Multi-phase Closed Loop LC Tank Circuits

• US 20080074202A1
• Filed: 06/18/2007
• Published: 03/27/2008
• Est. Priority Date: 07/19/2005
• Status: Abandoned Application

• Current Assignee: Intellectual Ventures Fund 70 LLC (Intellectual Ventures LLC)
• Original Assignee: LC Tank LLC
• Inventors: Gabara, Thaddeus
• Application Number:
  US11/764,797
• Publication Number:
  US 20080074202A1
• Time in Patent Office: Days
• US Class Current: 331/50
• CPC Class Codes: G06F 1/10 Distribution of clock signals , e.g. skew
• CPC Class Codes: H01L 2224/16145 the bodies being stacked
• CPC Class Codes: H03B 2200/0076 Power combination of several oscillators oscillating at the same frequency
• 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 5/1243 the means comprising voltage variable capacitance diodes

Abstract

LC tank circuits can be coupled together to form closed loop oscillators. The interconnectivity of these LC tank circuits were performed by a physical connection such as a metal interconnect. The LC tank circuits may also comprise a plurality of inductors that are coupled together in parallel. These closed loop oscillators generate oscillations which have multi-phase components. Such circuits are useful for RF designs, clock generation for VLSI chips, adiabatic circuitry, analog circuitry, and high-speed digital circuitry.

Claims

1. A closed loop oscillator, comprising:

a first terminal and a second terminal;

a plurality of oscillators;

wherein,

each oscillator comprises;

a first input node and a second input node;

a first output node and a second output node; and

,

and LC tank circuit coupled to the first and second output nodes;

wherein

the LC tank circuit is comprised of a plurality of inductors connected in parallel;

the first terminal is coupled to the first input node of a first oscillator;

the second terminal is coupled to the second input node of the first oscillator; and

,

the plurality of oscillators are coupled in series;

wherein

the first output node of a previous oscillator is coupled to one of the input nodes of a next oscillator;

the second output node of the previous oscillator is coupled to the remaining input node of the next oscillator;

the first output node of a last oscillator is coupled to either of the first or second terminals; and

,

the second output node of the last oscillator is coupled to the remaining terminal.

2. The oscillator of claim 1, wherein:

the LC tank circuit further comprises at least one capacitor.

3. The oscillator of claim 1, wherein:

each oscillator further comprises;

a regenerative circuit coupled to the first and second output nodes.

4. The oscillator of claim 1, wherein:

each oscillator further comprises;

a first component coupling the first output node to a power supply node controlled by the first input node; and

,

a second component coupling the second output node to the power supply node controlled by the second input node.

5. The oscillator of claim 4, wherein:

the first and second components are MOS transistors.

6. The oscillator of claim 1, further comprising:

at least one balanced pair of output signals.

7. The oscillator of claim 6, wherein:

the balanced pair of output signals each drive a capacitor load.

8. The oscillator of claim 1, wherein:

the first and second outputs of each oscillator provides the balanced pair of output signals.

9. The oscillator of claim 8, wherein:

the collection of the balanced pair of output signals generates a multi-phase clock signal.

10. The oscillator of claim 1, wherein:

the plurality of oscillators consist of an odd number of oscillators.

11. The oscillator of claim 10, wherein:

the first and second output nodes of each oscillator cross each other an even number of times while forming the closed loop of the oscillator.

12. The oscillator of claim 1, wherein:

the plurality of oscillators consist of an even number of oscillators.

13. The oscillator of claim 12, wherein:

the first and second output nodes of each oscillator cross each other an odd number of times while forming the closed loop of the oscillator.

15. The method of claim 13, wherein:

each oscillator further comprises;

a cross-coupled regenerative circuit coupled to the first and second output nodes.

16. The method of claim 13, wherein:

each oscillator further comprises;

a first component controlled by the first input node that couples a power supply node to the first output node; and

,

a second component controlled by the second input node that couples the power supply mode to the second output node.

17. The method of claim 13, wherein:

the first and second output nodes of each oscillator can drive a capacitor load.

18. The method of claim 13, wherein:

the first and second output nodes of each oscillator provides a balanced clock signal.

19. The method of claim 18, wherein:

the collection of the balanced signals generates a multi-phase clock signal.

14. A method of forming a closed loop oscillator, comprising the steps of:

selecting a plurality of oscillators where each oscillator comprises;

a first input node and a second input node;

a first output node and second output node; and

an LC tank circuit coupled to the first and second output nodes;

wherein,

the LC tank circuit is comprised of a plurality of inductors connected in parallel;

connecting the plurality of oscillators in series to form the closed loop;

wherein,

the first output node of a previous oscillator is coupled to one of the input nodes of a next oscillator; and

,

the second output node of the previous oscillator is coupled to the remaining input node of the next oscillator;

coupling the first output node of a last oscillator to either of the first or second input nodes of a first oscillator; and

,

coupling the second output node of the last oscillator to the remaining input node of the first oscillator;

thereby,

forming the closed loop oscillator.

20. A closed loop oscillator, comprising:

a plurality of oscillators;

wherein,

each oscillator comprises;

a first input node and a second input node;

a first output node and a second output node;

a first component coupled between a power supply node and the first output node;

wherein

the first component is controlled by the first input node;

a second component coupled between the power supply node and the second output node;

wherein,

the second component is controlled by the second input node;

an LC tank circuit coupled to the first and second output nodes; and

,

a regenerative circuit coupled to the first and second output nodes; and

,

the plurality of oscillators coupled in series to form a closed loop;

wherein,

the first output node of a previous oscillator is coupled to one of the input nodes of a next oscillator;

the second output node of the previous oscillator is coupled to the remaining input node of the next oscillator;

the first output node of a last oscillator is coupled to one of the input nodes of a first oscillator; and

,

the second output node of the last oscillator is coupled to the remaining input node of the first oscillator.

21. The oscillator of claim 20, wherein:

the LC tank circuit further comprises at least one capacitor.

22. The oscillator of claim 20, wherein:

an inductance of the LC tank circuit is comprised of a plurality of inductors connected in parallel.

23. The oscillator of claim 20, wherein:

each oscillator further comprises;

a regenerative circuit coupled to the first and second output nodes.

24. The oscillator of claim 20, wherein:

the first and second components are MOS transistors.

25. The oscillator of claim 20, further comprising:

at least one balanced pair of output signals.

26. The oscillator of claim 25, wherein:

the balanced pair of output signals each drive a capacitor load.

27. The oscillator of claim 20, wherein:

the first and second outputs of each oscillator provides the balanced pair of output signals.

28. The oscillator of claim 27, wherein:

the collection of the balanced pair of output signals generates a multi-phase clock signal.

29. The oscillator of claim 20, wherein:

the plurality of oscillators consist of an odd number of oscillators.

30. The oscillator of claim 29, wherein:

the first and second output nodes of each oscillator cross each other an even number of times while forming the closed loop of the oscillator.

31. The oscillator of claim 20, wherein:

the plurality of oscillators consist of an even number of oscillators.

32. The oscillator of claim 31, wherein:

the first and second output nodes of each oscillator cross each other an odd number of times while forming the closed loop of the oscillator.