US 7,116,203 B2 · Circuit using choke coil and choke coil

Abstract

A first winding of a choke coil is closely wound in a single layer on the outer periphery of a substantially cylindrical body portion of a first bobbin. A second winding is closely wound in a single layer over the first winding. A third winding is closely wound in a single layer on the outer periphery of a substantially cylindrical body portion of a second bobbin. A fourth winding is closely wound in a single layer over the third winding. The first, second, third and fourth windings are wound so as to mutually strengthen magnetic fluxes when an in-phase noise current flows. The first and second windings are connected to a pair of signal lines via which differential transmission communication is performed and on which a power supply current is sent out. The third and fourth windings are connected to a pair of signal lines via which differential transmission communication is performed and on which the power supply current returns. Thus, a circuit including a compact choke coil having large inductance and better high-frequency characteristics, and the choke coil is provided.

Claims24

Dependent claims

A circuit including a choke coil, comprising:

first and second signal lines via which differential transmission communication is performed and on which a power supply current is sent out;
third and fourth signal lines via which differential transmission communication is performed and on which the power supply current returns;
and
a choke coil having first, second, third, and fourth windings, and a magnetic core constituting a closed magnetic path in which the first, second, third, and fourth windings are wound;
wherein
the first, second, third, and fourth windings are electrically connected to the first, second, third, and fourth signal lines, respectively;
the first winding and the second winding are wound in the same direction so that magnetic fluxes generated in the magnetic core are mutually strengthened when an in-phase noise current flows, and the third winding and the fourth winding are wound in the same direction so that magnetic fluxes generated in the magnetic core are mutually strengthened when an in-phase noise current flows;
and
the first and second windings and the third and fourth windings are wound so that magnetic fluxes generated in the magnetic core are mutually strengthened when an in-phase noise current flows.

6 more elements

A choke coil that is inserted in a signal line having communication and power-provision functions, comprising:

first and second bobbins each having a substantially cylindrical body portion;
a first winding that is closely wound in a single layer on the substantially cylindrical body portion of the first bobbin and a second winding that is closely wound in
a single layer over the first winding;
a third winding that is closely wound in a single layer on the substantially cylindrical body portion of the second bobbin and a fourth winding that is closely wound in a single layer over the third winding;
and
a magnetic core having leg portions that are inserted through holes in the substantially cylindrical body portions of the first and second bobbins to define a closed magnetic path;
wherein
the first winding and the second winding are wound in the same direction so that magnetic fluxes generated in the magnetic core are mutually strengthened when an in-phase noise current flows;
the third winding and the fourth winding are wound in the same direction so that magnetic fluxes generated in the magnetic core are mutually strengthened when an in-phase noise current flows;
and
the first and second windings and the third and fourth windings are wound so that magnetic fluxes generated in the magnetic core are mutually strengthened when an in-phase noise current flows.

8 more elements

Dependencies are inferred from the claim text.

Circuit using choke coil and choke coil

Life of this patent

Circuit using choke coil and choke coil

Life of this patent

Abstract

Claims24