Integrated MEMS device and method of use

• US 8,567,246 B2
• Filed: 12/28/2010
• Issued: 10/29/2013
• Est. Priority Date: 10/12/2010
• Status: Active Grant

• Current Assignee: Invensense Incorporated (TDK Corporation)
• Original Assignee: Invensense Incorporated (TDK Corporation)
• Inventors: Shaeffer, Derek, Cagdaser, Baris, Lo, Chiung C., Seeger, Joseph
• Primary Examiner(s): KWOK, HELEN C
• Application Number:
  US12/979,960
• Publication Number:
  US 20120086446A1
• Time in Patent Office: 1,036 Days
• Field of Search: 735/040.4, 735/041.2, 735/041.4, 735/041.6, 735/143.2, 735/10, 735/11
• US Class Current: 73/504.12
• CPC Class Codes: G01R 33/0286 comprising microelectromechanical systems [MEMS] MEMS devices in general B81B
• CPC Class Codes: H03H 3/0073 Integration with other electronic structures
• CPC Class Codes: Y10T 29/4913 Assembling to base an electrical component, e.g., capacitor, etc.

Abstract

An integrated MEMS device is disclosed. The system comprises a MEMS resonator; and a MEMS device coupled to a MEMS resonator. The MEMS resonator and MEMS device are fabricated on a common substrate so that certain characteristics of the MEM resonator and MEMS device track each other as operating conditions vary.

Claims

1. An integrated MEMS system comprising:

a MEMS resonator; and

at least one MEMS device coupled to the MEMS resonator, wherein the MEMS resonator and the at least one MEMS device are fabricated on a common substrate, wherein a gain peak of the MEMS resonator tracks with an offset with respect to a gain peak of the at least one MEMS device to optimize the performance of the at least one MEMS device.

2. The system of claim 1, wherein the MEMS resonator is coupled to an electronic circuit.

3. The system of claim 1, which further includes at least one frequency translation circuit coupled between the MEMS resonator and the at least one MEMS device.

4. The system of claim 3, a gain peak of the MEMS resonator being translated by a frequency offset provided by the frequency translation circuit to achieve alignment with respect to a gain peak of the MEMS device to optimize the at least one MEMS device performance.

5. The system of claim 3, wherein the at least one frequency translation circuit comprises a plurality of frequency translation circuits and the at least one MEMS device comprises a plurality of MEMS devices.

6. A MEMS Lorentz-force magnetometer system comprising:

a MEMS resonator;

an oscillator coupled to the MEMS resonator; and

a MEMS device coupled to the oscillator, wherein the MEMS resonator and the MEMS device are fabricated on a common substrate, wherein a gain peak of the MEMS resonator tracks with an offset with respect to a gain peak of the at least one MEMS device to optimize the performance of the at least one MEMS device;

the MEMS device further comprising a flexible element, the oscillator operable to produce an oscillation substantially at a resonant frequency of the MEMS resonator, the oscillator operable to drive a current in the flexible element, the flexible element operable to deflect in response to a Lorentz force.

7. The system of claim 6 which further comprises a capacitance coupled to the flexible element, and a sense amplifier coupled to the capacitance;

the capacitance operable to change in response to the deflection of the flexible element, and the sense amplifier operable to amplify a capacitance change.

8. The system of claim 6, wherein the flexible element comprises a flexible beam.

9. The system of claim 6, wherein the MEMS resonator is further coupled to an electronic circuit other than the oscillator.

10. The system of claim 9, wherein the electronic circuit comprises a digital signal processor.

11. The system of claim 9, wherein the electronic circuit comprises:

an analog to digital converter (ADC) coupled to a sense amplifier;

a digital signal processor (DSP) coupled to the ADC; and

a phase locked loop (PLL) coupled to the ADC, the DSP and the oscillator.

12. The system of claim 6, which further includes at least one frequency translation circuit coupled between the oscillator and the MEMS resonator.

13. The system of claim 12, wherein the at least on frequency translation circuit comprises a phase locked loop (PLL).

14. The system of claim 6, wherein the MEMS resonator comprises a gyroscope.

15. A method comprising:

fabricating a MEMS resonator and at least one MEMS device on a common substrate at substantially the same time, wherein there is a correlation between at least one characteristic of the MEMs resonator and at least one characteristic of the MEMS device, wherein the step of fabricating is effective to substantially track with an offset a gain peak of the MEMS resonator with respect to a gain peak of the at least one MEMS device to optimize the performance of the at least one MEMS device.

16. The method of claim 15 further comprising translating at least one frequency corresponding to a gain peak of the MEMS resonator between the MEMS resonator and the at least one MEMS device.

17. The method of claim 16, wherein the step of translating the at least one frequency is effective to substantially align the at least one frequency with respect to a gain peak of the at least one MEMS device.

18. The method of claim 16, wherein the step of translating the at least one frequency comprises translating a plurality of frequencies and the at least one MEMS device comprises a plurality of MEMS devices, wherein the plurality of MEMS devices receives the plurality of frequency translations.