Timing oscillators and related methods

• US 8,044,736 B2
• Filed: 04/29/2008
• Issued: 10/25/2011
• Est. Priority Date: 04/29/2008
• Status: Active Grant

• Current Assignee: Analog Devices, Inc.
• Original Assignee: Sand9, Inc.
• Inventors: Mohanty, Pritiraj, Zolfagharkhani, Guiti, Schoepf, Klaus Juergen, Gaidarzhy, Alexei, Crowley, Matthew J., Chen, David M.
• Primary Examiner(s): Johnson; Ryan
• Application Number:
  US12/111,535
• Publication Number:
  US 20090267700A1
• Time in Patent Office: 1,274 Days
• Field of Search: 331/116.R, 331/116.M, 331/154, 331/156, 331/158, 331/74, 331/77
• US Class Current: 331/156
• CPC Class Codes: H03B 5/30 with frequency-determining element being electromechanical resonator
• CPC Class Codes: H03L 1/00 Stabilisation of generator output against variations of physical values, e.g. power supply
• CPC Class Codes: H03L 1/04 Constructional details for maintaining temperature constant
• CPC Class Codes: H03L 7/16 Indirect frequency synthesis, i.e. generating a desired one of a number of predetermined frequencies using a frequency- or phase-locked loop

Abstract

Timing oscillators as well as related methods and devices are described. A timing oscillator may include a mechanical resonating structure with major elements and minor elements coupled to the major element. The timing oscillator can generate stable signals with low phase noise at very high frequencies which allows a timing oscillator to be used effectively in a number of devices including computers and mobile phones for time and data synchronization purposes. The signal generated by the timing oscillator can be tuned using a driver circuit and a compensation circuit.

Claims

1. A device comprising:

a timing oscillator formed on a first substrate, the timing oscillator comprising;

a micromechanical resonating structure configured to generate a first signal having a first frequency; and

a drive circuit coupled to the micromechanical resonating structure and configured to provide a drive signal to the micromechanical resonating structure to cause the micromechanical resonating structure to generate the first signal, wherein the drive circuit has a feedback loop including a tunable resistive component and a tunable capacitive component,

wherein the timing oscillator is configured to produce an output signal based at least partially on the first signal;

a dividing circuit formed on a second substrate and configured to receive the output signal of the timing oscillator and divide the output signal to produce a divided signal having a second frequency less than the first frequency; and

a package surrounding the first substrate and the second substrate.

2. The device of claim 1, wherein the timing oscillator comprises a bank of micromechanical resonating structures, each of the micromechanical resonating structures of the bank designed to provide a respective output signal, the bank of micromechanical resonating structures comprising the micromechanical resonating structure, and

wherein the timing oscillator further comprises at least one switch coupled to the bank of micromechanical resonating structures and configured to select a respective output signal from one of the micromechanical resonating structures.

3. The device of claim 2, wherein at least one micromechanical resonating structure of the bank of micromechanical resonating structures has a large dimension of less than 100 microns.

4. The device of claim 2, further comprising a filter configured to filter the first signal.

5. The device of claim 2, wherein at least one micromechanical resonating structure of the bank of micromechanical resonating structures includes a major element and a minor element coupled to the major element.

6. The device of claim 5, wherein the minor element has a large dimension of between 0.001 micron and 1 micron.

7. The device of claim 5, wherein the major element has a large dimension of between 0.01 micron and 100 micron.

8. The device of claim 2, wherein the respective output signals have different frequencies from each other.

9. The device of claim 2, further comprising a first compensation circuit configured to receive the respective output signals from the bank of micromechanical resonating structures.

10. The device of claim 9, wherein the first compensation circuit is configured to stabilize the respective output signals of the micromechanical resonating structures of the bank of micromechanical resonating structures.

11. The device of claim 10, further comprising a second compensation circuit coupled to the first compensation circuit.

12. The device of claim 1, wherein the feedback loop includes an operational amplifier coupled to the tunable resistive component and/or the tunable capacitive component.