Method of reducing gyroscope oscillator start-up time and device therefor

• US 9,464,899 B2
• Filed: 09/25/2014
• Issued: 10/11/2016
• Est. Priority Date: 01/25/2013
• Status: Active Grant

• Current Assignee: Movella Incorporated (Movella Holdings, Inc.)
• Original Assignee: mCube, Inc.
• Inventors: Zhang, Wenhua
• Primary Examiner(s): OLAMIT, JUSTIN N
• Application Number:
  US14/497,317
• Publication Number:
  US 20150090034A1
• Time in Patent Office: 747 Days
• Field of Search: 735/041.2
• US Class Current: 1/1
• CPC Class Codes: B81B 2201/0242 Gyroscopes
• CPC Class Codes: G01C 19/5776 Signal processing not specific to any of the devices covered by groups G01C19/5607 - G01C19/5719
• CPC Class Codes: H03B 2200/0094 Measures to ensure starting of oscillations

Abstract

A gyroscope device and method of operation therefor. The gyroscope device can include a power input, a charge pump portion coupled to the power input, a selection mechanism, a switching mechanism, an oscillator driving mechanism coupled to the switching mechanism, and an oscillator coupled to the charge pump portion and to the oscillator driving mechanism. The method of operation can include providing a first or second selection signal from a selection mechanism associated with the outputting of a DC input power or DC output power from a switching mechanism, respectively. These signals, along with an oscillator driving signal from an oscillator driving mechanism, can be used to initiate and maintain oscillation of an oscillator at a steady-state frequency within a predetermined range of frequencies.

Claims

1. A gyroscope with reduced start-up time comprising:

a power input configured to receive DC input power from an external power source, wherein the DC input power comprises a first voltage amplitude;

a charge pump portion coupled to the power input, wherein the charge pump portion is configured to receive the DC input power from the external power source, and configured to provide DC output power, wherein the DC output power comprises a second voltage amplitude, wherein the second voltage amplitude is greater than the first voltage amplitude;

a selection mechanism configured to provide a first selection signal or a second selection signal;

a switching mechanism coupled to the power input, to the charge pump portion, and to the selection mechanism, wherein the switching mechanism is configured to receive the DC input power and the DC output power, wherein the switching mechanism is configured to output the DC input power in response to the first selection signal, and wherein the switching mechanism is configured to output the DC output power, in response to the second selection signal;

an oscillator driving mechanism coupled to the switching mechanism, wherein the oscillator driving mechanism is configured to receive either the DC input power or the DC output power from the switching mechanism, wherein the oscillator driving mechanism is configured to output an oscillator driving signal having a first amplitude in response to the DC input power or having a second amplitude in response to the DC output power, wherein the second amplitude is greater than the first amplitude; and

an oscillator coupled to the charge pump portion and to the oscillator driving mechanism, wherein the oscillator comprises a fixed electrode and a moving electrode, wherein the fixed electrode is configured to receive the DC output power, wherein the moving electrode is configured to receive the oscillator driving signal, and wherein the oscillator is configured to oscillate in a steady-state at a given frequency in response to the DC output power and in response to the oscillator driving signal.

2. The gyroscope of claim 1 further comprising a timing mechanism coupled to the switching mechanism, wherein the timing mechanism is configured to output the second selection signal for a first period of time and then configured to output the first selection signal.

3. The gyroscope of claim 2 wherein the first period of time is within a range of about 5 milliseconds to about 20 milliseconds.

4. The gyroscope of claim 1 further comprising a control mechanism coupled to the switching mechanism and to the oscillator, wherein the control mechanism is configured to monitor a given frequency of the oscillator, wherein the control mechanism is configured to output the second selection signal when the given frequency of the oscillator is below a threshold frequency, and wherein the control mechanism is configured to output the first selection signal when the given frequency of the oscillator is above the threshold frequency.

5. The gyroscope of claim 4 wherein the threshold frequency is a fraction of the given frequency.

6. The gyroscope of claim 1 further comprising a control mechanism coupled to the switching mechanism and to the oscillator, wherein the control mechanism is configured to monitor an oscillation amplitude of the oscillator, wherein the control mechanism is configured to output the second selection signal when the oscillation amplitude of the oscillator is below a threshold amplitude, and wherein the control mechanism is configured to output the first selection signal when the oscillation amplitude of the oscillator is above the threshold amplitude.

7. The gyroscope of claim 6 wherein the threshold amplitude is less than or equal to the first voltage amplitude.

8. The gyroscope of claim 1

wherein the first voltage amplitude of the DC input power is within a range of about 1.8 to about 2.4 volts;

and

wherein the second voltage amplitude of the DC output power is within a range of about 5 to about 30 volts.

9. The gyroscope of claim 1 wherein the oscillator is configured to oscillate at a steady-state frequency within a range of about 2 KHz to about 100 KHz.

10. The gyroscope of claim 1 wherein the oscillator driving mechanism is configured to output the oscillator driving signal having an amplitude within a range of about 5 volts to about 30 volts in response to the DC output power or having an amplitude within a range of about 1.8 to about 2.4 volts in response to the DC input power.

11. A method for operating a gyroscope comprising:

receiving DC input power from an external power source, wherein the DC input power comprises a first voltage amplitude;

providing a DC output power from a charge pump, wherein the charge pump is configured to receive the DC input power from the external power source, wherein the DC output power comprises a second voltage amplitude, wherein the second voltage amplitude is greater than the first voltage amplitude;

outputting, from a selection mechanism, a first selection signal or a second selection signal;

receiving, in a switching mechanism, the DC input power from the external power source and the DC output power from the charge pump;

outputting, from the switching mechanism, the DC input power in response to a first selection signal, or the DC output power, in response to a second selection signal;

receiving, in an oscillator driving mechanism, the DC input power or the DC output power;

outputting, from the oscillator driving mechanism, an oscillator driving signal having a first amplitude in response to the DC input power or having a second amplitude in response to the DC output power, wherein the second amplitude is greater than the first amplitude;

providing, to an oscillator comprising a fixed electrode and a moving electrode, the DC output power for the fixed electrode and the oscillator driving signal for the moving electrode;

initiating oscillation of the moving electrode with respect to the fixed electrode in the oscillator in response to the DC output power and to the oscillator driving signal; and

maintaining oscillation of the moving electrode with respect to the fixed electrode at a steady-state frequency within a predetermined range of frequencies in response to the DC input power and in response to the oscillator driving signal.

12. The method of claim 11 wherein

outputting, from the selection mechanism, a first selection signal or a second selection signal comprises outputting the second selection signal for a first period of time and then the first selection signal.

13. The method of claim 12 wherein the first period of time is within a range of about 5 milliseconds to about 20 milliseconds.

14. The method of claim 11 further comprising

monitoring, in the selection mechanism, a given frequency of the oscillator;

and

wherein outputting, from the selection mechanism, the first selection signal or the second selection signal comprises;

outputting the second selection signal when the given frequency of the oscillator is below a threshold frequency; and

outputting the first selection signal when the given frequency of the oscillator is above the threshold frequency.

15. The method of claim 14 wherein the threshold frequency is a fraction of the given frequency.

16. The method of claim 11 further comprising

monitoring, in the selection mechanism, an oscillation amplitude of the oscillator;

and

wherein outputting, from the selection mechanism, the first selection signal or the second selection signal comprises;

outputting the second selection signal when the oscillation amplitude of the oscillator is below a threshold amplitude; and

outputting the second selection signal when the oscillation amplitude of the oscillator is above the threshold amplitude.

17. The method of claim 16 wherein the threshold amplitude is less than or equal to the first voltage amplitude.

18. The method of claim 11

wherein the first voltage amplitude of the DC input power is within a range of about 1.8 to about 2.4 volts;

and

wherein the second voltage amplitude of the DC output power is within a range of about 5 to about 30 volts.

19. The method of claim 11 wherein the steady-state frequency is within a range of about 2 KHz to about 100 KHz.

20. The method of claim 11 wherein the oscillator driving signal comprises an amplitude within a range of about 5 volts to about 30 volts in response to the DC output power or an amplitude within a range of about 1.8 volts to about 2.4 volts in response to the DC input power.