IP Library › Granted Patent US 8,220,329
Granted Patent B2
US 8,220,329 · App. 12/408,536 · Granted Jul 17, 2012

Management system for MEMS inertial sensors

Assignee: Analog Devices, Inc.
View Patent ↗
Loading inventors, assignments & file history…
Monitor This Case
Get email alerts when status or documents change.
Order Certified Copies
Most orders are placed with the USPTO same day — all within 24 business hours.
Order via The Patent Place →
Pre-filled with this patent's details
Quick Facts
Patent No.
US 8,220,329
App. No.
12/408,536
Granted
Jul 17, 2012
Kind
B2
Abstract

A MEMS system includes an inertial sensor having sensor circuitry and management circuitry implemented with the sensor circuitry. The management circuitry includes a detection module that detects a condition of the system and a management module that coordinates the functionality of the inertial sensor and the detection module based on the detected condition.

Claims (27)

1. A MEMS system that interacts with a microprocessor, the MEMS system comprising:

a MEMS inertial sensor configured to detect motion and produce data values related to the detected motion;

memory operatively coupled with the MEMS inertial sensor, the memory being configured to receive and store the data values from the MEMS inertial sensor;

a detection module operatively coupled with the MEMS inertial sensor and the memory, the detection module being configured to process the data values and to detect an inertial state of the MEMS inertial sensor based on the processed data values, the inertial state including an active state and an inactive state, the MEMS system configured to store the data values, the processed data values, or both in the memory in both the active state and the inactive state, the detection module being configured to detect an amount of data stored in the memory; and

a management module operatively coupled with the detection module and the memory, the management module being configured to receive the detected inertial state of the MEMS inertial sensor from the detection module, the management module being configured to signal the microprocessor to read the data values stored in the memory based on the inertial state and/or the amount of the data stored in the memory.

2. The system of claim 1 , further comprising the microprocessor in communication with the management module and the memory.

3. The system of claim 1 , wherein the memory stores the data values received by the inertial sensor in a first-in-first-out buffer type of configuration, a stream buffer type of configuration, or both.

4. The system of claim 1 , wherein the inertial state further includes free fall detection, tap detection, double tap detection, and change in orientation detection.

5. The system of claim 4 , wherein the memory stores the data values in a stream buffer type of configuration when in one inertial state, and the memory stores the data values in a first-in-first-out buffer type of configuration when in another inertial state.

6. The system of claim 1 , wherein the detection module detects the active state by calculating a change in acceleration and comparing the change in acceleration to a threshold, wherein the change in acceleration is determined using an acceleration bias captured by the inertial sensor and a measured acceleration produced by the inertial sensor.

7. The system of claim 6 , wherein the measured acceleration produced by the inertial sensor is measured at a sample rate, and the management module modifies the sample rate when the active state is detected.

8. The system of claim 1 , wherein the detection module detects the inactive state by calculating a change in acceleration, comparing the change in acceleration to a threshold, determining if the change in acceleration is less than the threshold, and if the change in acceleration is less than the threshold, determining if a predetermined period of time has elapsed, wherein the change in acceleration is determined using an acceleration bias captured by the inertial sensor and a measured acceleration produced by the inertial sensor.

9. The system of claim 8 , wherein the measured acceleration produced by the inertial sensor is measured at a sample rate, and the management module modifies the sample rate when the inactive state is detected.

10. The system of claim 1 , wherein the inertial sensor is formed on a die and the management module is formed on or in the die.

11. The system of claim 1 , wherein the management module is formed on or in a first die, and the MEMS inertial sensor is formed on or in a second die that is in communication with the first die.

12. The system of claim 1 , wherein the inertial sensor is an accelerometer.

13. The system of claim 1 , wherein the inertial sensor is a gyroscope.

14. A management system for a MEMS inertial sensor, the system comprising:

memory configured to receive and store data values from the MEMS inertial sensor;

a detection module operatively coupled with the memory, the detection module being configured to process the data values and to detect an inertial state of the MEMS inertial sensor based on the processed data values, the inertial state including an active state and an inactive state, the management system configured to store the data values, the processed data values, or both in the memory in both the active state and the inactive state, the detection module being configured to detect an amount of data stored in the memory; and

a management module operatively coupled with the detection module and the memory, the management module being configured to receive the detected inertial state of the MEMS inertial sensor from the detection module and to modify a configuration of the memory based on the detected inertial state.

15. The management system of claim 14 , wherein the management module is further configured to signal a microprocessor to read the data values stored in the memory based on the inertial state and/or the amount of the data stored in the memory.

16. The management system of claim 14 , wherein the configuration of the memory is a first-in-first-out buffer type of configuration, a stream buffer type of configuration, or both.

17. The management system of claim 14 , wherein the inertial state further includes free fall detection, tap detection, double tap detection, and change in orientation detection.

18. The management system of claim 17 , wherein the management module modifies the configuration of the memory to a stream buffer type of configuration when in one inertial state, and modifies the configuration of the memory to a first-in-first-out type of configuration when in another inertial state.

19. The management system of claim 14 , wherein the MEMS inertial sensor is an accelerometer.

20. The management system of claim 14 , wherein the MEMS inertial sensor is a gyroscope.

Assignments (1)
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded May 26, 2009
From: LEE, JAMES M.
To: ANALOG DEVICES, INC.
Reel/Frame 022733/0605 →
Continuity (4)
Provisional Application 61038594 · Mar 21, 2008
Provisional Application 61049590 · May 1, 2008
Provisional Application 61078923 · Jul 8, 2008
Related Publication 20090293615A1 · Dec 3, 2009