Timing oscillators and related methods

• US 8,044,737 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: Crowley, Matthew J., Mohanty, Pritiraj, Zolfagharkhani, Guiti, Schoepf, Klaus Juergen, Gaidarzhy, Alexei, Chen, David M.
• Primary Examiner(s): Johnson; Ryan
• Application Number:
  US12/111,544
• Publication Number:
  US 20090267699A1
• Time in Patent Office: 1,274 Days
• Field of Search: 331/68, 331/116.R, 331/116.M, 331/154, 331/156, 331/158
• US Class Current: 331/156
• CPC Class Codes: H03B 5/30 with frequency-determining element being electromechanical resonator
• CPC Class Codes: H03H 2009/02299 Comb-like, i.e. the beam comprising a plurality of fingers or protrusions along its length
• CPC Class Codes: H03H 3/0077 by tuning of resonance frequency
• CPC Class Codes: H03H 9/2463 Clamped-clamped beam resonators
• CPC Class Codes: H03L 1/02 against variations of temperature only
• CPC Class Codes: H03L 7/18 using a frequency divider or counter in the loop H03L7/20, H03L7/22 take precedence

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 timing oscillator designed to produce an output signal, the timing oscillator comprising:

at least one mechanical resonating structure, the at least one mechanical resonating structure configured to produce a resonator signal;

at least one drive circuit coupled to the at least one mechanical resonating structure and configured to drive the at least one mechanical resonating structure to produce the resonator signal, wherein the at least one drive circuit has a feedback loop including a tunable resistive component and a tunable capacitive component; and

a compensation circuit configured to compensate an operating frequency of the timing oscillator,

wherein a total height of the timing oscillator is less than 0.5 mm.

2. The timing oscillator of claim 1, further comprising a filter configured to filter the resonator signal.

3. The timing oscillator of claim 1, wherein the at least one mechanical resonating structure is formed on a first substrate and wherein the at least one drive circuit is formed on a second substrate.

4. The timing oscillator of claim 3, wherein the second substrate is coupled to the first substrate at a bonding site in a flipped orientation.

5. The timing oscillator of claim 3, wherein the second substrate is coupled to the first substrate using interconnects.

6. The timing oscillator of claim 3, wherein the first substrate is silicon and the second substrate is silicon.

7. The timing oscillator of claim 3, wherein the first substrate is a device wafer and the second substrate is a cap wafer.

8. The timing oscillator of claim 3, wherein the first substrate and the second substrate are arranged in parallel relation to each other.

9. The timing oscillator of claim 1, wherein the compensation circuit contains a calibration table storing information relating to the operational frequency of the at least one mechanical resonating structure as a function of temperature.

10. The timing oscillator of claim 1, wherein the feedback loop of the at least one drive circuit comprises an operational amplifier.

11. The timing oscillator of claim 2, wherein the feedback loop of the at least one drive circuit comprises an operational amplifier.

12. The timing oscillator of claim 4, wherein the feedback loop of the at least one drive circuit comprises an operational amplifier.

13. The timing oscillator of claim 5, wherein the feedback loop of the at least one drive circuit comprises an operational amplifier.

14. The timing oscillator of claim 6, wherein the feedback loop of the at least one drive circuit comprises an operational amplifier.

15. The timing oscillator of claim 7, wherein the feedback loop of the at least one drive circuit comprises an operational amplifier.

16. The timing oscillator of claim 8, wherein the feedback loop of the at least one drive circuit comprises an operational amplifier.

17. The timing oscillator of claim 3, wherein the feedback loop of the at least one drive circuit comprises an operational amplifier.

18. The timing oscillator of claim 9, wherein the feedback loop of the at least one drive circuit comprises an operational amplifier.