JP2555347Y2 - Interface module - Google Patents

Description

[Detailed description of the invention]

[0001]

The present invention relates to a LAN (Local Area N)
The present invention relates to an interface module used for communication between other computers, communication between data terminals, and the like.

[0002]

2. Description of the Related Art FIGS. 8 and 9 show a conventional example. In FIGS. 8 and 9, 1 is an interface circuit, 2 is a driver, 3 is a receiver, and 4 and 5 are low-pass filters.
w Pass Filter), 6 and 7 indicate pulse transformers.

Description of interface circuit: see FIG. 8 Conventionally, when a digital signal is transmitted in LAN or other inter-computer communication, inter-data terminal communication, or the like, particularly low radiation noise from a transmission path is low. When things were required, interface circuits were used.

FIG. 8 shows an example of such an interface circuit. As shown, the interface circuit 1
Is composed of a transmission unit and a reception unit. The transmitting section is composed of the low-pass filter 4 and the pulse transformer 6, and the receiving section is composed of the low-pass filter 5 and the pulse transformer 7.

The driver of the interface circuit is connected to the driver 2, and the receiver of the interface circuit is connected to the receiver 3. The pulse transformers 6 and 7 are transformers (insulation transformers) for electrically separating the input side and the output side (insulation between input and output). In addition, the low-pass filters 6 and 7 provide normal mode noise (such as a harmonic component of a transmission line) and common mode noise (for a plurality of lines).
This is a filter for removing noise such as noise generated at the same potential with respect to the ground.

Description of the operation of the interface circuit
.. See FIG. 8 The interface circuit operates, for example, as follows. The input signal on the transmitting side is sent from the driver 2 to the low-pass filter 4 of the transmitting unit.

The input signal to the transmitting section is, for example, a square wave digital signal. When this signal passes through the low-pass filter 4, the high frequency is removed and the signal becomes a signal having a waveform close to a sine wave.

After that, the signal that has passed through the low-pass filter 4 is input to the pulse transformer 6, converted, output as a transmission side, and transmitted. Also, the signal of the receiving side input is
This is a signal having a substantially sinusoidal shape (a signal containing noise mixed in the transmission path), and is first input to the pulse transformer 7 and converted. After that, the signal converted by the pulse transformer 7 has its noise removed by the low-pass filter 5 and is sent to the receiver 3.

The signals handled by the above interface circuit are:
For example, in the case of a LAN, the transmission speed is 10 Mbit / sec. Description of Mounting Form of Interface Circuit Conventionally, when the above-described interface circuit is actually used, one mounted on a printed board or the like in the following forms (interface module) has been used.

-1: Example 1 Components of a pulse transformer and components such as a coil and a capacitor constituting a low-pass filter (discrete components)
Is mounted on one side of a printed circuit board to form an interface module.

-2: Example 2 Using a modularized low-pass filter, parts of this low-pass filter and parts of a pulse transformer are mounted on one side of a printed circuit board to form an interface module.

The interface module of the above-described implementation has the following problems. That is, (a), since discrete components are mounted on one side of the printed circuit board, miniaturization is difficult.

[0013] (b), the frequency of the signal used in the interface circuit is higher and the number of MH _Z ~ number 10 MHz _Z,
If the spacing between components is simply reduced for miniaturization, crosstalk occurs and the characteristics of common mode impedance deteriorate. Therefore, it is difficult to reduce the size while maintaining the characteristics.

(C) If components are simply mounted on both sides of the printed circuit board to reduce the size of the module, the printed board is thin, so that crosstalk occurs and the characteristics are degraded. (D) Since the frequency to be used is high, if the size is simply reduced, reproducibility at the time of assembling deteriorates, and it is difficult to obtain necessary characteristics.

In order to solve the above-mentioned problems (a) to (d), the following interface modules have been proposed. Hereinafter, the improved interface module will be described.

Description of improved interface module: see FIG. 9 FIG. 9 is a perspective view of the improved interface module.
Shown in -1: This interface module is case 8
And a printed circuit board 9 on which components such as a capacitor C, a coil L, and a pulse transformer constituting a low-pass filter are mounted. The transmitting unit and the receiving unit are separately arranged on both sides of the longitudinal center line XY.

The inside of the case 8 is formed in a concave shape, and a plurality of terminal pins 10 are provided in a peripheral portion thereof. In the concave portion of the case 8, the pulse transformers 6 and 7 are mounted, and the lead wires of the pulse transformers 6 and 7 are mounted on the terminal pins 10.

A printed circuit board 9 is mounted on the upper part of the case 8. On the upper and lower surfaces of the printed circuit board, low-pass filters 4 and 5 to which a coil L and a capacitor C are connected are mounted, and the terminal pins 10 are inserted into holes formed around the printed circuit board 9. It is integrated with the case 8.

In this case, a cutout is provided in a part of the printed circuit board 9 located above the pulse transformers 6 and 7, so that the pulse transformers 6 and 7 are not below the printed circuit board 9. It is like that. This facilitates the work of connecting the lead wire of the pulse transformer to the terminal pin 10 and the like. In addition, the upper part of the case 8 is integrated with, for example, a cover.

In this manner, the transmitting section and the receiving section can be independently and symmetrically arranged on both sides of the center line XY in the longitudinal direction of the interface module. Then, the interface module can be reduced in size without deteriorating the characteristics.

[0021]

Problems to be Solved by the Invention The above-mentioned conventional devices have the following problems. (1) The interface modules according to Examples 1 and 2 have the following problems (a) to (d).
That is, (a), since discrete components are mounted on one side of the printed circuit board, miniaturization is difficult.

[0022] (b), the frequency of the signal used in the interface circuit is higher and the number of MH _Z ~ number 10 MHz _Z,
If the spacing between components is simply reduced for miniaturization, crosstalk occurs and the characteristics of common mode impedance deteriorate. Therefore, it is difficult to reduce the size while maintaining the characteristics.

(C) If components are mounted on both sides of the printed circuit board to reduce the size of the module, the printed board is thin, so that crosstalk occurs and the characteristics are degraded. (D) Since the frequency to be used is high, if the size is simply reduced, reproducibility at the time of assembling deteriorates, and it is difficult to obtain necessary characteristics.

(2) The improved interface module shown in FIG. 9 has the following problems. (E) There is a useless space between the case and the printed circuit board. Therefore, miniaturization of the module is insufficient.

(F) In order to connect the case to the printed circuit board or to draw out the lead of the pulse transformer,
A large number of terminal pins are required, and the shape of the terminal pins needs to be large. Therefore, the outer shape of the module becomes large, and the miniaturization of the module is insufficient in this respect as well.

(G) In order to further reduce the size of the module, it is extremely difficult with the structure of the improved interface module. The purpose of the present invention is to solve such a conventional problem, to reduce the size and thickness of the interface module without deteriorating the characteristics, and to realize an inexpensive and highly reproducible interface module. And

[0027]

FIG. 1 is an explanatory view of the principle of the present invention. In FIG. 1, the same components as those in FIGS. 8 and 9 are denoted by the same reference numerals. Reference numeral 12 denotes a coil unit, 13 denotes a capacitor unit, and 14 denotes a common GND pattern.

The present invention is configured as follows in order to solve the above-mentioned problems. (1) An interface module in which the transmission unit and the reception unit are each composed of a pulse transformer and a low-pass filter, and the pulse transformer and the low-pass filter are mounted on a printed circuit board 9 and integrated. On one side of the longitudinal center line XY of the printed circuit board 9, the pulse transformer 6 of the transmitting unit and the low-pass filter 4 are arranged, and on the other side of the center line XY, the transmitting unit is Independently, the pulse transformer 7 and the low-pass filter 5 of the receiving unit are arranged, and the pulse transformers 6 and 7 of the transmitting and receiving unit and the low-pass filters 4 and 5 of the transmitting and receiving unit are
They were arranged at positions facing each other across the center line XY.

(2) In the above configuration (1), the low-pass filters 4 and 5 of the transmitting / receiving section are respectively replaced with the coil section 1
2 and a capacitor unit 13, only the coil unit 12 of each low-pass filter is arranged on the side of the printed circuit board 9 where the pulse transformers 6 and 7 are mounted, and the printed circuit board 9 is interposed on the other surface. The capacitor section 13 was disposed at a position facing the coil section of each low-pass filter.

(3) In the above configuration (2), a common GND pattern 14 is provided between the capacitor unit of the transmitting unit and the capacitor unit of the receiving unit on the capacitor unit mounting surface side of the printed circuit board 9. Provided, the common GND pattern 1
4 was connected to the capacitor unit 13 of the transmission / reception unit.

(4) In the above configuration (1), (2) or (3), the printed circuit board 9 on which a pair of transmission / reception units is mounted is an interface module unit, and a plurality of the interface module units are connected and integrated. As a result, a multiple interface module was obtained.

[0032]

The operation of the present invention based on the above configuration will be described with reference to FIG. The digital signal input to the transmission unit of the interface module is subjected to conversion by the pulse transformer 6 after removing noise components (such as harmonic noise and common mode noise) by the low-pass filter 4 and output to the transmission side.

The signal input to the receiving section of the interface module is first converted by the pulse transformer 7 and then the noise (such as noise mixed in the transmission path) is removed by the low-pass filter 5 and then transmitted to the receiving side. Is output.

In this case, the pulse transformers 6 and 7 are:
It has the function of electrically insulating the input and output sides of the interface module. Since the transmitting unit and the receiving unit are independently mounted on both sides of the longitudinal center line XY, the distance between them can be sufficiently large even if the interface module is downsized. For this reason, the crosstalk between the transmission unit and the reception unit can be sufficiently suppressed.

Further, since the low-pass filter and the pulse transformer are arranged along the longitudinal direction of the printed circuit board, the distance between the input and output of both the transmitting unit and the receiving unit can be sufficiently long.
Therefore, the impedance with respect to the common mode noise is increased, and the radiation noise and the like can be sufficiently removed.

That is, with the above configuration, the interface module can be sufficiently reduced in size and thickness without deteriorating the characteristics.

[0037]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below with reference to the drawings. (Description of First Embodiment) FIGS. 2 to 5 are views showing a first embodiment of the present invention.
2 to 5, the same components as those in FIGS. 1, 8, and 9 are denoted by the same reference numerals. Further, 16 is a base, 17 is a core, 18 is a winding, 19 is a lead wire, 20 is a resin, 21
Is a terminal (external electrode), 22 is a lid, 23 is a terminal, C1 to C
Reference numeral 16 indicates a capacitor, and L1 to L8 indicate coils.

Description of Interface Circuit--See FIG. 2 FIG. 2 shows an interface circuit of the first embodiment. As shown, the interface circuit 1 includes a transmission unit and a reception unit.

Then, the transmitting section transmits the low-pass filter (L
PF) 4 and a pulse transformer 6, and the receiving section is composed of a low-pass filter (LPF) 5 and a pulse transformer 7.

The low-pass filter 4 includes a capacitor section including capacitors C9 to C16 and coils L1 to L
4 and a low-pass filter 5
Is composed of a capacitor section composed of capacitors C1 to C8 and a coil section composed of coils L5 to L8.

The capacitors C1, C2, C9,
C10 is connected to a common GND line. Description of the operation of the interface circuit : see FIG. 2 The operation of the interface circuit shown in FIG.

: Explanation of interface module
··· See FIGS. 3, 4, and 5 FIG. 3 is a view of component mounting on a printed circuit board, FIG. 4 is a diagram of the internal structure of a pulse transformer, and FIG. 5 is a perspective view of an interface module.

-1: Description of a printed circuit board on which components are mounted: see FIG. 3 A printed circuit board 9 constituting an interface module
In FIG. 3, the components of the interface circuit shown in FIG. 2 are mounted, and the state is shown in FIG. 3A shows the upper surface (one side is the upper surface) of the printed circuit board, and FIG. 3B shows the lower surface (the opposite side of the upper surface is the lower surface).

Each component is mounted on the printed circuit board 9 constituting the interface module in the same arrangement as the interface circuit shown in FIG. That is, components of the transmission unit are mounted on one side (upper side in FIG. 3A and lower side in FIG. 3B) with respect to the center line XY in the longitudinal direction of the printed circuit board 9, and the other side (FIG. 3A). On the lower side and on the upper side in FIG. 3B), the components of the receiving unit are mounted.

Then, on the printed circuit board 9, the pulse transformers 6 and 7 are mounted on the right side of the figure and the low-pass filters 4 and 5 are mounted on the left side of the figure for both the transmitting unit and the receiving unit (the same arrangement as in FIG. 2). ).

That is, in both the transmitting section and the receiving section, components are arranged along the longitudinal direction of the printed circuit board, and the pulse transformers of the transmitting / receiving section and the low-pass filter are positioned with respect to the longitudinal center line XY. They are arranged at positions facing each other.

In this case, the low-pass filters 4 and 5 are composed of a coil portion and a capacitor portion, but only the coil portion is mounted on the upper surface of the printed circuit board 9 in order to make the heights of components on the printed circuit board uniform. On the lower surface, a capacitor unit is mounted.

The details are as follows. On the upper side (upper side of the figure) of the XY line of the printed circuit board 9 shown in FIG. 3A, the coils L1 to L4 of the coil unit constituting the low-pass filter 4 are mounted on the left side, and the pulse transformer 6 is mounted on the right side.
With.

Further, the X of the printed circuit board 9 shown in FIG.
Below the -Y line (the lower side in the figure), the coils L5 to L8 of the coil unit 12 constituting the low-pass filter 5 are mounted on the left side, and the pulse transformer 7 is mounted on the right side.

Further, the X of the printed circuit board 9 shown in FIG.
On the upper side of the -Y line, the capacitors C1 to C8 of the capacitor unit 13 constituting the low-pass filter 5 are mounted on the left side. On the lower side of the XY line of the printed circuit board 9 shown in FIG. 3B, the capacitors C9 to C16 of the capacitor section constituting the low-pass filter 4 are mounted on the left side.

On the lower surface of the printed circuit board 9 shown in FIG. 3B, a substantially T-shaped common GND pattern 14 extending on the XY line of the printed circuit board 9 and in the vertical direction of the drawing from the middle thereof is formed. And the capacitors C1, C2, C9,
Connect to one electrode of C10.

-2: Description of pulse transformer ... FIG.
FIG. 4 shows the internal structure of the pulse transformers 6 and 7.
4A is a plan view of the inside of the pulse transformer, and FIG. 4B is a side view of the inside of the pulse transformer.

As shown, the pulse transformers 6 and 7
This is an SMD (surface mount component) transformer. In this pulse transformer, a winding 18 is wound around a ring-shaped core 17, which is placed in a base 16 made of plastic or the like, and filled with an insulating resin 20.

The end of the lead wire 19 of the winding 18 is
While being connected to the terminal (external electrode) 21, a lid 22 is placed on the upper side of the base 16. -3: Description of Interface Module (Completed Product) —See FIG. 5 FIG. 5 is a perspective view of the interface module (completed product) of the present embodiment. As shown in the figure, the interface module has the above-described components mounted on a printed board 9 and a plurality of terminals (external electrodes) 23 provided at both ends in the longitudinal direction of the printed board 9.

The terminal 23 is connected to the pulse transformers 6 and 7 of the transmitting and receiving sections, the low-pass filters 4 and 5,
It is connected to the common GND pattern 14. The printed circuit board 9 on which the above components are mounted is provided with an insulative resin or a cover over each component to complete the product. Then, as shown in FIG. 5, the printed circuit board 9 has an interface on which a pair of transmitting units and a receiving unit are mounted.
The source module is used as one module unit.

(Explanation of Second Embodiment) FIGS. 6 and 7 show a second embodiment of the present invention.
6 and 7, the same components as those in FIGS. 1 to 5 are denoted by the same reference numerals. Also, 9A indicates an original board (printed board before division), P1, P2... Indicate V cut positions, 25 indicates a V cut, and MU1, MU2.

The second embodiment is an example in which a multiple interface module is used, and will be specifically described below. : Explanation at the time of manufacturing the interface module ...
FIG. 6 is an explanatory view of the manufacturing process of the interface module.
Shown in At the time of manufacturing the interface module, the components of the transmission unit and the reception unit are mounted on the original substrate 9A for a plurality of modules. Thereafter, terminals are provided and the original substrate 9
A is divided by a predetermined portion to obtain each interface module.

In this case, a V cut (split groove) 25 is formed on the original substrate 9A for each module unit. FIG.
, P1, P2, P3, P4, P5,... Indicate V cut positions for each module unit.

Then, the V cut 25 is divided into P1, P2, P
.. Provided at respective positions of P3, P4, P5,... And divided at these positions, an interface module as in the first embodiment can be obtained.

However, when the V cut 25 is changed to P1, P5, P
9 and P13, if divided at each of these positions, a quad interface module (# 1 to # 1)
3) is obtained.

If the position of the V-cut 25 is arbitrarily set, an n-type interface module can be formed. : Explanation of interface module ... see FIG. 7 FIG. 7 is a perspective view of a multiple (four in this example) type interface module divided at each of the positions P1, P5, P9 and P13. Show.

As shown, the multiple interface module includes module units MU1, MU2, M
U3 and MU4 are connected and integrated. In this case, in each module unit, the terminals 23 are provided only at both ends in the longitudinal direction of the printed circuit board 9. Therefore, the printed circuit boards of each module unit can be connected at a portion where no terminal is provided.

Each module unit MU1, MU
The configurations of 2, MU3, and MU4 are the same as in the first embodiment, and a description thereof will be omitted. (Other Embodiments) The embodiments have been described above, but the present invention can be implemented as follows.

(1) The V-cut position P1, shown in FIG.
P2, P3,... May be arbitrarily set depending on the application. Thereby, a multiple interface module in which a plurality of module units are connected is obtained.

(2) A low-pass filter having a configuration different from that of the above-described embodiment may be used.

[0066]

[Effects of the Invention] As described above, the present invention has the following effects. (1) Since an SMD chip-type transformer is used as the pulse transformer, a case like the conventional case does not need to be used. Therefore, there is no wasted space, and the interface module can be reduced in size and thickness accordingly.

(2) Since the GND pattern is provided on both the transmitting side and the receiving side in common (installation of a common GND pattern), a wide GND pattern can be formed even if the interface module is downsized. It is.

Therefore, common mode noise and the like can be greatly attenuated, and the number of terminals can be reduced by using a common GND pattern, whereby the size of the interface module can be reduced.

(3) Since a coil having the same height as the pulse transformer is mounted on the upper surface of the printed circuit board and a capacitor shorter than the pulse transformer is mounted on the lower surface of the printed circuit board. The interface module can be reduced in size and thickness.

(4) Since the low-pass filter of the transmitting unit and the low-pass filter of the receiving unit are mounted separately from each other with the center line XY in the longitudinal direction interposed therebetween, the Talk can be kept low.

(5) By arranging the pulse transformer and the low-pass filter in the longitudinal direction of the interface module, it is possible to sufficiently increase the distance between the input and output of both the transmitter and the receiver. Therefore, the impedance with respect to the common mode noise can be set high, and the radiation noise can be sufficiently reduced.

(6) As a whole, the interface module can be sufficiently reduced in size and thickness without deteriorating the characteristics. Further, the cost of the interface module can be reduced.

(7) Since the interface module is configured as described above, and terminals are provided only at both ends in the longitudinal direction of the printed board, the V
If the cutting position is set arbitrarily, multiple interface modules can be easily manufactured.

Further, by making the interface module a multiple type, it is possible to further reduce the size and to reduce the installation space of the interface module when used.

[Brief description of the drawings]

FIG. 1 is a diagram illustrating the principle of the present invention.

FIG. 2 is a diagram illustrating an interface circuit according to a first embodiment of the present invention.

FIG. 3 is a diagram illustrating component mounting on a printed circuit board according to the first embodiment of the present invention;

FIG. 4 is an internal structural view of the pulse transformer according to the first embodiment of the present invention;

FIG. 5 is a perspective view of the interface module according to the first embodiment of the present invention;

FIG. 6 is a diagram illustrating a process of manufacturing an interface module according to a second embodiment of the present invention.

FIG. 7 is a perspective view of an interface module according to a second embodiment of the present invention.

FIG. 8 is a diagram showing a conventional interface circuit.

FIG. 9 is a perspective view of a conventional interface module.

[Explanation of symbols]

 4, 5 Low-pass filter 6, 7 Pulse transformer 9 Printed circuit board 14 Common GND pattern

Claims (1)

(57) [Scope of request for utility model registration] 1. A transmitting unit and a receiving unit each being a transformer.
The transformer and the low-pass filter.
The filter is mounted on the printed circuit board (9) and integrated.
In the interface module described above, the longitudinal center line (XY) of the printed circuit board (9) is
On one side, the transformer (6) of the transmitter and a low-pass filter
(4) is arranged, and the other side of the center line is independent of the transmitting unit.
Stand-up transformer (7) and low-pass filter
(5) is arranged so that the transformers of the transmitting and receiving
-Pass filters are facing each other across the center line.
And the low-pass filters (4, 5) of the transmission / reception section.
Each consists of a coil part (12) and a capacitor part (13)
Then, on the transformer mounting surface side of the printed circuit board (9),
Only the coil part (12) of each low-pass filter is arranged,
On the other side, each low-pass filter sandwiches the printed circuit board.
The capacitor part (1
3) is arranged, and the printed circuit board (9 ) is located on the side of the capacitor mounting surface.
And a capacitor section of the transmitting section and a capacitor section of the receiving section.
And a common GND pattern (14) is provided between
A GND pattern (14) is connected to a capacitor section of the transmitting / receiving section.
(13) and a printed circuit board (9) on which the pair of transmission / reception units are mounted.
Interface module unit (MU1, MU
2, MU3 ...)
By connecting and integrating multiple
The feature is that it is a continuous type interface module.
Interface module to do.