Common-mode choke coil

1. A common-mode choke coil comprising:

a core configured to extend in a predetermined direction;

first and second wires intertwined and wound together around the core, wherein the first wire is only one wire and the second wire is only one wire;

first and second external electrodes provided at both ends of the core so as to be arranged in the predetermined direction; and

third and fourth external electrodes provided at the both ends of the core so as to be separated from the first and second external electrodes, respectively, in a first direction perpendicular to the predetermined direction, wherein:

in a plan view from a second direction perpendicular to both the predetermined direction and the first direction, a first end portion of the first wire is untwisted from a first end portion of the second wire at a first corner of the core;

the first end portion of the first wire and the first end portion of the second wire are connected to the first external electrode and the third external electrode, respectively;

in the plan view from the second direction, a second end portion of the first wire is untwisted from a second portion of the second wire at a second corner of the core diagonal to the first corner;

the second end portion of the first wire and the second end portion of the second wire are connected to the second external electrode and the fourth external electrode, respectively; and

at least a part of the first wire of the intertwined and wound first and second wires makes contact with at least a part of the second wire of an adjacent segment of the intertwined and wound first and second wires.

2. The common-mode choke coil according to claim 1 , wherein the first and second wires are intertwined and wound together around the core with a gap between at least a part of each of the intertwined and wound first and second wires.

3. The common-mode choke coil according to claim 1 , wherein the first wire and the second wire are intertwined and wound together around the core along an entire length of the core between the first corner and the second corner.

4. The common-mode choke coil according to claim 1 , wherein differential-mode signals are inputted to the first and third external electrodes and outputted from the second and fourth external electrodes, wherein, when the differential-mode signals contain common-mode noise, the common-mode noise causes the first and second wires to produce magnetic flux in a same direction, and wherein the magnetic flux is intensified resulting in impedance against common-mode components, so that common-mode noise is prevented from passing through the first and second wires.

5. The common-mode choke coil according to claim 1 , wherein the contact with the adjacent segment repeats in regular intervals along a length of the intertwined and wound first and second wires.

6. A common-mode choke coil comprising:

a core configured to extend in a predetermined direction;

first and second wires intertwined and wound together around the core, wherein at least a part of the intertwined and wound first and second wires makes contact with an adjacent segment of the intertwined and wound first and second wires with a gap between the intertwined and wound first and second wires and the adjacent segment of the intertwined and wound first and second wires, and wherein the first wire is only one wire and the second wire is only one wire;

first and second external electrodes provided at both ends of the core so as to be arranged in the predetermined direction; and

third and fourth external electrodes provided at the both ends of the core so as to be separated from the first and second external electrodes, respectively, in a first direction perpendicular to the predetermined direction, wherein:

in a plan view from a second direction perpendicular to both the predetermined direction and the first direction, a first end portion of the first wire is untwisted from a first end portion of the second wire at a first corner of the core;

the first end portion of the first wire and the first end portion of the second wire are connected to the first external electrode and the third external electrode, respectively;

in the plan view from the second direction, a second end portion of the first wire is untwisted from a second portion of the second wire at a second corner of the core diagonal to the first corner;

the second end portion of the first wire and the second end portion of the second wire are connected to the second external electrode and the fourth external electrode, respectively; and

at least a part of the first wire of the intertwined and wound first and second wires makes contact with at least a part of the second wire of an adjacent segment of the intertwined and wound first and second wires.

7. The common-mode choke coil according to claim 6 , wherein the first wire and the second wire are intertwined and wound together around the core along an entire length of the core between the first corner and the second corner.

8. The common-mode choke coil according to claim 6 , wherein differential-mode signals are inputted to the first and third external electrodes and outputted from the second and fourth external electrodes, wherein, when the differential-mode signals contain common-mode noise, the common-mode noise causes the first and second wires to produce magnetic flux in a same direction, and wherein the magnetic flux is intensified resulting in impedance against common-mode components, so that common-mode noise is prevented from passing through the first and second wires.

9. The common-mode choke coil according to claim 6 , wherein the gap and the contact with the adjacent segment repeat in regular intervals along a length of the intertwined and wound first and second wires.