JP4586799B2 - Pulse transformer circuit - Google Patents

Description

  The present invention relates to a transformer circuit, and more particularly to a core shape and a winding structure of a transformer circuit.

  A pulse transformer is used as a transformer of a high-frequency digital signal line such as Ethernet (registered trademark) (see, for example, Patent Document 1).

Conventional pulse transformer has a toroidal core primary winding Sen及 beauty secondary winding is wound on the structure, a pair of input terminals by the primary winding of the transformer, in the primary winding A point and a pair of output ends by the secondary winding 43 of the transformer.
JP-A-7-161535

Conventional pulse transformer described above, was to form a primary winding Sen及 beauty secondary winding by winding a plurality of wires into a toroidal core. Also, For the middle point of the primary winding, it has been formed by connecting the ends of two wires.

However, the winding operation of the toroidal core is very complicated, there is a problem that automation is difficult. Further, since the wiring state becomes complicated due to the connection between the wires, there are problems such as variations in characteristics and a decrease in reliability. Moreover, since the wiring state is complicated, there is a problem that it is difficult to reduce the size of the product.

  Accordingly, an object of the present invention is to provide a transformer circuit that facilitates winding work around a core member and that can take the middle point of the winding regardless of the routing of the wire.

  The object of the present invention includes a transformer component and a printed circuit board on which the transformer component is mounted. The transformer component is wound around the core member having a core portion made of a rod-shaped magnetic body. A printed circuit board comprising: first to fourth coils made of wires; and first to fourth terminal electrode pairs provided corresponding to the first to fourth coils and connected to both ends of each coil. Are provided in the mounting surface of the transformer component, and the first to fourth land pattern pairs provided corresponding to the positions of the first to fourth terminal electrode pairs in the mounting region of the transformer component. This is achieved by a transformer circuit comprising a connection conductor pattern connecting one land of the first to fourth land pattern pairs and the other land of the first to fourth land pattern pairs.

  According to the present invention, only by mounting the transformer component on the printed circuit board, the ends of the coils constituting the transformer component are connected to each other via the connection conductor pattern, so that it is not necessary to connect the wires in advance. Thus, the winding work can be facilitated. In addition, since the wiring situation is simplified, problems such as variations in characteristics and a decrease in reliability can be solved, and the product can be downsized.

  In the present invention, it is preferable that the first to fourth terminal electrode pairs are arranged in order, and two terminal electrodes constituting each terminal electrode pair face each other. In the present invention, it is preferable that the first to fourth terminal electrode pairs are respectively formed at both ends of the core portion. According to this, the layout of each coil terminal can be simplified, and thereby the product can be reduced in size.

  In the present invention, the core member further includes first and second flange portions provided at both ends of the core portion, and a plate-like core connecting the first and second flange portions, It is preferable that one terminal electrode of the fourth terminal electrode pair is provided in the first collar part, and the other terminal electrode of the first to fourth terminal electrode pairs is provided in the second collar part. According to this, the winding work to a core can be performed easily.

  In the present invention, the connection conductor pattern includes a first connection conductor pattern and a second connection conductor pattern, whereby the first input terminal serving as one end of the primary winding, the other end of the primary winding, A second input terminal, a midpoint of the primary winding, a first output terminal serving as one end of the secondary winding, and a second output terminal serving as the other end of the secondary winding. Is preferred. In this case, the terminal electrode pair located at one end of the first to fourth terminal electrode pairs is the first and second input terminals, and the other of the first to fourth terminal electrode pairs. The terminal electrode pair positioned at the end is preferably the first and second output terminals. According to this, a pair of input signal lines can be laid in parallel on the printed circuit board, and a pair of output signal lines can be laid in parallel. Therefore, the occupied area of the wiring pattern does not increase more than necessary, and high symmetry can be ensured.

  In the present invention, it is preferable that the first and second connection conductor patterns are arranged in parallel and close to each other. According to this, impedance matching between windings becomes easy, and impedance matching can be surely taken by setting other conditions such as the thickness of the substrate and the pattern width.

  In the present invention, it is preferable that the first to fourth coils have substantially the same length. In this case, the first to fourth coils are preferably configured as one stranded wire. Alternatively, in the half region of the core part, the first and second coils are bifilar wound on the inner periphery and the third and fourth coils are bifilar wound on the outer periphery, while the remaining half of the core part In this area, the third and fourth coils may be bifilar wound on the inner periphery, and the first and second coils may be bifilar wound on the outer periphery. With these winding structures, it is easy to make the wire lengths of the winding portions the same, and the wires can be coupled with a good balance, and variations in the characteristics of the transformer circuit can be suppressed.

  As described above, according to the present invention, it is possible to provide a transformer circuit that can easily perform the winding work around the core and can take a middle point regardless of the wire connection.

  Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

  FIG. 1 is a schematic perspective view showing the external structure of a transformer circuit according to the first embodiment of the present invention. FIG. 2 is a schematic bottom view showing the structure of the bottom surface of the transformer component.

  As shown in FIGS. 1 and 2, the transformer circuit 100 includes a transformer component 10 and a printed circuit board 30 on which the transformer component 10 is mounted.

  The transformer component 10 includes a core member 11 having a rod-shaped core part, first to fourth wires 14 to 17 wound around the core part, and first ends connected to both ends of the first wire 14. One terminal electrode pair 18, a second terminal electrode pair 19 to which both ends of the second wire 15 are connected, a third terminal electrode pair 20 to which both ends of the third wire 16 are connected, And a fourth terminal electrode pair 21 to which both ends of the fourth wire 17 are connected.

  The core member 11 includes a drum core 12 and a plate-like core 13 attached to the top of the drum core 12. The drum core 12 includes a rod-shaped core portion 12A and first and second flange portions 12B and 12C provided at both ends of the core portion 12A, respectively, and has an integrated configuration. . The plate-like core 13 is separate from the drum core 12, but is bonded and fixed to the upper surfaces of the first and second flanges 12B and 12C. Thus, the drum core 12 and the plate core 13 constitute one closed magnetic path.

The core portion 12A of the drum core 12 four wires 14 to 17 is wound in the same direction, whereby the first to fourth coil L ₁ through L ₄ is configured. The four wires 14 to 17 are preferably wound in a highly coupled state. In order to set the first to fourth wires 14 to 17 in a highly coupled state, as shown in FIG. 3, the first to fourth wires 14 to 17 may be configured as one stranded wire, Or you may comprise as a twisted wire of a pair wire. Further, as shown in FIG. 4, the first to fourth wires 14 to 17 may be integrated with a covering 22 in a state where they are formed as one stranded wire. Alternatively, the first to fourth wires 14 to 17 may be a bi-layered bifilar winding. That is, as shown in FIG. 5, in the half region of the core portion 12A, the coils 14 and 15 are bifilar wound on the inner periphery, and the coils 16 and 17 are bifilar wound on the outer periphery, while the core portion 12A In the remaining half region, the coils 16 and 17 may be bifilar wound on the inner periphery, and the coils 14 and 15 may be bifilar wound on the outer periphery. In these cases, since the wire lengths of the winding portions of the first to fourth wires 14 to 17 are substantially the same, the wires 14 to 17 can be coupled in a well-balanced manner, and the coil L _{1 is used.} or the characteristics of L ₄ is substantially the same.

  When the wire is a single strand, a pair of strands, or two layers of bifilar winding, the four wires are preferably bundled from a position in contact with the core portion 12A. In this way, the stray capacitance can be reduced because the lead portions are separated. In addition, the wiring of the lead wire is facilitated, and the manufacture of the transformer component 10 is facilitated. Further, when the wire is a single strand, a pair of strands, or two layers of bifilar winding, four wires are formed at a hollow position between the terminal electrode and a position in contact with the core portion 12A. You may start to bundle. In this way, since the coupling is further improved, the characteristics can be further improved.

  The first to fourth terminal electrode pairs 18 to 21 are provided on the bottom surfaces of the first and second flange portions 12B and 12C provided at both ends of the core portion 12A. In particular, one terminal electrode 18A to 21A is provided on the bottom surface of the first flange portion 12B, and the other terminal electrode 18B to 21B is provided on the bottom surface of the second flange portion 12C. These terminal electrode pairs 18 to 21 are arranged in order along the longitudinal direction of the bottom surfaces of the first and second flange portions 12B and 12C, and one terminal electrode 18A to 21A and the other terminal electrode 18B. The positions of 21B coincide with each other.

  One end 14 a of the first wire 14 is connected to one terminal electrode 18 A of the first terminal electrode pair 18, and the other end 14 b of the first wire 14 is connected to the other terminal electrode of the first terminal electrode pair 18. 18B. Similarly, one end 15a and the other end 15b of the second wire 15 are connected to one terminal electrode 19A and the other terminal electrode 19B of the second terminal electrode pair 19, respectively, and one end 16a and the other end of the third wire 16 are respectively connected. 16b is connected to one and the other terminal electrodes 20A and 20B of the third terminal electrode pair 20, respectively, and one end 17a and the other end 17b of the fourth wire 17 are connected to one and the other of the fourth terminal electrode pair 21, respectively. Terminal electrodes 21A and 21B.

  On the other hand, the printed circuit board 30 includes a first land pattern pair 32A, 32B, a second land pattern pair 33A, 33B, and a third land pattern pair 34A, 34B provided in the mounting area 31 of the transformer component 10. And a fourth land pattern pair 35A, 35B. Further, the printed circuit board 30 includes a first connection conductor pattern 36 that connects one land 32A of the first land pattern pair 32 and the other land 34B of the third land pattern pair 34, and a second land pattern. A second connection conductor pattern 37 that connects a land 33A on one end side of the pair 33 and a land 35B on the other end side of the fourth land pattern pair 35 is provided.

  The first and second connection conductor patterns 36 and 37 are provided in the mounting region 31 of the transformer component 10 and are formed directly below the transformer component 10. Therefore, the transformer component mounting area 31 can be effectively used, and other component mounting areas on the printed circuit board can be made wider. The first and second connection conductor patterns 36 and 37 are wired in parallel with each other close to each other. Thereby, the shift | offset | difference of the impedance resulting from the connection conductor patterns 36 and 37 can be prevented.

  FIG. 6 is a circuit diagram of the transformer circuit 100.

As shown in FIG. 6, one end of the third wire 16 constituting the coil L ₃ is connected to the land 34 A forming the input terminal 1, and the other end of the wire 16 is connected to the coil L ₁ via the connection conductor pattern 36. The first wire 14 is connected to one end of the first wire 14, and the other end of the first wire is connected to the land 32 </ b> B forming the input terminal 2. One end of the fourth wire 17 constituting the coil L ₄ is connected to the land 35 A forming the output terminal 1, and the other end of the wire 17 is connected to the second wire 15 via the second connection conductor pattern 37. Connected to one end. Thus, the transformer circuit is configured with a primary winding consisting of coils L ₃ and the coil L _1, and a secondary winding consisting of coils L ₄ and the coil L _2. Further, the midpoint of the primary winding is formed by the lands 34 </ b> B and 33 </ b> A that are connection points between the third wire 16 and the first wire 14.

  As described above, according to the present embodiment, since the drum core 12 is used as the core member 11, the wires 14 to 17 can be easily wound, and automatic winding is also possible. In addition, since the wire lengths of the winding portions of the first to fourth wires 14 to 17 can be set to be substantially the same, variations in the characteristics of the transformer circuit can be suppressed, and the product can be downsized. You can also. Further, terminal electrode pairs 18 to 21 of the respective wires are provided on the bottom surface of the drum core 12, and the connection between the wires is performed not by connecting the ends of the wires but by connecting conductor patterns 36 and 37 on the printed circuit board 30. Therefore, it becomes easy to secure the connection between the wires and the middle point of the winding.

  FIGS. 7A and 7B are diagrams showing a configuration of a transformer circuit according to the second embodiment of the present invention. FIG. 7A is a circuit diagram, and FIG. The upper pattern layout is shown.

  As shown in FIGS. 7A and 7B, the transformer circuit 200 includes a first electrode terminal pair 18 located outside one of the first to fourth terminal electrode pairs 18 to 21. The terminal electrode pair 21 which comprises two input terminals and is located on the other outer side is characterized by constituting first and second output terminals. Therefore, in the transformer component 10, the other end 14b of the first wire 14 is connected to the terminal electrode 19B, and the other end 15b of the second wire 15 is connected to the terminal electrode 18B. The other end 14b of the first wire 14 is connected to the terminal electrode 19B, and the other end 15b of the second wire 15 is connected to the terminal electrode 18B. Further, the first connection conductor pattern 36 connects the lands 33A and 33B, and the second connection conductor pattern 37 connects the lands 34A and 34B. Since other configurations are the same as those of the first embodiment, detailed description thereof is omitted.

  According to the present embodiment, since the pair of input terminals and output terminals are arranged on the outermost side of the terminal electrode arrangement, the pair of input signal lines 1 and 2 can be laid in parallel on the printed circuit board 30. In addition, the pair of output signal lines 3 and 4 can be laid in parallel. This eliminates the need for bypassing the wiring pattern on the printed circuit board 30. Therefore, the occupied area of the wiring pattern on the printed board 30 does not increase more than necessary, and high symmetry can be ensured. As a result, it is possible to simultaneously reduce the size of the entire apparatus and improve the signal quality.

  FIGS. 8A and 8B are diagrams showing a configuration of a transformer circuit according to the third embodiment of the present invention. FIG. 8A is a circuit diagram, and FIG. 8B is a printed circuit board 30. The upper pattern layout is shown.

As shown in FIG. 8 (a) and (b), the transformer circuit 300 includes a primary winding consisting of coils _{L 4} and the coil _{L 3,} and a secondary winding consisting of coils _{L 2} and the coil _{L 1} It is characterized in that it is configured as a transformer circuit. In this case, the midpoint of the primary winding is formed by the lands 35 </ b> B and 34 </ b> A that are connection points between the fourth wire 17 and the third wire 16. The first and second connection conductor patterns 36 and 37 are wired in parallel with each other close to each other. Thereby, the shift | offset | difference of the impedance resulting from the connection conductor patterns 36 and 37 can be prevented. Since other configurations are the same as those of the first embodiment, detailed description thereof is omitted. As described above, according to the present embodiment, since the connection between the wires is performed by routing the connection conductor patterns 36 and 37 on the printed circuit board 30, the same effects as those of the first embodiment can be obtained.

  FIGS. 9A and 9B are diagrams showing the configuration of a transformer circuit according to the fourth embodiment of the present invention. FIG. 9A is a circuit diagram, and FIG. 9B is a printed circuit board 30. The upper pattern layout is shown.

As shown in FIG. 9 (a) and (b), the transformer circuit 300 includes a said coil L ₁ through coil L ₄ in that connected in series. Thereby, a transformer having a winding ratio of 3 to 1 can be configured. Here, as in the first embodiment, the first and second connection conductor patterns 36 and 37 are wired close to each other in parallel. Thereby, the shift | offset | difference of the impedance resulting from the connection conductor patterns 36 and 37 can be prevented. Since other configurations are the same as those of the first embodiment, detailed description thereof is omitted. As described above, according to the present embodiment, since the connection between the wires is performed by routing the connection conductor patterns 36 and 37 on the printed circuit board 30, the same effects as those of the first embodiment can be obtained.

  FIGS. 10A and 10B are diagrams showing the configuration of a transformer circuit according to the fifth embodiment of the present invention. FIG. 10A is a circuit diagram, and FIG. 10B is a printed circuit board 30. The upper pattern layout is shown.

As shown in FIG. 10 (a) and (b), the transformer circuit 300 is characterized all the coils L ₁ through coil L ₄ in that connected in series. As a result, one coil having four times the number of turns can be formed. In this case, the first to third connection conductor patterns 36 to 38 are used. Since other configurations are the same as those of the first embodiment, detailed description thereof is omitted. As described above, according to the present embodiment, since the connection between the wires is performed by routing the connection conductor patterns 36 to 38 on the printed board 30, the same effects as those of the first embodiment can be obtained.

  The present invention is not limited to the above embodiments, and various modifications can be made without departing from the spirit of the present invention, and these are also included in the scope of the present invention. Needless to say.

  For example, in the above embodiment, the connection conductor pattern is formed on the front surface (the same surface as the land pattern) of the printed circuit board, but may be formed on the back surface of the printed circuit board through the through-hole conductor.

FIG. 1 is a schematic perspective view showing the external structure of a transformer circuit according to the first embodiment of the present invention. FIG. 2 is a schematic bottom view showing the structure of the bottom surface of the transformer component. In FIG. 3, the first to fourth wires 14 to 17 are configured as one stranded wire. FIG. 4 is a schematic cross-sectional view showing the first to fourth wires 14 to 17 configured as two pairs of vertical and horizontal pairs. FIG. 5 is a schematic cross-sectional view illustrating a configuration of a bilayer bifilar winding. FIG. 6 is a circuit diagram of the transformer circuit 100. FIG. 7 is a circuit diagram of a transformer circuit according to the second embodiment of the present invention. FIGS. 8A and 8B are diagrams showing a configuration of a transformer circuit according to the third embodiment of the present invention. FIG. 8A is a circuit diagram, and FIG. 8B is a printed circuit board 30. The upper pattern layout is shown. FIGS. 9A and 9B are diagrams showing the configuration of a transformer circuit according to the fourth embodiment of the present invention. FIG. 9A is a circuit diagram, and FIG. 9B is a printed circuit board 30. The upper pattern layout is shown. FIGS. 10A and 10B are diagrams showing a configuration of a transformer circuit according to the fifth embodiment of the present invention. FIG. 10A is a circuit diagram, and FIG. 10B is a printed circuit board 30. The upper pattern layout is shown.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Transformer part 11 Core member 12 Drum core 12A Core part 12B Collar part 12C Collar part 13 Plate-like core 14 First wire 14a One end 14b of the first wire 15 Other end 15 of the first wire Second wire 15a Second One end 15b of the second wire 16 Other end 16 of the second wire 16a Third wire 16a One end 16b of the third wire 17 Other end of the third wire 17 Fourth wire 17a One end of the fourth wire 17b Other end 18 First terminal electrode pair 18A One terminal electrode 18B Other terminal electrode 19 Second terminal electrode pair 19A One terminal electrode 19B Other terminal electrode 20 Third terminal electrode pair 20A One terminal electrode 20B The other Terminal electrode 21 Fourth terminal electrode pair 21A One terminal electrode 21B The other terminal electrode 30 Printed circuit board 31 Transformer mounting region 32 First land pattern Land 32B One land 32B Other land 33 Land pattern pair 33A One land 33B Other land 34 Land pattern pair 34A One land 34B The other land 35 Land pattern pair 35A One land 35B The other land 36 1st Connection conductor pattern 37 second connection conductor pattern 38 third connection conductor pattern 41 toroidal core 42 primary winding 42a one input end 42b other input end 42c middle point 43 secondary winding 43a one output end 43b other Output terminal 22 covering 100 transformer circuit 200 transformer circuit 300 transformer circuit 600 pulse transformer L ₁ first coil L ₂ second coil L ₃ third coil L ₄ fourth coil

Claims (6)

A pulse transformer component and a printed circuit board on which the pulse transformer component is mounted;
The pulse transformer component is
A core member having a core portion made of a rod-shaped magnetic body;
First to fourth coils made of wires wound around the core;
First to fourth terminal electrodes respectively connected to one ends of the first to fourth coils;
Fifth to eighth terminal electrodes respectively connected to the other ends of the first to fourth coils,
The first to fourth terminal electrodes and the fifth to eighth terminal electrodes are each arranged in order along a predetermined direction,
The first to fourth terminal electrodes are opposed to the fifth to eighth terminal electrodes, respectively.
Two of the first to fourth coils constitute a primary winding of the pulse transformer component, and the other two of the first to fourth coils constitute a secondary winding of the pulse transformer component. Configure
The printed circuit board is
First to eighth lands provided corresponding to the positions of the first to eighth terminal electrodes in the mounting area of the pulse transformer component,
A land which is provided in a mounting surface of the pulse transformer component and to which one end of two coils constituting the primary winding of the pulse transformer component among the first to fourth lands is connected; A first connection conductor pattern for connecting the other end of the two coils constituting the primary winding of the pulse transformer component among the fifth to eighth lands. ,
A land provided on a mounting surface of the pulse transformer component, to which one end of two coils constituting the secondary winding of the pulse transformer component among the first to fourth lands is connected. And a second connecting conductor that connects the other end of the two coils constituting the secondary winding of the pulse transformer component among the fifth to eighth lands. With patterns,
Two lands which the first connection conductive patterns are connected, the first and seventh lands, the second and sixth lands, as well as in one of the first and sixth lands Yes,
The two lands to which the second connection conductor pattern is connected are the second and eighth lands when the first connection conductor pattern is connected to the first and seventh lands. When the first connection conductor pattern is connected to the second and sixth lands, they are the third and seventh lands, and the first connection conductor pattern is the first and sixth lands. The third and eighth lands when connected to
It said first and second connection conductor pattern is wired in parallel close to each other pulse transformer circuit, wherein the Turkey. Claim 1, wherein the first to fourth terminal electrodes are formed on one end of the winding core portion, the fifth to eighth terminal electrodes is characterized in that it is formed at the other end of the winding core portion transformer circuit according to. The core member further includes first and second flange portions respectively provided at both ends of the core portion, and a plate-like core that connects between the first and second flange portions,
The said 1st thru | or 4th terminal electrode is provided in the said 1st collar part, The said 5th thru | or 8th terminal electrode is provided in the said 2nd collar part, The Claim 2 characterized by the above-mentioned. The transformer circuit described. Transformer circuit as claimed in any one of claims 1 to 3, wherein the length of the first to fourth coils are substantially identical. The transformer circuit according to claim 4 , wherein the first to fourth coils are configured as one stranded wire. In the half region of the core portion, the first and second coils are bifilar wound on the inner periphery, and the third and fourth coils are bifilar wound on the outer periphery, while the core portion in the remaining half of the region, the inner wound bifilar said third and fourth coil at the peripheral, according to claim 4, characterized in that by winding bifilar said first and second coils at the outer periphery Transformer circuit.

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