and the low-side output terminal pin4.

In the signal transmitting circuit 200, there may be two kinds of interferences, one is an electrical fast transient (EFT) interference, and the other one is a conducted RF interference. The EFT interference may be transmitted from the low-side input terminal pin6 to the high-side output terminal pin3 and the low-side output terminal pin4 via the parasitic capacitance C ₆₃ and the parasitic capacitance C ₆₄, respectively. The conducted RF interference may be transmitted from the high-side input terminal pin5 to the high-side output terminal pin3 and the low-side output terminal pin4 via the parasitic capacitance C ₅₃ and the parasitic capacitance C ₅₄, respectively. The EFT interference transmitted from the low-side input terminal pin6 to the high-side output terminal pin3 and the conducted RF interference transmitted from the high-side input terminal pin5 to the high-side output terminal pin3 will result in a common current I _common in the signal transmitting circuit 200. The common current I _common will affect the quality of the signals transmitted by the signal transmitting circuit 200 and may cause a wrong ON/OFF operation of the transistor T1.

As shown in Fig. 1, to inhibit the interferences in the signal transmitting circuit 200, two Y-capacitors CY are connected in series between the low-side input terminal pin6 and the ground EM. The Y-capacitors CY may reduce the interferences in the signal transmitting circuit 200 to some extent. However, the cost of the Y-capacitors CY is relatively high, which will increase the overall cost of the signal transmitting circuit 200. Moreover, as shown in Fig. 1, a coupling clamp C3, a resistor R3 and a noise source NS are connected in series between the low-side input terminal pin6 and the ground EM so as to imitate the interferences in the signal transmitting circuit 200.

According to embodiments of the present disclosure, in order to prevent the interferences existing in the signal transmitting circuit 200 from affecting the quality of the signals transmitted by the signal transmitting circuit 200, a pair of shield layers are provided in the communication transformer 100 and the line connection manner of the communication transformer 100 is changed. The above idea may be implemented in various manners, as will be described in detail in the following paragraphs.

Hereinafter, the principles of the present disclosure will be described in detail with reference to Figs. 3-7. Referring to Fig. 3 first, Fig. 3 illustrates a schematic structural view of a communication transformer in accordance with an embodiment of the present disclosure. As shown in Fig. 3, the communication transformer 100 generally includes a primary winding 101, a secondary winding 102, a first shield layer 103, and a second shield layer 104. The primary winding 101 includes a first set of sub-windings arranged in layers and connected in series between the high-side input terminal pin5 and the low-side input terminal pin6. The secondary winding 102 is spaced apart from the primary winding 101 and includes a second set of sub-windings arranged in layers and connected in series between the high-side output terminal pin3 and the low-side output terminal pin4. The first shield layer 103 is arranged between the primary winding 101 and the secondary winding 102 and electrically connected to the low-side input terminal pin6. The second shield layer 104 is arranged between the first shield layer 103 and the secondary winding 102 and electrically connected to one of the second set of sub-windings nearest to the primary winding 101. The second shield layer 104 is at a distance from the first shield layer 103.

In some embodiments, as shown in Fig. 3, the first set of sub-windings of the primary winding 101 include a first sub-winding L1, a second sub-winding L2, a third sub-winding L3, and a fourth sub-winding L4 arranged in order. The secondary winding 102 includes a fifth sub-winding L5, a sixth sub-winding L6, a seventh sub-winding L7, and an eighth sub-winding L8 arranged in order. The high-side input terminal pin5 is electrically connected to an outer tap of the second sub-winding L2. An inner tap of the second sub-winding L2 is electrically connected to an inner tap of the first sub-winding L1. An outer tap of the first sub-winding L1 is electrically connected to an outer tap of the fourth sub-winding L4. An inner tap of the fourth sub-winding L4 is electrically connected to an inner tap of the third sub-winding L3. An outer tap of the third sub-winding L3 is electrically connected to the low-side input terminal pin6. The first shield layer 103 is electrically connected to the low-side input terminal pin6. The high-side output terminal pin3 is electrically connected to an outer tap of the sixth sub-winding L6. An inner tap of the sixth sub-winding L6 is electrically connected to an inner tap of the fifth sub-winding L5. An outer tap of the fifth sub-winding L5 is electrically connected to an outer tap of the eighth sub-winding L8. An inner tap of the eighth sub-winding L8 is electrically connected to an inner tap of the seventh sub-winding L7. An outer tap of the seventh sub-winding L7 is electrically connected to the low-side output terminal pin4. The second shield layer 104 is electrically connected to the fifth sub-winding L5, e.g., to the outer tap or other positions of the fifth sub-winding L5.

It is to be understood that the structure of the communication transformer 100 as shown in Fig. 3 is merely exemplary, without suggesting any limitation as to the scope of the present disclosure. In other embodiments, the first set of sub-windings of the primary winding 101 and the second set of sub-windings of the secondary winding 102 may include other numbers of sub-windings. For example, the first set of sub-windings may include one or more additional sub-windings arranged between the first sub-winding L1 and the fourth sub-winding L4, and the second set of sub-windings may include one or more additional sub-windings arranged between the fifth sub-winding L5 and the eighth sub-winding L8.

In an embodiment, each of the first shield layer 103 and the second shield layer 104 is formed from a metal sheet. In another embodiment, each of the first shield layer 103 and the second shield layer 104 is formed by winding a metal line. In other embodiments, each of the first shield layer 103 and the second shield layer 104 may be formed in other manners. The scope of the present disclosure is not intended to be limited in this respect.

Fig. 4 illustrates a schematic operation principle of the signal transmitting circuit as shown in Fig. 1 when using the communication transformer as shown in Fig. 3. As shown in Figs. 3 and 4, through using the first shield layer 103 and the second shield layer 104, the capacitive coupling between the high-side input terminal pin5 and the high-side output terminal pin3 and the capacitive coupling between the high-side input terminal pin5 and the low-side output terminal pin4 can be blocked, which will reduce the values of the parasitic capacitances C ₅₃ and C ₅₄. In this way, the conducted RF interference may be at least partially prevented from being transmitted from the high-side input terminal pin5 to the high-side output terminal pin3 and the low-side output terminal pin4 via the parasitic capacitance C ₅₃ and the parasitic capacitance C ₅₄. In addition, with the above arrangement, an additional capacitance C _addi can be generated between the first shield layer 103 and the second shield layer 104, which can increase the parasitic capacitance C ₆₄ between the low-side input terminal pin6 and the low-side output terminal pin4 and thus increase a ratio between the parasitic capacitance C ₆₄ and the parasitic capacitance C ₆₃, i.e., C ₆₄/C ₆₃. In this way, a larger part of the EFT interference will be transmitted from the low-side input terminal pin6 to the low-side output terminal pin4 via the parasitic capacitance C ₆₄ and thus be transmitted into the ground EM. Therefore, with the first shield layer 103 and the second shield layer 104, the anti-interference ability of the communication transformer 100 will be significantly improved. Further, since the cost of the first shield layer 103 and the second shield layer 104 is much lower than the Y-capacitors CY, the overall cost of the signal transmitting circuit 200 could be reduced.

Fig. 5 illustrates a schematic structural view of a communication transformer in accordance with another embodiment of the present disclosure. The structure of the communication transformer 100 as shown in Fig. 5 is similar to that of the communication transformer 100 as shown in Fig. 2, except that the line connection manner is changed. In the following, only differences between the communication transformer 100 as shown in Fig. 5 and the communication transformer 100 as shown in Fig. 2 will be described, and the same parts therebetween will not be described in detail.

In some embodiments, as shown in Fig. 5, the high-side input terminal pin5 is electrically connected to an outer tap of the first sub-winding L1. An inner tap of the first sub-winding L1 is electrically connected to an inner tap of the second sub-winding L2. An outer tap of the second sub-winding L2 is electrically connected to an outer tap of the third sub-winding L3. An inner tap of the third sub-winding L3 is electrically connected to an inner tap of the fourth sub-winding L4. An outer tap of the fourth sub-winding L4 is electrically connected to the low-side input terminal pin6. The high-side output terminal pin3 is electrically connected to an outer tap of the eighth sub-winding L8. An inner tap of the eighth sub-winding L8 is electrically connected to an inner tap of the seventh sub-winding L7. An outer tap of the seventh sub-winding L7 is electrically connected to an outer tap of the sixth sub-winding L6. An inner tap of the sixth sub-winding L6 is electrically connected to an inner tap of the fifth sub-winding L5. An outer tap of the fifth sub-winding L5 is electrically connected to the low-side output terminal pin4.

As shown in Fig. 5, since the eighth sub-winding L8 is one of the second set of sub-windings farthest away from the first winding 101, the parasitic capacitance C ₅₃ and the parasitic capacitance C ₆₃ can be reduced. In this way, the conducted RF interference may be at least partially prevented from being transmitted from the high-side input terminal pin5 to the high-side output terminal pin3, and the EFT interference may be at least partially prevented from being transmitted from the low-side input terminal pin6 to the high-side output terminal pin3. Therefore, the anti-interference ability of the communication transformer 100 will be significantly improved.

Fig. 6 illustrates a schematic structural view of a communication transformer in accordance with yet another embodiment of the present disclosure. The structure of the communication transformer 100 as shown in Fig. 6 is a combination of the structure of communication transformer 100 as shown in Fig. 3 and the communication transformer 100 as shown in Fig. 5. That is, in the communication transformer 100 as shown in Fig. 6, a pair of shield layers are provided and the line connection manner of the communication transformer 100 is changed.

In the embodiment as shown in Fig. 6, the high-side input terminal pin5 is electrically connected to an outer tap of the first sub-winding L1. An inner tap of the first sub-winding L1 is electrically connected to an inner tap of the second sub-winding L2. An outer tap of the second sub-winding L2 is electrically connected to an outer tap of the third sub-winding L3. An inner tap of the third sub-winding L3 is electrically connected to an inner tap of the fourth sub-winding L4. An outer tap of the fourth sub-winding L4 is electrically connected to the low-side input terminal pin6. The first shield layer 103 is electrically connected to the low-side input terminal pin6. The high-side output terminal pin3 is electrically connected to an outer tap of the eighth sub-winding L8. An inner tap of the eighth sub-winding L8 is electrically connected to an inner tap of the seventh sub-winding L7. An outer tap of the seventh sub-winding L7 is electrically connected to an outer tap of the sixth sub-winding L6. An inner tap of the sixth sub-winding L6 is electrically connected to an inner tap of the fifth sub-winding L5. An outer tap of the fifth sub-winding L5 is electrically connected to the low-side output terminal pin4. The second shield layer 104 is electrically connected to the fifth sub-winding L5.

As shown in Fig. 6, through inserting the first shield layer 103 and the second shield layer 104 and changing the line connection manner of the communication transformer 100, the parasitic capacitances C ₆₃, C ₅₃ and C ₅₄ can be reduced and the parasitic capacitance C ₆₄ can be increased. In this way, the EFT interference and the conducted RF interference can be prevented from being transmitted to the high-side output terminal pin3, such that the anti-interference ability of the communication transformer 100 can be significantly improved.

Fig. 7 illustrates a schematic operation principle of the signal transmitting circuit as shown in Fig. 1 when using the communication transformer as shown in Fig. 6. As shown in Fig. 7, the conducted RF interference may be prevented from being transmitted from the high-side input terminal pin5 to the high-side output terminal pin3 and the low-side output terminal pin4, and the EFT interference can be prevented from being transmitted from the low-side input terminal pin6 to the high-side output terminal pin3 and can mainly be transmitted from the low-side input terminal pin6 to the low-side output terminal pin4 and thus transmitted into the ground EM. Thus, a current I ₂ caused by the interferences will be injected in to the ground EM and will not affect the quality of the signals transmitted by the signal transmitting circuit 200.

In the embodiments described above with reference to Figs. 1-7, the signal transmitting circuit 200 is an example application scenario of the communication transformer 100. It is to be understood that the communication transformer 100 may be used in various electronic devices so as to improve the anti-interference ability of the communication transformer 100. For example, an electronic device may include a printed circuit board and the communication transformer 100 described above. The communication transformer 100 may be arranged on the printed circuit board.

It should be appreciated that the above detailed embodiments of the present disclosure are only to exemplify or explain principles of the present disclosure and not to limit the present disclosure. Therefore, any modifications, equivalent alternatives and improvements, etc. without departing from the spirit and scope of the present disclosure shall be included in the scope of protection of the present disclosure. Meanwhile, appended claims of the present disclosure aim to cover all the variations and modifications falling under the scope and boundary of the claims or equivalents of the scope and boundary.

Claims

A communication transformer (100) comprising:

a primary winding (101) comprising a first set of sub-windings arranged in layers and connected in series between a high-side input terminal (pin5) and a low-side input terminal (pin6) ;

a secondary winding (102) spaced apart from the primary winding (101) and comprising a second set of sub-windings arranged in layers and connected in series between a high-side output terminal (pin3) and a low-side output terminal (pin4) ;

a first shield layer (103) arranged between the primary winding (101) and the secondary winding (102) and electrically connected to the low-side input terminal (pin6) ; and

a second shield layer (104) arranged between the first shield layer (103) and the secondary winding (102) and electrically connected to one of the second set of sub-windings nearest to the primary winding (101) , the second shield layer (104) being at a distance from the first shield layer (103) .
The communication transformer (100) according to claim 1, wherein the first set of sub-windings comprise a first sub-winding (L1) , a second sub-winding (L2) , a third sub-winding (L3) , and a fourth sub-winding (L4) ,

wherein the first sub-winding (L1) is one of the first set of sub-windings farthest away from the secondary winding (102) , and the fourth sub-winding (L4) is one of the first set of sub-windings nearest to the secondary winding (102) ,

wherein the second set of sub-windings comprise a fifth sub-winding (L5) , a sixth sub-winding (L6) , a seventh sub-winding (L7) , and an eighth sub-winding (L8) , and

wherein the fifth sub-winding (L5) is one of the second set of sub-windings nearest to the primary winding (101) , and the eighth sub-winding (L8) is one of the second set of sub-windings farthest away from the primary winding (101) .
The communication transformer (100) according to claim 2, wherein the high-side input terminal (pin5) is electrically connected to an outer tap of the second sub-winding (L2) ,

wherein an inner tap of the second sub-winding (L2) is electrically connected to an inner tap of the first sub-winding (L1) ,

wherein an outer tap of the first sub-winding (L1) is electrically connected to an outer tap of the fourth sub-winding (L4) ,

wherein an inner tap of the fourth sub-winding (L4) is electrically connected to an inner tap of the third sub-winding (L3) , and

wherein an outer tap of the third sub-winding (L3) is electrically connected to the low-side input terminal (pin6) .
The communication transformer (100) according to claim 2, wherein the high-side output terminal (pin3) is electrically connected to an outer tap of the sixth sub-winding (L6) ,

wherein an inner tap of the sixth sub-winding (L6) is electrically connected to an inner tap of the fifth sub-winding (L5) ,

wherein an outer tap of the fifth sub-winding (L5) is electrically connected to an outer tap of the eighth sub-winding (L8) ,

wherein an inner tap of the eighth sub-winding (L8) is electrically connected to an inner tap of the seventh sub-winding (L7) , and

wherein an outer tap of the seventh sub-winding (L7) is electrically connected to the low-side output terminal (pin4) .
The communication transformer (100) according to claim 2, wherein the high-side input terminal (pin5) is electrically connected to an outer tap of the first sub-winding (L1) ,

wherein an inner tap of the first sub-winding (L1) is electrically connected to an inner tap of the second sub-winding (L2) ,

wherein an outer tap of the second sub-winding (L2) is electrically connected to an outer tap of the third sub-winding (L3) ,

wherein an inner tap of the third sub-winding (L3) is electrically connected to an inner tap of the fourth sub-winding (L4) , and

wherein an outer tap of the fourth sub-winding (L4) is electrically connected to the low-side input terminal (pin6) .
The communication transformer (100) according to claim 2, wherein the high-side output terminal (pin3) is electrically connected to an outer tap of the eighth sub-winding (L8) ,

wherein an inner tap of the eighth sub-winding (L8) is electrically connected to an inner tap of the seventh sub-winding (L7) ,

wherein an outer tap of the seventh sub-winding (L7) is electrically connected to an outer tap of the sixth sub-winding (L6) ,

wherein an inner tap of the sixth sub-winding (L6) is electrically connected to an inner tap of the fifth sub-winding (L5) , and

wherein an outer tap of the fifth sub-winding (L5) is electrically connected to the low-side output terminal (pin4) .
The communication transformer (100) according to claim 2, wherein the first set of sub-windings further comprise one or more additional sub-windings arranged between the first sub-winding (L1) and the fourth sub-winding (L4) .
The communication transformer (100) according to claim 2, wherein the second set of sub-windings further comprise one or more additional sub-windings arranged between the fifth sub-winding (L5) and the eighth sub-winding (L8) .
The communication transformer (100) according to claim 1, wherein each of the first shield layer (103) and the second shield layer (104) is formed from a metal sheet or a metal line.
An electronic device comprising:

a printed circuit board; and

a communication transformer (100) according to any of claims 1-9 arranged on the printed circuit board.