U.S. patent application number 16/067219 was filed with the patent office on 2019-01-10 for cable.
This patent application is currently assigned to Sony Corporation. The applicant listed for this patent is SONY CORPORATION. Invention is credited to Makoto MAKISHIMA, Tomomichi MURAKAMI, Satoru TSUBOI, Yoshitaka YOSHINO.
Application Number | 20190013630 16/067219 |
Document ID | / |
Family ID | 59311068 |
Filed Date | 2019-01-10 |
![](/patent/app/20190013630/US20190013630A1-20190110-D00000.png)
![](/patent/app/20190013630/US20190013630A1-20190110-D00001.png)
![](/patent/app/20190013630/US20190013630A1-20190110-D00002.png)
![](/patent/app/20190013630/US20190013630A1-20190110-D00003.png)
![](/patent/app/20190013630/US20190013630A1-20190110-D00004.png)
![](/patent/app/20190013630/US20190013630A1-20190110-D00005.png)
![](/patent/app/20190013630/US20190013630A1-20190110-D00006.png)
![](/patent/app/20190013630/US20190013630A1-20190110-D00007.png)
![](/patent/app/20190013630/US20190013630A1-20190110-D00008.png)
United States Patent
Application |
20190013630 |
Kind Code |
A1 |
YOSHINO; Yoshitaka ; et
al. |
January 10, 2019 |
CABLE
Abstract
A cable includes a cable part including at least one set of
signal cables for differential transmission, a ground cable, and a
power cable, and a first connector and a second connector arranged
at both ends of the cable part. At least one of the first connector
and the second connector has a common-mode choke coil connected to
the ground cable and the power cable.
Inventors: |
YOSHINO; Yoshitaka; (Tokyo,
JP) ; TSUBOI; Satoru; (Kanagawa, JP) ;
MURAKAMI; Tomomichi; (Tokyo, JP) ; MAKISHIMA;
Makoto; (Kanagawa, JP) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
SONY CORPORATION |
Tokyo |
|
JP |
|
|
Assignee: |
Sony Corporation
Tokyo
JP
|
Family ID: |
59311068 |
Appl. No.: |
16/067219 |
Filed: |
October 21, 2016 |
PCT Filed: |
October 21, 2016 |
PCT NO: |
PCT/JP2016/004655 |
371 Date: |
June 29, 2018 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
H01B 9/003 20130101;
H01R 13/719 20130101; H01R 13/6633 20130101; H05K 9/0098 20130101;
H01R 13/6581 20130101; H03H 7/0115 20130101; H01R 2107/00 20130101;
H01B 11/1083 20130101; H01R 24/60 20130101; H01R 13/6625 20130101;
H01R 13/6598 20130101 |
International
Class: |
H01R 13/719 20060101
H01R013/719; H01B 9/00 20060101 H01B009/00; H03H 7/01 20060101
H03H007/01; H05K 9/00 20060101 H05K009/00; H01R 13/6581 20060101
H01R013/6581; H01R 13/6598 20060101 H01R013/6598 |
Foreign Application Data
Date |
Code |
Application Number |
Jan 15, 2016 |
JP |
2016-005896 |
Claims
1. A cable comprising: a cable part including at least one set of
signal cables for differential transmission, a ground cable, and a
power cable; and a first connector and a second connector arranged
at both ends of the cable part, wherein at least one of the first
connector and the second connector has a common-mode choke coil
connected to the ground cable and the power cable.
2. The cable according to claim 1, wherein the common-mode choke
coil is effective in noise removal not only in a common mode but
also in a differential mode.
3. The cable according to claim 1, wherein a connector having the
common-mode choke coil further has a condenser for noise removal
which is placed between the ground cable and the power cable.
4. The cable according to claim 1, wherein a connector having the
common-mode choke coil further has a substrate having the
common-mode choke coil mounted thereon and an insulating resin
layer covering the substrate.
5. The cable according to claim 4, wherein the connector having the
common-mode choke coil further has an electromagnetic wave
shielding layer covering the insulating resin layer.
6. The cable according to claim 5, wherein the electromagnetic wave
shielding layer contains carbon or ferrite.
7. The cable according to claim 5, wherein the one set of signal
cables is installed such that the one set of signal cables does not
come into contact with the electromagnetic wave shielding
layer.
8. The cable according to claim 7, wherein, on a side of the
connector having the electromagnetic wave shielding layer, one end
of the one set of signal cables is shorter than one end of the
ground cable and the power cable.
9. The cable according to claim 5, wherein, on a side of the
connector having the electromagnetic wave shielding layer, one end
of the one set of signal cables is covered with an insulating
covering material.
10. The cable according to claim 1, wherein one of the first
connector and the second connector has the common-mode choke coil
connected to the ground cable and the power cable, and the other of
them has a ferrite bead arranged in the ground cable and the power
cable.
11. The cable according to claim 1, wherein at least one of the
first connector and the second connector further has a common-mode
choke coil connected to the one set of signal cables.
Description
TECHNICAL FIELD
[0001] The present disclosure relates to a cable, such as USB
(Universal Serial Bus), that conforms to the standard for
differential serial transmission.
BACKGROUND ART
[0002] The cable (USB cable) conforming to the USB standard
includes a pair of cables for differential transmission, a power
cable, and a ground cable (called GND cable hereinafter). The USB
cable has countermeasures against noise detrimental to the
differential transmission cables. An example of this is found in
PTL 1 which discloses a method of suppressing radiation noise by
arranging one transmission transformer near one terminal of the
paired differential transmission line.
CITATION LIST
Patent Literature
[0003] [PTL 1]
[0004] Japanese Patent No. 3306044
SUMMARY
Technical Problem
[0005] The USB cable is occasionally used not only for data
transmission but also for power supply from a power supply unit
(such as battery charger and personal computer (called "PC"
hereinafter), etc.) to various devices (such as smart phone and
tablet) by connecting the power supply unit and the devices. Under
such a situation, the absence of an effective anti-noise measure in
the power supply unit sometimes makes the power-receiving device
suffer noise originating from the power supply unit.
[0006] It is an object of the present disclosure to provide a cable
capable of noise suppression.
Solution to Problem
[0007] The present disclosure discloses a cable including a cable
part having at least one set of signal cables for differential
transmission, a ground cable, and a power cable; and a first
connector and a second connector arranged at both ends of the cable
part, in which at least one of the first connector and the second
connector has a common-mode choke coil connected to the ground
cable and the power cable.
Advantageous Effect of Invention
[0008] As mentioned above, according to the present disclosure, the
cable disclosed therein has a ground cable and a power cable each
connected to a common-mode choke coil, so that it is capable of
noise suppression.
BRIEF DESCRIPTION OF DRAWINGS
[0009] FIG. 1 is a schematic diagram of a USB cable pertaining to
one embodiment of the present disclosure.
[0010] FIG. 2 is a sectional view of a cable part taken along a
line II-II in FIG. 1.
[0011] FIG. 3A is a sectional view of a USB connector taken along a
line IIIA-IIIA in FIG. 1. FIG. 3B is a sectional view of the USB
connector taken along a line IIIB-IIIB in FIG. 1.
[0012] FIG. 4A is a sectional view of the USB connector taken along
a line IVA-IVA in FIG. 3A. FIG. 4B is a sectional view of a
connector taken along a line IVB-IVB in FIG. 3A.
[0013] FIG. 5 is a connection diagram of the USB cable pertaining
to one embodiment of the present disclosure.
[0014] FIG. 6 is a graph depicting impedance-frequency
characteristics of a common-mode choke coil for signals.
[0015] FIG. 7 is a graph depicting impedance-frequency
characteristics of a common-mode choke coil for power supply.
[0016] FIG. 8 is a graph depicting frequency characteristics for
the loss that occurs as a result of inserting a capacitor for noise
removal.
[0017] FIG. 9 is a graph depicting frequency characteristics for a
loss factor of a molded part.
[0018] FIG. 10 is a sectional view of a USB connector pertaining to
a modified embodiment of the present disclosure.
DESCRIPTION OF EMBODIMENT
[0019] The following describes an embodiment of the present
disclosure with reference to the accompanying drawings. The
description proceeds in the following order.
1. Constitution of USB cable 2. Method for producing USB cable 3.
Modified embodiment
1. Constitution of USB Cable
[0020] A USB cable pertaining to one embodiment of the present
disclosure is constructed as depicted in FIG. 1. The USB cable
includes a cable part 11, a standard USB connector (Type-A) 21
connected to one end of the cable part 11, and a micro (abbreviated
as "p" hereinafter) USB connector (Type-A) 31 connected to the
other end of the cable part 11. The standard USB connector (simply
called "USB connector" hereinafter) 21 is connected to a host side
(such as PC, battery charger (so-called AC adapter), etc.) and the
pUSB connector 31 is connected to a device side (such as smartphone
and tablet).
[0021] (Cable Part)
[0022] The cable part 11, depicted in FIG. 2, includes four cables
(electric cable) having one pair of signal cables 12a and 12b for
differential-mode transmission (differential mode), a power cable
13a, and a GND cable 13b. Each of these cables 12a, 12b, 13a, and
13b includes a conductor 14 as a core and an insulating coating 15
surrounding it.
[0023] The conductor 14 may be either a solid wire of copper or a
stranded wire of copper. In a case where the stranded wire is used,
to ensure the tensile strength and the flexibility of the wire, the
stranded wire may be one which is formed by twisting the core of
copper wires and the covering thread of aramide fiber, with a layer
of insulating resin covering them. This structure is applicable to
any of the signal cables 12a and 12b, the power cable 13a, and the
GND cable 13b. The signal cables 12a and 12b may be in the form of
twisted pair, for example.
[0024] The signal cables 12a and 12b are covered with a metal sheet
16, which may be a copper or aluminum foil placed thereon or a
copper or aluminum ribbon wound around them, with both structures
combined together optionally. The metal sheet 16, which is not
earthed, has the advantage of being free from the problem of
bigtail that results from using a braided wire.
[0025] A covering layer 17 covers the signal cables 12a and 12b
which are covered with the metal sheet 16, the power cable 13a, and
the GND cable 13b. The covering layer 17 has its inside filled with
a resin containing magnetic powder 18. The resin containing
magnetic powder 18 exists in the space between the inner surface of
the covering layer 17 and the bunch of the signal cables 12a and
12b, the power cable 13a, and the GND cable 13b. The signal cables
12a and 12b, which are covered with the metal sheet 16, is able to
transmit signals without being affected by the resin containing
magnetic powder 18.
[0026] As the insulating coating 15 covering the conductors 14 and
the covering layer 17, a variety of materials are used. For
example, materials such as polyethylene, polypropylene, PVC
(polyvinyl chloride), and elastomer may be used.
[0027] The resin containing magnetic powder 18 is a mixture of a
synthetic resin and a magnetic powder. The synthetic resin
includes, for example, styrene elastomer. A synthetic resin such as
olefin elastomer and PVC other than styrene elastomer may be used.
The magnetic powder includes, for example, Ni--Zn ferrite. As the
magnetic powder, Ni--Cu--Zn ferrite, Mn--Zn ferrite, and soft
magnetic metal may be used, and other magnetic powder based on such
metals as copper, magnesium, lithium, zinc, iron (e.g., permalloy),
and cobalt may also be used.
[0028] The resin containing magnetic powder 18 preferably contains
ferrite in an amount equal to or more than 70 wt % and equal to or
less than 95 wt %, typically 89 wt %. Ferrite in an amount equal to
or more than 70 wt % is particularly effective in absorption of
high-frequency noise. On the other hand, ferrite in an amount equal
to or less than 95 wt % is effective in reducing adverse effects on
moldability, flexibility, and mechanical properties such as tensile
strength.
[0029] (Connector)
[0030] An example of the constitution of the USB connector 21 will
be described below with reference to FIGS. 3A 3B, 4A, and 4B. The
USB connector 21 includes a printed circuit board 22, a plug 23
supported on the printed circuit board 22, and a molded part 24
that covers the printed circuit board 22 supporting the plug 23.
The molded part 24 has the plug 23 protruding from one end thereof
and also has the cable part 11 derived from the other end
thereof.
[0031] The printed circuit board 22 has on one side thereof
terminals 25a and 25d, a common-mode choke coil (called common-mode
filter occasionally) 26 for power source, and the capacitor
(condenser) for noise removal (not depicted). The terminals 25a and
25d have the power cable 13a and the GND cable 13b connected
thereto respectively. The printed circuit board 22 has on the other
side thereof terminals 25b and 25c and a common-mode choke coil 27.
The terminals 25b and 25c are connected to the signal cables 12a
and 12b respectively.
[0032] The printed circuit board 22 has terminals 28a, 28b, 28c,
and 28d, and the terminals 28a, 28b, 28c, and 28d extend from the
substantially center to one end thereof. The plug 23 is supported
on the printed circuit board 22 such that it covers that part of
the printed circuit board 22 on which the terminals 28a, 28b, 28b,
and 28c are formed.
[0033] The molded part 24 includes an insulating resin layer 24a
and an electromagnetic wave shielding layer 24b, with the former
functioning as an inner molded part that encloses the surrounding
of the printed circuit board 22 and the latter functioning as an
outer molded part that covers the surrounding of the insulating
resin layer 24a. The insulating resin layer 24a includes an
insulating polymeric resin such as polypropylene, and the
electromagnetic wave shielding layer 24b includes carbon or ferrite
and a polymeric resin capable of shielding, such as absorbing or
reflecting, electromagnetic waves.
[0034] The cable part 11 has on one end thereof the signal cables
12a and 12b, the power cable 13a, and the GND cable 13b, with their
parts exposed without being covered by the covering layer 17 and
the resin containing magnetic powder 18 (these parts will be called
"uncovered parts" hereinafter). The uncovered parts of the cables
12a, 12b, 13a, and 13b are embedded in the insulating resin layer
24a.
[0035] The signal cables 12a and 12b have the uncovered parts at
one end thereof formed such that they are shorter than the
uncovered parts at one end of the power cable 13a and the GND cable
13b so that they do not come into contact with the electromagnetic
wave shielding layer 24b. This prevents signals from attenuating
due to contact of the electromagnetic wave shielding layer 24b with
the uncovered parts of the signal cables 12a and 12b. In order to
avoid contact between the electromagnetic wave shielding layer 24b
and the uncovered parts of the signal cables 12a and 12b, it is
desirable that the uncovered parts of the signal cables 12a and 12b
extend almost straight toward their respective terminals 25b and
25c.
[0036] The signal cables 12a and 12b may be constructed such that
the uncovered parts thereof are covered with an insulating covering
material 12c. This avoids contact between the electromagnetic wave
shielding layer 24b and the uncovered parts of the signal cables
12a and 12b. The insulating covering material 12c includes, for
example, an insulating tube, an insulating tape, an insulating
film, a heat-shrinkable tube, a heat-shrinkable tape, and a
heat-shrinkable film.
[0037] The pUSB connector 31 is constructed in the similar way to
the USB connector 21 mentioned above, such that the printed circuit
board is covered with the molded part.
[0038] As depicted in FIG. 5, for example, the USB connector 21 is
connected to the receptacle of a host 20, and the iUSB connector 31
is connected to the receptacle of a portable terminal 30. The
terminals 28a, 28b, 28c, and 28d of the USB connector 21 are a
source terminal (pin 1: Vbus terminal), a data terminal (pin 2:
D-terminal), a data terminal (pin 3: D+terminal), and a ground
terminal (pin 4: GND terminal), respectively. Terminals 36a, 36b,
36c, 36d, and 36e of the .mu.USB connector 31 are a source terminal
(pin 1: Vbus terminal), a data terminal (pin 2: D-terminal), a data
terminal (pin3: D+terminal), an identifying terminal (pin4: ID
terminal), and a ground terminal (pin 5: GND terminal),
respectively.
[0039] The USB connector 21 has its terminals 28b and 28c connected
to respective two terminals on one side of the common-mode choke
coil 27. Two terminals on the other side of the common-mode choke
coil 27 are connected to two terminals on one side of a common-mode
choke coil 32 arranged in the pUSB connector 31 through the signal
cables 12a and 12b. Two terminals on the other side of the
common-mode choke coil 32 are connected to the terminals 36b and
36c.
[0040] The USB connector 21 has its terminals 28a and 28d connected
to two terminals on one side of the common-mode choke coil 26. A
capacitor (condenser) 29 for noise removal is inserted between two
terminals on the other side of the common-mode choke coil 26. The
two terminals on the other side of the common-mode choke coil 26
are connected to the terminals 36a and 36e of the pUSB connector 31
through the power cable 13a and the GND cable 13b. The pUSB
connector 31 includes ferrite beads 33 and 34. The ferrite beads 33
and 34 are arranged respectively in the power cable 13a and the GND
cable 13b in the pUSB connector 31. A resistor 35 for
identification is connected to the terminals 36d and 36e.
[0041] The signal cables 12a and 12b have two common-mode choke
coils 27 and 32 inserted therein; however, one of them may be
omitted. The pUSB connector 31 may be modified in constitution such
that the power cable 13a and the GND cable 13b are connected to the
common-mode choke coils in place of the ferrite beads 33 and 34.
Incidentally, in the case of the USB connector conforming to the
Type-C standard, both cables connected to the host side and the
device side allow power supply. In this case it is desirable to
provide both connector sides with the common-mode choke coils
connected to the power cable 13a and the GND cable 13b.
[0042] Each of the common-mode choke coils 26, 27, and 32 includes
one common core and two coils wound thereon in the opposite
directions. The common-mode choke coils 27 and 32 are inserted into
each of the signal cables 12a and 12b as two data lines. The
common-mode choke coil 26 is inserted into each of cables including
the power cable 13a and the GND cable 13b as two power supply
lines.
[0043] The common-mode choke coils 26, 27, and 32 permit the
passage of signal currents in differential mode and remove noise
current in a common mode. That is, in the case of the differential
mode, the two coils cause the currents to flow in the opposite
directions, so that they do not function as an inductor. By
contrast, in the case of the common mode, the two coils cause the
currents to flow in the same direction, so that they function as
the inductor. Being in the common mode, noise can be removed. In
fact, however, the inductance component does not become null
because part of a magnetic flux occurring in each coil becomes a
leakage flux. Consequently, there is an instance in which this
inductance component is non-negligible in a region where a signal
frequency is extremely high. Moreover, it is possible to remove
noise by means of the capacitor 29 for noise removal. It is also
possible to remove high-frequency noise by means of the ferrite
beads 33 and 34.
[0044] The foregoing enhanced performance on noise reduction in
power transmission prevents the portable terminal 30 from
decreasing in a reception level due to noise occurring in the
battery charger and PC to which the USB connector 21 is
connected.
[0045] Impedance-frequency characteristics of the common-mode choke
coil 27 (or 32) for signals is depicted in FIG. 6. A solid line 41
denotes impedance-frequency characteristics in the common mode. A
broken line 42 denotes impedance-frequency characteristics in the
differential mode. It is to be noted, for example, that the
impedance in the differential mode is low in the neighborhood of
100 MHz. This suggests that the effect on signal transmission is
insignificant.
[0046] Impedance-frequency characteristics of the common-mode choke
coil 26 for power supply are depicted in FIG. 7. A solid line 43
denotes impedance-frequency characteristics in the common mode. A
broken line 44 denotes impedance-frequency characteristics in the
differential mode. It is to be noted, for example, that the
impedance in both the common mode and the differential mode is
comparatively high in the neighborhood of 100 MHz. This suggests
that it is possible to suppress the high-frequency components (or
noise) in both of the modes.
[0047] Insertion loss-frequency characteristics of the capacitor 29
for noise removal are depicted in FIG. 8. This indicates that the
capacitor 29 having a capacitance of 1.5 .mu.F effectively
suppresses noise.
[0048] FIG. 9 depicts frequency characteristics for a loss factor
.mu.'' of the electromagnetic wave shielding layer 24b containing
ferrite and polymeric resin. Incidentally, the polymeric resin is
polypropylene and the electromagnetic wave shielding layer 24b
contains ferrite in an amount of 80 wt %. It is noted from FIG. 9
that the loss factor .mu.'' is as low as approximately 4 in the
low-frequency range.
2. Method for Producing USB Cable
[0049] The following is a description of a method for producing the
USB cable constructed as mentioned above.
[0050] The USB connector 21 is produced in the following manner.
The printed circuit board 22 is provided thereon with the
common-mode choke coils 26 and 27 as chip parts (noise filter) for
anti-noise measure. The power cable 13a and the GND cable 13b are
connected to the terminals 25a and 25d of the printed circuit board
22 respectively by soldering. Also, the signal cables 12a and 12b
are connected to the terminals 25b and 25c of the printed circuit
board 22 respectively by soldering. Then, the insulating resin
layer 24a as the inner molded part is formed by molding so that it
fills the space around the printed circuit board 22. Similarly, the
insulating resin layer 24a is subsequently surrounded with the
magnetic wave shielding layer 24b as the outer molded part which is
formed by molding. In this way, there is obtained the USB connector
21.
[0051] The .mu.USB connector 31 is also produced by molding in the
similar way to the USB connector 21 mentioned above.
[0052] The above-mentioned method for producing the USB cable saves
time for production of the USB cable because the USB connector 21
is prepared simply by covering the printed circuit board 22 with
resin by molding. Also, covering the printed circuit board 22 with
resin without any gap results in an improved shielding
performance.
3. Modified Embodiment
[0053] The foregoing is a detailed description of the embodiment of
the present disclosure. The present embodiment mentioned above is
not intended to restrict the scope of the present disclosure.
Various changes can be made without departing from the scope of the
present disclosure. The constitution, method, process, shape,
materials, and numerical values cited in the present embodiment
mentioned above are mere examples and variously modified as
needed.
[0054] What is disclosed herein is applicable to the cable or
connector conforming to the standard for USB Type-C. It is
applicable not only to the USB cable but also to HDMI (registered
trademark) cable and IEEE (Institute of Electrical and Electronics
Engineers) 1394 cable. The cable part may be the ordinary USB
cable.
[0055] In addition, the molded part 24 further has the insulating
resin layer 24c surrounding the electromagnetic wave shielding
layer 24b as depicted in FIG. 10. The insulating resin layer 24c
includes an insulating polymeric resin such as polypropylene. The
insulating resin layer 24c added to the molded part 24 realizes the
improved shielding performance.
[0056] Further, the molded part has the insulating resin layer
only. In this case, the insulating resin layer may have a
configuration to fill the space surrounding the printed circuit
board or the insulating resin layer may have a cavity around the
printed circuit board.
[0057] Further, both the common-mode choke coil for power supply
and the common-mode choke coil for signals are mounted on the same
plane of the printed circuit board.
[0058] Note that the present disclosure may be configured as
follows.
(1)
[0059] A cable including:
[0060] a cable part including at least one set of signal cables for
differential transmission, a ground cable, and a power cable;
and
[0061] a first connector and a second connector arranged at both
ends of the cable part,
[0062] in which at least one of the first connector and the second
connector has a common-mode choke coil connected to the ground
cable and the power cable.
(2)
[0063] The cable according to Paragraph (1) above, in which the
common-mode choke coil is effective in noise removal not only in a
common mode but also in a differential mode.
(3)
[0064] The cable according to Paragraph (1) or (2) above, in which
a connector having the common-mode choke coil further has a
condenser for noise removal which is placed between the ground
cable and the power cable.
(4)
[0065] The cable according to any one of Paragraphs (1) to (3)
above, in which a connector having the common-mode choke coil
further has a substrate having the common-mode choke coil mounted
thereon and an insulating resin layer covering the substrate.
(5)
[0066] The cable according to Paragraph (4) above, in which the
connector having the common-mode choke coil further has an
electromagnetic wave shielding layer covering the insulating resin
layer.
(6)
[0067] The cable according to Paragraph (5) above, in which the
electromagnetic wave shielding layer contains carbon or
ferrite.
(7)
[0068] The cable according to Paragraph (5) or (6) above, in which
the one set of signal cables is installed such that the one set of
signal cables does not come into contact with the electromagnetic
wave shielding layer.
(8)
[0069] The cable according to any one of Paragraphs (5) to (7)
above, in which, on a side of the connector having the
electromagnetic wave shielding layer, one end of the one set of
signal cables is shorter than one end of the ground cable and the
power cable.
(9)
[0070] The cable according to any one of Paragraphs (5) to (8)
above, in which, on a side of the connector having the
electromagnetic wave shielding layer, one end of the one set of
signal cables is covered with an insulating covering material.
(10)
[0071] The cable according to any one of Paragraphs (1) to (9)
above, in which one of the first connector and the second connector
has the common-mode choke coil connected to the ground cable and
the power cable, and the other of them has a ferrite bead arranged
in the ground cable and the power cable.
(11)
[0072] The cable according to any one of Paragraphs (1) to (10)
above, in which at least one of the first connector and the second
connector further has a common-mode choke coil connected to the one
set of signal cables.
REFERENCE SIGNS LIST
[0073] 11 Cable part [0074] 12a, 12b Signal cable [0075] 13a Power
cable [0076] 13b GND cable [0077] 21 USB connector (first
connector) [0078] 31 .mu.USB connector (second connector) [0079] 22
Printed circuit board [0080] 23 Plug [0081] 24 Molded part [0082]
24a Insulating resin layer [0083] 24b Electromagnetic wave
shielding layer [0084] 26, 27 Common-mode choke coil [0085] 29
Capacitor
* * * * *