Varainductor and operation method thereof based on mutual capacitance

• US 9,812,251 B2
• Filed: 10/12/2016
• Issued: 11/07/2017
• Est. Priority Date: 12/18/2013
• Status: Active Grant

• Current Assignee: Taiwan Semiconductor Manufacturing Company Limited
• Original Assignee: Taiwan Semiconductor Manufacturing Company Limited
• Inventors: Liu, Yi-Hsuan, Hsieh, Hsieh-Hung, Jou, Chewn-Pu, Hsueh, Fu-Lung
• Primary Examiner(s): JAGER, RYAN C
• Application Number:
  US15/291,520
• Publication Number:
  US 20170032891A1
• Time in Patent Office: 391 Days
• Field of Search: 336150, 327157
• CPC Class Codes: H01F 2021/125 Printed variable inductor with taps, e.g. for VCO
• CPC Class Codes: H01F 21/12 discontinuously variable, e.g. tapped
• CPC Class Codes: H01F 27/2804 Printed windings
• CPC Class Codes: H01F 27/40 Structural association with built-in electric component, e.g. fuse
• CPC Class Codes: H01F 27/42 Circuits specially adapted for the purpose of modifying, or compensating for, electric characteristics of transformers, reactors, or choke coils circuits for controlling transformers, reactors or choke coils, for the purpose of obtaining a desired output H02P13/00; impedance networks H03H
• CPC Class Codes: H01F 29/02 with tappings on coil or winding; with provision for rearrangement or interconnection of windings
• CPC Class Codes: H01L 23/5226 Via connections in a multilevel interconnection structure
• CPC Class Codes: H01L 23/5227 Inductive arrangements or effects of, or between, wiring layers other inductive arrangements H01L23/645
• CPC Class Codes: H01L 23/528 Geometry or layout of the interconnection structure H01L27/0207 takes precedence; algorithms G06F30/00
• CPC Class Codes: H01L 23/585 comprising conductive layers or plates or strips or rods or rings H01L23/60, H01L23/62, H01L23/64, H01L23/66 take precedence
• CPC Class Codes: H01L 27/0688 Integrated circuits having a three-dimensional layout
• CPC Class Codes: H03B 2201/0216 the means being an element with a variable inductance
• 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 5/1256 the means comprising a variable inductance
• CPC Class Codes: H03L 7/099 concerning mainly the controlled oscillator of the loop

Abstract

A varainductor includes a spiral inductor, a ground ring, and a floating ring. The floating ring is disposed between the ground ring and the spiral inductor and surrounds a ring portion of the spiral inductor. A switching element, controlled by a switch control signal, selectively electrically connects the ground ring to the floating ring. The switching element includes one or more switches. The one or more switches are controlled by one or more signals of the switch control signal to adjust the inductance level of the varainductor.

Claims

1. A varainductor comprising:

a spiral inductor comprising a ring portion;

a ground ring surrounding at least the ring portion of the spiral inductor;

a floating ring disposed between the ground ring and the spiral inductor, wherein an inductance level of the varainductor is based on a mutual capacitance between the spiral inductor and the floating ring and a mutual capacitance between the floating ring and the ground ring; and

an array of switches, the array of switches configured to selectively electrically connect the ground ring to the floating ring.

2. The varainductor of claim 1, wherein each switch of the array of switches is configured to receive a same switch control signal.

3. The varainductor of claim 1, wherein at least one switch of the array of switches is configured to receive a first switch control signal and at least another switch of the array of switches is configured to receive a second switch control signal, wherein the second switch control signal is different from the first control signal.

4. The varainductor of claim 1, wherein the floating ring is located in a first tier of a monolithic three-dimensional integrated circuit (3DIC), the ground ring is located in a second tier of the monolithic 3DIC different from the first tier, and the floating ring is configured to be selectively electrically connected to the ground ring through at least one inter-tier via.

5. The varainductor of claim 1, wherein the spiral inductor includes a first portion located a first distance from a top surface of a substrate, and a second portion located a second distance from the top surface of the substrate, and the first distance is different from the second distance.

6. The varainductor of claim 1, wherein at least one portion of the spiral inductor is located in a first tier of a monolithic three-dimensional integrated circuit (3DIC), and at least one of the floating ring or the ground ring is located in a second tier of the monolithic 3DIC different from the first tier.

7. The varainductor of claim 1, wherein the array of switches includes at least one transistor, the at least one transistor configured to selectively electrically connect the floating ring located in a first tier of a monolithic three-dimensional integrated circuit (3DIC) to the ground ring located in a second tier of the monolithic 3DIC different from the first tier, and the at least one transistor is configured to selectively electrically connect the floating ring to the ground ring through an inter-tier via.

8. The varainductor of claim 1, wherein the floating ring is spaced from the ground ring by a distance ranging from about 2 μ

m to about 50 μ

m.

9. The varainductor of claim 1, wherein the spiral inductor further comprises at least one input port and at least one output port.

10. The varainductor of claim 9, wherein the at least one output port extends from the ring portion to a location outside the ground ring.

11. The varainductor of claim 1, wherein the array of switches comprises:

a first switch disposed on a first side of the spiral inductor; and

a second switch disposed on a second side of the spiral inductor opposite the first side.

12. The varainductor of claim 1, wherein the floating ring is located in a same tier of a complementary metal oxide semiconductor (CMOS) circuit as the ground ring.

13. A circuit comprising:

a spiral inductor;

a ground ring;

a floating ring disposed between the ground ring and the spiral inductor; and

a switch configured to selectively electrically connect the ground ring to the floating ring, wherein an inductance level of the circuit is based on a mutual capacitance between the spiral inductor and the floating ring and a mutual capacitance between the floating ring and the ground ring.

14. The circuit of claim 13 wherein the spiral inductor comprises a ring portion, wherein the ground ring surrounds at least the ring portion of the spiral inductor.

15. The circuit of claim 13 further comprising an array of switches, wherein the array of switches is configured to selectively electrically connect the ground ring to the floating ring and at least one switch of the array of switches is configured to receive a different control signal from another control signal received at another switch of the array of switches.

16. The circuit of claim 15 wherein the array of switches includes at least one transistor, the at least one transistor configured to selectively electrically connect the floating ring located in a first tier of a monolithic three-dimensional integrated circuit (3DIC) to the ground ring located in a second tier of the monolithic 3DIC different from the first tier.

17. The circuit of claim 15 wherein the array of switches comprises:

a first switch disposed on a first side of the spiral inductor; and

a second switch disposed on a second side of the spiral inductor opposite the first side.

18. A method of operation of a varainductor, the method comprising:

receiving an operating voltage on a spiral inductor;

receiving at least one control signal at an array of switches, wherein the at least one control signal closes a switch electrically coupled to a floating ring and a ground ring surrounding the spiral inductor, wherein

an inductance level of the varainductor is based on a mutual capacitance between the spiral inductor and the floating ring and a mutual capacitance between the floating ring and the ground ring.

19. The method of claim 18 wherein each switch of the array of switches receives a same switch control signal.

20. The method of claim 18 wherein at least one switch of the array of switches receives a different switch control signal from another switch control signal received at another switch of the array of switches.