Cross-coupled Inductor Pair Formed in an Integrated Circuit

• US 20090108978A1
• Filed: 12/31/2008
• Published: 04/30/2009
• Est. Priority Date: 08/24/2005
• Status: Active Grant

• Current Assignee: Broadcom International Pte Ltd. (Broadcom, Inc.)
• Original Assignee: Avago Technologies PTE (Broadcom, Inc.)
• Inventors: Loke, Alvin Leng Sun, Martin, Robert James, Fisher, Philip Wilfred
• Granted Patent: US 7,782,166 B2
• Time in Patent Office: Days
• US Class Current: 336/200
• CPC Class Codes: H01F 2017/0026 Multilayer LC-filter
• CPC Class Codes: H01F 27/40 Structural association with built-in electric component, e.g. fuse
• CPC Class Codes: H01L 23/5227 Inductive arrangements or effects of, or between, wiring layers other inductive arrangements H01L23/645
• CPC Class Codes: H01L 2924/00 Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
• CPC Class Codes: H01L 2924/0002 Not covered by any one of groups H01L24/00, H01L24/00 and H01L2224/00
• CPC Class Codes: H01L 2924/3011 Impedance
• CPC Class Codes: H03B 5/1212 the amplifier comprising a pair of transistors, wherein an output terminal of each being connected to an input terminal of the other, e.g. a cross coupled pair
• CPC Class Codes: H03B 5/1228 the amplifier comprising one or more field effect transistors
• CPC Class Codes: H03B 5/124 the means comprising a voltage dependent capacitance
• CPC Class Codes: H03B 5/1841 the frequency-determining element being a strip line resonator H03B5/1805, H03B5/1817, H03B5/1864 and H03B5/1882 take precedence
• CPC Class Codes: H03H 5/12 with at least one voltage- or current-dependent element

Abstract

Cross-coupled first and second helical inductors formed in an IC. The cross-coupled first and second helical inductors comprise a first helical conductor having a first portion and a second portion, and a second helical conductor having a first portion and a second portion. The second helical conductor is in close proximity to the first helical conductor. The first helical inductor is formed by the first portion of the first helical conductor and the second portion of the second helical conductor. The second helical inductor is formed by the second portion of the first helical conductor and the first portion of the second helical conductor.

Claims

1. A cross-coupled helical inductor configuration formed in an integrated circuit (IC), the cross-coupled helical inductor configuration comprising:

a first helical inductor comprising a first plurality of conductors, wherein the conductors of said first plurality of conductors are disposed in respective layers of the IC and are conductively connected to form a first helical pattern of conductors;

a second helical inductor comprising a second plurality of conductors, wherein the conductors of said second plurality of conductors are disposed in respective layers of the IC and are conductively connected to form a second helical pattern of conductors, the first and second helical inductors being positioned in close proximity to one another in the IC;

a first coupling conductor that connects at least a first one of said first plurality of conductors to at least a first one of said second plurality of conductors; and

a second coupling conductor that connects at least a second one of said second plurality of conductors to at least a second one of said first plurality of conductors, wherein if a first electrical current is introduced into said first helical inductor, the connection between said at least a first one of said first plurality of conductors and said at least a first one of said second plurality of conductors causes a first electromagnetic field to exist in a first portion of said first helical inductor and a second electromagnetic field to exist in a second portion of said second helical inductor, the first and second electromagnetic fields being oppositely directed, and wherein the oppositely directed electromagnetic fields result in reduced noise levels in a substrate of the IC.

2. The cross-coupled helical inductor configuration of claim 1, wherein if a second electrical current is introduced into said second helical inductor, the connection between said at least a second one of said first plurality of conductors and said at least a second one of said second plurality of conductors causes a third electromagnetic field to exist in a first portion of said second helical inductor and a fourth electromagnetic to exist in a second portion of said first helical inductor, the third and fourth electromagnetic fields being oppositely directed, the first and third electromagnetic fields being in a same direction and the second and fourth electromagnetic fields being in a same direction, and wherein the oppositely directed third and fourth electromagnetic fields result in reduced noise levels in the substrate of the IC.

3. A method for generating magnetic coupling in an integrated circuit (IC), the method comprising:

providing an IC having first and second helical inductors formed therein in close proximity to one another, the first helical inductor comprising a first plurality of conductors disposed in respective layers of the IC and conductively connected to form a first helical pattern of conductors, the second helical inductor comprising a second plurality of conductors disposed in respective layers of the IC and conductively connected to form a second helical pattern of conductors, at least a first one of said first plurality of conductors being connected by a first coupling conductor to at least a first one of said second plurality of conductors, at least a second one of said first plurality of conductors being connected by a second coupling conductor to at least a second one of said second plurality of conductors; and

causing at least a first electrical current to travel in the first and second helical inductors, wherein the first electrical current is electromagnetically coupled by the first coupling conductor from said first one of said first plurality of conductors into said first one of said second plurality of conductors, and wherein the first electrical current causes a first electromagnetic field to exist in a first portion of said first helical inductor and a second electromagnetic filed to exist in a second portion of said second helical inductor, wherein the first and second electromagnetic fields are oppositely directed, and wherein the oppositely directed electromagnetic fields result in reduced noise levels in a substrate of the IC.

4. The method of claim 3, further comprising:

causing at least a second electrical current to travel in the first and second helical inductors, wherein the second electrical current that travels in the second helical inductor is electromagnetically coupled by the second coupling conductor from said second one of said second plurality of conductors into said second one of said first plurality of conductors, and wherein the second electrical current causes a third electromagnetic field to exist in a first portion of said second helical inductor and a fourth electromagnetic to exist in a second portion of said first helical inductor, wherein the third and fourth electromagnetic fields are oppositely directed.

5. The method of claim 4, wherein the first and third electromagnetic fields are in a same direction and the second and fourth electromagnetic fields are in a same direction, and wherein the oppositely directed third and fourth electromagnetic fields result in reduced noise levels in the substrate of the IC.