JP2005341118A - Filter circuit, logic IC, multi-chip module, filter-mounted connector, transmission device and transmission system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce an induced current caused by external magnetic field noise generated from an adjacent circuit, suppress electromagnetic noise radiated from an inductor, and eliminate an increase in cost of an IC or a transmission device An object of the present invention is to provide an optical module, an IC, a connector, a transmission device, and a transmission system provided with the filter circuit.
In a filter circuit formed of a passive element such as a capacitive element and an inductor, the inductor forming the filter circuit has two windings having a central axis in the vertical direction on the same plane and different positions of the central axes. The two windings are connected so that the signal current flowing in each of them winds in a vortex in the opposite rotational direction, and the induced current caused by external magnetic field noise flows in the opposite direction. It is characterized by that.
[Selection] Figure 1

Description

  The present invention relates to a filter circuit that is less susceptible to signal waveform deterioration due to external magnetic field noise and that can reduce the generation of radiated electromagnetic noise, and particularly to an IC that transmits and receives high-speed signals, and the same. It is related with apparatuses, such as a communication apparatus comprised by these, a server, and communication IC.

  In recent years, the data transfer capacity between ICs and between transmission devices has increased rapidly, and accordingly, the data transmission rate per transmission line that electrically connects the driver circuit and receiver circuit that constitute the IC or transmission device. For example, in Japan, the speed is increased to 2.5 Gbit / second or 10 Gbit / second. Such an increase in data transmission speed causes an increase in skin effect and dielectric loss in the transmission path, and signal waveform deterioration becomes significant. In order to compensate for this signal waveform degradation, ICs and transmission devices with an equalizer circuit (high-pass filter circuit) to compensate for the effects of dielectric loss and conductor loss on the driver circuit, receiver circuit, or transmission line are produced. It is being done.

  In addition, increasing the data transfer rate causes an increase in high-frequency noise caused by electromagnetic interference between transmission lines, so a low-pass filter circuit for reducing high-frequency noise may be provided on the driver circuit, receiver circuit, or transmission line. Many.

  These filter circuits are generally composed of passive elements such as inductors and capacitive elements. The inductor constituting the filter circuit has a large current noise of several hundred μA because an induced current is induced in the direction of canceling the external magnetic field noise when the external magnetic field noise is incident on the central portion of the winding constituting the inductor. May be superimposed on the transmission signal, resulting in data loss or malfunction of the transmission device. Further, when a signal current is transmitted to the inductor, electromagnetic noise is radiated from the inductor, which may cause malfunction of other circuits and devices. As means for solving this problem, as shown in Patent Document 1, the entire IC including a circuit is shielded from an external circuit by a grounded conductor plate (shield case), thereby reducing the influence of external magnetic field noise, and There is a method for reducing radiated electromagnetic noise from a circuit.

JP-A-6-350280

  However, in the above method, it is possible to reduce the influence of noise from the outside of the ground conductor plate, but to reduce the induced current generated in the inductor due to electromagnetic noise radiated in the circuit shielded by the ground conductor plate. In addition, since it is necessary to provide a ground conductor plate separately from the IC, there is a problem that the cost of the IC and the transmission device is increased.

  Therefore, the present invention reduces the induced current caused by the external magnetic field noise generated from the adjacent circuit, which is the problem, suppresses the electromagnetic noise radiated from the inductor, and reduces the cost of the IC and the transmission device. It is an object of the present invention to provide a filter circuit that eliminates the increase, and an IC or a transmission device that includes the filter circuit.

  To achieve the above object, the present invention provides an inductor constituting a filter circuit such as a high-pass filter circuit having at least two windings having a central axis in the vertical direction of the same plane and different positions of the central axes. Each of the windings is formed so that the electromagnetic noises radiated from the windings have opposite signs to each other and are connected so as to cancel the induced current generated by the external magnetic field noise.

  Specifically, according to the present invention, in the inductor constituting the filter circuit, the first winding having one end as an input and the first winding are disposed in the same plane and the one end is connected to the first winding. And the second winding with the other end as an output, and the signal current flowing in each of the first winding and the second winding is wound in a vortex in the opposite rotation direction. The first winding and the second winding are connected so that the induced current generated in the first winding and the second winding flows in opposite directions.

  According to another aspect of the present invention, there is provided a transmission system configured by connecting a driver circuit and a receiver circuit through a transmission line, and the transmission circuit includes the filter circuit as a high-pass filter circuit.

  Further, the present invention is a transmission system configured by connecting a driver circuit and a receiver circuit through a transmission line, and the filter circuit is used as a high-pass filter circuit for compensating for waveform deterioration in the transmission line. A packaged filter IC is provided.

  In addition, the present invention is a logic IC characterized in that the filter circuit is provided in a logic IC having a logic circuit that performs logic operation processing.

  According to another aspect of the present invention, there is provided a multichip module in which a die having the filter circuit and a die having a logic circuit are mounted in a package.

  In addition, the present invention is a filter-mounted connector that is a connector for connecting between transmission lines and includes a filter chip in which the filter circuit is chipped.

  Further, the present invention is a transmission device for determining a transmission path of a transmission signal obtained from an optical module connected with an optical fiber by a switch IC and transmitting the transmission path in the optical module or the switch IC. The filter circuit is provided as a high-pass filter circuit.

  Further, the present invention provides a backplane in which a plurality of switch boards each mounted with an optical module to which optical fibers are connected and a switch IC for determining a transfer path for transmission signals obtained from the optical module are mounted on the backboard on which the transmission path is formed. A transmission device configured to be electrically connected by a connector, wherein the filter circuit is provided as a high-pass filter circuit in a transmission path in the optical module, the switch IC, or the backplane connector. .

  According to the present invention, the inductor constituting the filter circuit is formed by two windings having a central axis in the vertical direction on the same plane and having different positions of the central axes, and each winding is radiated from the winding. By winding the winding so that the electromagnetic noises have opposite signs to each other and canceling the induced current caused by the external magnetic field noise, not only the external magnetic field noise from relatively distant circuits and devices but also adjacent Similarly, the influence of the external magnetic field noise from the circuit can be reduced, and the radiation electromagnetic noise from the filter circuit can also be reduced.

  Further, according to the present invention, the filter circuit for reducing induced current and radiated electromagnetic noise does not need to use a ground conductor plate, and it is possible to suppress an increase in costs such as assembly costs for the IC and the transmission device. .

  Hereinafter, embodiments of a filter circuit, a logic IC, a multichip module, a filter-mounted connector, a transmission device, and a transmission system according to the present invention will be described with reference to the drawings.

[First Embodiment]
First, a filter circuit according to a first embodiment of the present invention will be described with reference to the drawings.

[Example 1]
First, a first embodiment of the filter circuit according to the present invention will be described.

  FIG. 1A is a configuration diagram showing a first embodiment of the high-pass filter circuit of the present invention fabricated on a Si substrate or the like, and FIG. 1B is a circuit diagram showing a first embodiment of the high-pass filter circuit of the present invention. is there. The high-pass filter circuit of the first embodiment includes two windings 102a and 102b each having a central axis in the vertical direction on the same plane and having different positions of the central axes, and one end is connected to the ground terminal 109. An inductor 101, a first resistance element 103 having one end connected to the inductor 101, a second resistance having one end connected to the first resistance element 103 and the other end connected to an input terminal 107 for inputting a signal from an external circuit An element 104, one end connected to the first resistance element 103, the other end connected to an output terminal 108 for outputting a signal to an external circuit, one end connected to the input terminal 107, and the other The capacitor 106 has an end connected to the output terminal 108. In particular, the inductor 101 cancels the induced current caused by the external magnetic field noise (about 10 GHz to 5 GHz or more) having the same vector in the opposite phase of the magnetic field radiated from each winding when the signal current is transmitted. Thus, it is characterized by comprising two windings 102a, 102b. That is, the two windings 102a and 102b are connected so that the signal current flowing through each of them is wound in a vortex in the opposite rotation direction, and the induced current caused by the external magnetic field noise flows in the opposite direction. Features.

  Furthermore, the two windings 102a and 102b constituting the inductor in the filter circuit of the present invention are configured so as to have the same inductance characteristics, thereby effectively canceling the induced current and radiated electromagnetic noise generated in each of them. Is possible.

  Further, the length of the transmission line constituting the inductor 101 is set to one fifth of the wavelength (about 3 to 6 cm) of the external magnetic field noise (about 10 GHz to 5 GHz) to be reduced or the band of the transmission signal (about 10 GHz to 1 GHz). The length is equal to or shorter than one fifth of the wavelength (about 3 to 30 cm). This is because the effect of external magnetic field noise is effectively reduced by reducing the phase difference of the induced current generated in each winding, and the phase difference of electromagnetic noise radiated from each winding is reduced. This is to reduce the total electromagnetic noise. In other words, by shortening the length of the transmission line constituting the inductor, it is possible to effectively reduce transmission waveform deterioration due to higher-frequency external magnetic field noise, and to reduce electromagnetic noise radiated from the inductor. Also grows.

  FIG. 2A shows the induced current amounts 201a and 201b generated in the respective windings 102a and 102b due to external magnetic field noise having a magnetic field strength with a maximum amplitude of about 1 Wb in the filter circuit shown in FIG. Induction current amount 201d generated in the case of a comparative example in which an inductor having an inductance value equivalent to that of inductor 101 shown in FIG. Where the horizontal axis represents time and the vertical axis represents the amount of current.

  In the inductor of the present invention, the induced current amount 201a generated in one winding 102a and the induced current amount 201b generated in the other winding 102b are opposite to each other, and the amplitudes thereof are of the same magnitude. Yes. That is, the total sum 201c of the induced currents generated in the two windings 102a and 102b can be made substantially zero. On the other hand, the maximum induced current amount 201d generated in the case of the comparative example in which the inductor is configured by one winding is 0.2 mA or more, so that the signal waveform deterioration is larger than that of the inductor configuration of the present invention.

  From the above, by using the inductor configuration of the present invention in the high-pass filter circuit formed by the capacitive element 106, the resistance elements 103 to 105 and the passive element of the inductor 101 according to the present invention, about 10 GHz to 5 GHz or more. It is possible to reduce the influence of transmission waveform deterioration of a transmission signal of about 10 GHz to 1 GHz or more due to external magnetic field noise.

  FIG. 2B shows the magnetic field strengths 202a and 202b at the central portions of the windings 102a and 102b when a signal current having a maximum amplitude of about 16 mA flows through the inductor 101 in the filter circuit shown in FIG. The magnetic field strength in the case of a comparative example in which the total sum 202c of the respective magnetic field strengths and an inductor having an inductance value equivalent to that of the inductor 101 shown in FIG. 202d is shown, the horizontal axis is time, and the vertical axis is magnetic field strength.

  In the inductor of the present invention, the magnetic field intensity 202a radiated from one winding 102a and the magnetic field intensity 202b radiated from the other winding 102b are opposite to each other, and their amplitudes are of the same magnitude. It has become. That is, the total sum 203c of the magnetic field intensity radiated from the two windings 102a and 102b can be made substantially zero. On the other hand, since the maximum magnetic field strength 202d generated in the case of the comparative example in which the inductor is configured by one winding is 100 Wb or more, the influence on the external circuit is larger than the inductor configuration of the present invention.

  From the above, by using the inductor configuration of the present invention, it is possible to reduce radiated electromagnetic noise and to reduce the influence on external circuits and devices.

  In the present embodiment, the Si substrate is shown as the substrate on which the high-pass filter circuit is mounted. However, the substrate is not particularly limited to the Si substrate, and even when a ceramic substrate or another semiconductor substrate such as GaAs is used. Similar effects can be obtained. In addition, a high-pass filter circuit that passes only a wide frequency band is shown as a filter circuit. However, by using the inductor configuration of the present invention, only a low-pass filter circuit that passes only a low-frequency band or a specific frequency band is used. The same effect can be obtained also in the band-pass filter circuit that passes.

  By configuring the inductor as described above, it is possible to reduce not only the external magnetic field noise from a relatively distant circuit or device but also the external magnetic field noise from an adjacent circuit, and from the high-pass filter circuit. Radiated electromagnetic noise can also be reduced. Further, the filter circuit for reducing induced current and radiated electromagnetic noise according to the present invention does not require the use of a ground conductor plate (shield case) described in Patent Document 1, and costs such as assembly costs for ICs and transmission devices. It is possible to suppress the increase in

[Example 2]
Next, a second embodiment of the filter circuit according to the present invention will be described with reference to FIG. FIG. 3 is a diagram illustrating a configuration of a second embodiment of the filter circuit when the capacitor element and the input / output terminal electrode in the first embodiment of the filter circuit illustrated in FIG. 1 are shared. In the filter circuit of FIG. 3, the difference from FIG. 1 is that the capacitive element 106 has a common input terminal 107 and one electrode for inputting a signal from an external circuit connected to the other end of the second resistance element 104. That is, the capacitor 106 a, the output terminal 108 that outputs a signal to an external circuit connected to the other end of the third resistor 105, and the capacitor 106 b that shares one electrode are used. Note that the other electrode of the capacitor 106 a and the other electrode of the capacitor 106 b are connected by a conductor 120. As a result, the two capacitive elements 106 a and 106 b are connected in series between the input terminal 107 and the output terminal 108. In this way, by sharing the electrodes constituting the capacitor element with each of the input / output terminals 107 and 108, the chip size can be reduced as compared with the filter circuit shown in FIG. Cost can be reduced, and an increase in the cost of the transmission apparatus can be suppressed.

[Example 3]
Next, another embodiment of the inductor used in the first and second embodiments of the filter circuit will be described with reference to FIG. FIG. 4 shows a configuration of another embodiment of an inductor that can shorten the length of the transmission path constituting the inductor. In the inductor shown in FIG. 4, two windings 301 a and 301 b having a central axis in the vertical direction on the same plane and having different positions of the central axes, and a magnetic element disposed at the center of each winding 301 a and 301 b. It consists of metals 302a and 302b. By arranging the magnetic metals 302a and 302b in the central portions of the windings 301a and 301b, the magnetic flux density passing through the central portion of the windings is increased. Therefore, the transmission path is shorter than that of an inductor in which no magnetic metal is disposed. Since the equivalent inductance value can be obtained by the length, it is possible to reduce the influence of higher-frequency external magnetic field noise and to increase the effect of reducing electromagnetic noise radiated from the inductor.

[Example 4]
Next, still another embodiment of the inductor used in the first and second embodiments of the filter circuit will be described with reference to FIG. FIG. 5 shows an embodiment in which the inductor in the filter circuit of FIGS. 1 and 3 is constituted by a plurality of layers of windings. The inductor of the present embodiment has a first winding 401 having one end as an input side (not shown) and a first winding 401 positioned in the vertical direction of the first winding 401 and having one end connected to the first winding 401. Two windings 402 and a third winding 403 that is located on the same plane as the first winding 401, has a central axis at a position different from the first winding 401, and has one end connected to the second winding 402. And a fourth winding 404 that is positioned in the vertical direction of the third winding 403, has one end connected to the third winding 403 and the other end as an output side (not shown). Here, the first winding 401 and the second winding 402 are configured such that the signal currents flowing through them each wind a vortex in the same rotation direction, and the third winding 403 and the fourth winding 404 flow through each. The signal current is configured to wind a vortex in the rotation direction opposite to the signal current flowing in the first winding 401 or the second winding 402, and the first winding 401 and the second winding 402 are caused by external magnetic field noise. The second winding 402 and the third winding 403 are connected so that the induced current generated and the induced current generated in the third winding 403 and the fourth winding 404 flow in opposite directions. When an inductor is configured by arranging two layers of windings in the horizontal direction in this way, the required number of layers of the substrate increases as compared with the case where the inductor is configured by one layer of winding. An equivalent inductance value can be obtained with a small mounting area. Further, in this embodiment, the inductor configuration in the case where the windings are formed in two layers is shown. However, the induced current caused by the external magnetic field noise is canceled out, and the total sum of the electromagnetic noises radiated from the respective windings becomes small. If the winding is configured as described above, the same effect can be obtained even in an inductor configured with three layers of windings or an inductor configured with four layers.

  As described above, by forming a filter circuit using an inductor configured by connecting a plurality of winding layers, the entire filter circuit can be mounted as compared with the filter circuit of the embodiment shown in FIGS. The area can be reduced.

[Example 5]
Next, a third embodiment of the filter circuit according to the present invention will be described with reference to FIG. FIG. 6 is a diagram showing an embodiment of the filter circuit of the present invention configured using chip coils, chip capacitors, and chip resistors as individual components. The filter circuit shown in the third embodiment has a chip coil 501 having one end connected to the ground terminal 508, a first chip resistor 502 having one end connected to the chip coil 501, and one end connected to an input terminal 506 for inputting a signal. A second chip resistor 503 having the other end connected to the first chip resistor 502, a third chip having one end connected to the output terminal 507 for outputting a signal waveform, and the other end connected to the first chip resistor 502. The resistor 504 includes a chip capacitor 505 having one end connected to the input terminal 506 and the other end connected to the output terminal 507. In particular, as shown in the first to fourth embodiments, the chip coil 501 is formed of two windings having a central axis in the vertical direction on the same plane and having different positions of the central axis. The flowing signal currents are configured so as to wind vortices in opposite rotation directions, and the induced currents generated in the respective windings due to external magnetic field noise are connected so as to flow in opposite directions. Thus, even when the filter circuit is configured using individual components, it is possible to reduce the influence of external magnetic field noise and reduce radiated electromagnetic noise.

[Second Embodiment]
Next, a transmission device (transmission system) comprising a driver circuit and a receiver circuit as a filter IC packaged with the high-pass filter circuit described in the first embodiment for compensating for waveform deterioration in a transmission line according to the present invention. A second embodiment applied to () will be described with reference to FIG. The transmission apparatus (transmission system) shown in FIG. 7 has a driver circuit 602 that transmits a transmission signal of about 10 GHz to 1 GHz or more to the transmission line 604, and about 10 GHz to 1 GHz or more that is transmitted through the transmission line 604. A receiver circuit 603 that receives a transmission signal, and a filter circuit (specifically, a high-pass filter circuit) that is provided in the transmission path 604 and that improves a transmission waveform deteriorated due to dielectric loss and skin effect in the transmission path 604 The packaged filter IC 601 and the transmission path 604 for transmitting a transmission signal are included. An example of the configuration of the driver circuit 602 and the receiver circuit 603 is shown in FIG. The driver circuit 1201 (602) includes a logical operation circuit 1202 that performs operation processing on data and an output buffer 1203 for transmitting data. The receiver circuit 1204 (603) includes an input buffer 1205 for receiving data, and a logical operation circuit 1206 that performs operation processing on the received data.

  The filter IC 601 is configured by an inductor that reduces the radiated electromagnetic noise described in the first embodiment and is hardly affected by external magnetic field noise of about 10 GHz to 5 GHz or more. In the second embodiment, the filter IC is shown as a package having lead wires, but a package such as a BGA or flip chip may be used. The data signal output from the driver circuit 602 to the transmission path 604 has a signal waveform with a deteriorated rise / fall characteristic due to the skin effect and dielectric loss in the transmission path 604. When the signal waveform with the deteriorated rising / falling characteristics is input to the filter IC 601, the filter IC 601 compensates the influence of the loss in the transmission line 604 and is shaped into a signal waveform with improved rising / falling characteristics. The shaped signal waveform is output from the filter IC 601 and transmitted to the receiver circuit 603 via the transmission path 604. The filter IC 601 using the filter circuit described in the first embodiment has little influence on other circuits and devices because it hardly radiates electromagnetic noise even when a signal current is transmitted. Since the influence of the induced current caused by the magnetic field noise radiated from the device can be reduced, the filter IC 601 can stably improve the transmission waveform.

  As described above, by configuring the transmission system using the filter IC packaged with the filter circuit (specifically, the high-pass filter circuit) according to the present invention, the electromagnetic noise radiated from the transmission system is hardly increased. In addition, since the influence of external magnetic field noise of about 10 GHz to 5 GHz or more can be reduced, it is possible to construct a transmission system capable of stably transmitting (operating) a transmission signal of about 10 GHz to 1 GHz or more.

[Third Embodiment]
Next, a third embodiment of a logic IC in which the filter circuit described in the first embodiment is mounted on a die mounted with a logic circuit that performs logical operation processing of signals according to the present invention and packaged will be described. This will be described with reference to FIG. The logic IC of the third embodiment includes a filter circuit 901 that compensates for a loss in a transmission line and shapes a transmission waveform, a logic circuit 902 that performs a logical operation process on a signal, the filter circuit 901, and the logic circuit 902. A die 903 that is mounted (formed), a package 904 that is packaged by mounting the die 903, and a bonding wire 905 that electrically connects the die 903 and the package 904 are formed. Note that the filter circuit 901 and the logic circuit 902 need to be built and mounted on the same die 903. Therefore, it is necessary to add a manufacturing process (capacitance or resistance) peculiar to the filter circuit to the process of manufacturing the logic circuit. The filter circuit 901 includes an inductor that reduces the radiated electromagnetic noise described in the first embodiment and is less susceptible to external magnetic field noise. When a signal is transmitted from the external circuit to the logic IC, the transmitted signal reaches the filter circuit 901 via the bonding wire 905. The signal reaching the filter circuit 901 is waveform-shaped by the filter circuit 901 and transmitted to the logic circuit 902. At this time, even when a signal current is transmitted in the filter circuit 901, almost no electromagnetic noise is radiated, and the influence of the induced current caused by magnetic field noise radiated from an adjacent circuit such as the logic circuit 902 is reduced. it can.

  As described above, by forming the filter circuit according to the present invention on the die, in the filter circuit, it is possible to reduce the influence of magnetic field noise radiated from adjacent circuits as well as relatively far-field external magnetic field noise, In addition, since the radiation electromagnetic noise from the filter circuit can be reduced, it is possible to form a logic IC that reduces data loss and occurrence of errors during logic operation processing.

  In the third embodiment, the method of electrically connecting the die and the package by the bonding wire is shown. However, if the method of electrically connecting the die and the package is used, for example, the die is a flip chip. Similar effects can be obtained by mounting on a substrate and connecting to a package.

[Fourth Embodiment]
Next, a fourth example of a multichip module according to the present invention in which a plurality of dies such as a die mounted with a filter circuit and a logic circuit described in the first embodiment are mixedly mounted in the same package. The embodiment will be described with reference to FIG. The multichip module of the fourth embodiment includes a filter circuit die 1001 mounted with a filter circuit (specifically, a high-pass filter circuit) that compensates for a loss in the transmission path, as described in the first embodiment. A logic circuit die 1002 having a logic circuit for logically processing signals, a filter circuit die 1001 and a package 1003 having the logic circuit die 1002 mounted thereon, and bonding between the dies or between the die and the package, for example, bonding It consists of a wire 1004. The fourth embodiment is different from the third embodiment in that the die 1001 mounting the filter circuit is separated from the die 1002 mounting the logic circuit. The filter circuit mounted on the filter circuit die 1001 is characterized by being formed of an inductor that reduces radiated electromagnetic noise and is less susceptible to external magnetic field noise. As described above, by combining the filter circuit die and the logic circuit die on which the filter circuit according to the present invention is mounted to constitute a multichip module, not only the relatively far-field external magnetic field noise but also, for example, the same The effect of magnetic field noise radiated from adjacent circuits such as the logic circuit mounted on the package can be reduced, and the radiated electromagnetic noise from the filter circuit can be reduced, reducing the occurrence of data loss and errors during logic operation processing. A multichip module can be formed. In the case of the fourth embodiment, it is not necessary to newly create a logic circuit by mounting the filter circuit and the logic circuit on different dies. In such a case, the manufacturing cost is higher than that of the logic IC of the third embodiment shown in FIG. Can be reduced.

  In the fourth embodiment, a method of electrically connecting dies or between a die and a package by a bonding wire is shown. However, any method for electrically connecting dies or between a die and a package may be used. For example, the same effect can be obtained by a method in which a die is mounted on a substrate as a flip chip and connected to a die or a package.

  As described above, in the third and fourth embodiments, the filter circuit described in the first embodiment (specifically, a high-pass filter circuit) is included in a logic IC having a logic circuit that performs logic operation processing. It is equipped with.

[Fifth Embodiment]
Next, a fifth embodiment of the filter-mounted connector according to the present invention in which the filter chip packaged with the filter circuit described in the first embodiment is mounted on the backplane connector will be described with reference to FIG. To do. The filter-mounted connector according to the fifth embodiment includes a backplane connector 1101 that electrically connects two boards, and a filter circuit for compensating for the loss in the transmission line described in the first embodiment ( Specifically, a high-pass filter circuit) is mounted, and the filter chip 1102 is connected to a transmission line in the backplane connector 1101. A transmission signal of about 10 GHz to 1 GHz or higher, which is output from an external circuit and reaches the motherboard side pin 1103 or the daughter board side pin 1104 via a substrate (not shown), is transmitted to the filter chip 1102 and transmitted by the filter chip 1102. Compensates for path loss and shapes the transmission waveform. The shaped transmission signal is output to another external circuit (not shown) via the daughter board side pin 1104 or the motherboard side pin 1103. At this time, the filter chip 1102 equipped with the filter circuit according to the present invention hardly radiates electromagnetic noise even when a signal current is transmitted, and therefore has little influence on other circuits and devices. Since the influence of the induced current caused by the magnetic field noise radiated from the apparatus can be reduced, it is possible to stably obtain the improvement effect of the transmission waveform.

  In the fifth embodiment, an embodiment in which the filter chip 1102 is applied to the backplane connector 1101 has been described. However, for example, the filter chip 1102 may be applied to a connector used at an end portion of a cable that connects substrates and devices. Good.

  As described above, by configuring the filter-mounted connector using the filter circuit according to the present invention, the electromagnetic noise radiated from the connector is hardly increased and the influence of the external magnetic field noise can be reduced. An operating filter-mounted connector can be manufactured, and since it is not necessary to mount the filter circuit in the IC or on the substrate, the IC or the substrate can be reduced in size.

[Sixth Embodiment]
Next, a sixth embodiment of an apparatus for transmitting and receiving a high-speed signal using the filter circuit described in the first embodiment according to the present invention will be described with reference to FIG. FIG. 11 shows a transmission apparatus (transmission system) for switching a transfer path of a transmission signal sent by an optical fiber, and a plurality of optical modules for converting a transmission signal of about 10 GHz to 1 GHz or more into an optical-electrical signal. 702, a plurality of optical fibers 701 that transmit optical signals, a plurality of switch ICs 705 that determine transfer paths of transmission signals, a plurality of optical modules 702, a plurality of switch boards 703 on which the switch ICs 705 are mounted, and a plurality of A back board 704 for transmitting a signal between the switch boards 703 and a plurality of back plane connectors 706 for electrically connecting each of the plurality of switch boards 703 and the back board 704. That is, the transmission apparatus (transmission system) is a switch board on which a plurality of optical modules 702 connected with optical fibers 701 and a switch IC 705 for switching transfer paths of transmission signals from the optical module 702 of about 10 GHz to 1 GHz or more are mounted. A plurality of (many) 703 are connected and mounted on a backboard 704 by a backplane connector 706 in a blade shape.

  The filter circuit according to the present invention is applied to the optical module 702, the switch IC 705, or the backplane connector 706. Since the optical module 702 and the switch IC 705 are configured to include a driver circuit 602 and a receiver circuit 603 as shown in FIG. 7, a filter circuit (see FIG. 7) is provided between the driver circuit 602 and the receiver circuit 603. It is possible to provide a filter IC) 601. Also, the filter chip 1102 can be inserted into the backplane connector 706 as in the fifth embodiment shown in FIG.

  In this transmission apparatus, an optical signal received from the optical fiber 701 is converted into an electrical signal of about 10 GHz to 1 GHz or more by an optical module 702 to which the optical fiber 701 is connected. Further, the converted electric signal is transmitted from the optical module 702 to the switch IC 705, and the transfer path of the electric signal is determined in the switch IC 705. At this time, the electrical signal is transferred to the optical module 702 on the other switch board 703 via the other optical module 702 on the switch board 703 or the back board 704 according to the determined transfer path. The transferred electrical signal is converted from an electrical signal to an optical signal by the optical module 702, and the optical signal is transmitted to another transmission apparatus through the optical fiber 701 connected to the optical module 702.

  As described above, by configuring the transmission device using the optical module, switch IC, and connector to which the filter circuit according to the present invention is applied, it is possible to reduce the influence of external magnetic field noise and to prevent data loss or malfunction of the transmission device. It is possible to reduce the generation of the electromagnetic noise radiated from the apparatus. A specific example of such a transmission apparatus is not limited to this, but includes, for example, a switch board, a router, a server, a computer, and a computer peripheral device.

FIG. 1 is a schematic configuration diagram and a circuit diagram showing Example 1 of the filter circuit according to the first embodiment of the present invention. FIG. 2 is a diagram showing the amount of induced current generated in the windings constituting the inductor and the strength of the magnetic field radiated from the windings. FIG. 3 is a schematic configuration diagram illustrating Example 2 of the filter circuit according to the first embodiment of the invention. FIG. 4 is a schematic diagram showing the configuration of an inductor that can be used in the filter circuit according to the present invention to make the length of the transmission line shorter. FIG. 5 is a schematic diagram showing a case where an inductor is constituted by four windings used in the filter circuit according to the present invention. FIG. 6 is a schematic configuration diagram illustrating Example 3 including chip coils, chip capacitors, and chip resistors as individual components of the filter circuit according to the first embodiment of the present invention. FIG. 7 is a diagram showing a transmission system to which a filter IC in which a filter circuit is made into an IC package, which is a second embodiment of the present invention, is applied. FIG. 8 is a perspective view showing a logic IC in which a filter circuit is mounted and packaged on a die on which a logic circuit for logically processing signals is mounted according to a third embodiment of the present invention. FIG. 9 is a perspective view showing a multichip module according to a fourth embodiment of the present invention, in which a plurality of dies such as a die equipped with a filter circuit and a die equipped with a logic circuit are mixedly mounted in the same package. It is. FIG. 10 is a perspective view showing a filter-mounted connector in which a filter chip in which a filter circuit is packaged is mounted on a backplane connector according to a fifth embodiment of the present invention. FIG. 11 is a perspective view showing a transmission apparatus for transmitting and receiving a high-speed signal using a filter circuit according to a sixth embodiment of the present invention. It is a block diagram which shows one Example of the driver circuit and receiver circuit which are used for the transmission apparatus (transmission system) which concerns on this invention.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 101 ... Inductor, 102a, 102b ... Winding, 103, 104, 105 ... Resistance element, 106, 106a, 106b ... Capacitance element, 107 ... Input terminal, 108 ... Output terminal, 109 ... Ground terminal, 201a, 201b, 201c, 201d: induction current amount, 202a, 202b, 202c, 202d ... radiation electromagnetic noise intensity, 301a, 301b ... winding, 302a, 302b ... magnetic material, 401, 402, 403, 404 ... winding, 501 ... chip coil, 502 , 503, 504... Chip resistor, 505... Chip capacitor, 506... Input terminal, 507... Output terminal, 508 .. Ground terminal, 601. Filter IC, 602, 1201. Path, 901... Filter circuit, 902... Logic circuit, 90 Die, 904 ... Package, 905 ... Bonding wire, 1001 ... Filter circuit die, 1002 ... Logic circuit die, 1003 ... Package, 1004 ... Bonding wire, 1101 ... Backplane connector, 1102 ... Filter chip, 1103 ... Motherboard side pin, DESCRIPTION OF SYMBOLS 1104 ... Daughter board side pin, 701 ... Optical fiber, 702 ... Optical module, 703 ... Switch board (blade board), 704 ... Back board, 705 ... Switch IC, 706 ... Connector.

Claims (11)

A filter circuit formed of passive elements such as an inductor, a capacitive element, and a resistive element,
The inductor is composed of at least two windings having a central axis in the vertical direction on the same plane and having different positions of the central axes, and the at least two windings have rotational directions in which signal currents flowing in the opposite directions are opposite to each other. A filter circuit characterized by being formed so as to wind a vortex and connected so that an induced current caused by external magnetic field noise flows in the opposite direction.   2. The filter circuit according to claim 1, further comprising a magnetic body at a central portion of the at least two windings. A filter circuit formed of passive elements such as an inductor, a capacitive element, and a resistive element,
The inductor is positioned on the same plane as the first winding, the second winding that is positioned in the vertical direction of the first winding, one end of which is connected to the first winding, and the first winding. A third winding having a central axis at a position different from that of the first winding, one end connected to the second winding, and a vertical direction of the third winding, and one end at the third winding The first winding and the second winding are formed such that the signal currents flowing through them each wind a vortex in the same rotational direction, and the third winding and the second winding The four windings are formed so that the signal current flowing in each of them winds in a vortex in the rotation direction opposite to the signal current flowing in the first winding or the second winding, and the first winding is caused by external magnetic field noise. Induced current generated in the wire and the second winding, and the third winding and the fourth winding. Filter circuit characterized in that Jill induced current is formed by connecting the third winding and the second winding to flow in the opposite direction. A filter circuit formed using a chip coil, a chip capacitor and a chip resistor as individual components,
The chip coil is formed of at least two windings having a central axis in the vertical direction on the same plane and having different positions of the central axis, and the at least two windings have rotational directions in which signal currents flowing in opposite directions are opposite to each other. The filter circuit is formed so as to be wound so that an induced current generated in each winding due to external magnetic field noise flows in a reverse direction. A transmission system configured by connecting a driver circuit and a receiver circuit via a transmission line,
A transmission system comprising the filter circuit according to claim 1 as a high-pass filter circuit in the transmission line. A transmission system configured by connecting a driver circuit and a receiver circuit via a transmission line,
5. A transmission characterized in that the transmission line includes a filter IC in which the filter circuit according to claim 1 is packaged as a high-pass filter circuit that compensates for waveform deterioration in the transmission line. system.   5. A logic IC comprising the filter circuit according to claim 1 in a logic IC having a logic circuit that performs logic operation processing.   5. A multi-chip module comprising a die mounted with the filter circuit according to claim 1 and a die mounted with a logic circuit mounted in a package.   5. A filter-mounted connector for connecting between transmission lines, comprising a filter chip formed by chipping the filter circuit according to claim 1. A transmission device for determining a transmission path of a transmission signal obtained from an optical module connected with an optical fiber by a switch IC and transmitting the transmission path,
5. A transmission apparatus comprising the filter circuit according to claim 1 as a high-pass filter circuit in a transmission path in the optical module or the switch IC. A plurality of switch boards mounted with an optical module connected to an optical fiber and a switch IC for determining a transfer path of a transmission signal obtained from the optical module are electrically connected to the back board on which the transmission path is formed with a backplane connector. A transmission device configured as follows:
5. A transmission apparatus comprising the filter circuit according to claim 1 as a high-pass filter circuit in a transmission path in the optical module, the switch IC, or the backplane connector.

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